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Ansa-Addo EA, Thaxton J, Hong F, Wu BX, Zhang Y, Fugle CW, Metelli A, Riesenberg B, Williams K, Gewirth DT, Chiosis G, Liu B, Li Z. Clients and Oncogenic Roles of Molecular Chaperone gp96/grp94. Curr Top Med Chem 2017; 16:2765-78. [PMID: 27072698 DOI: 10.2174/1568026616666160413141613] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 09/07/2015] [Accepted: 01/17/2016] [Indexed: 12/18/2022]
Abstract
As an endoplasmic reticulum heat shock protein (HSP) 90 paralogue, glycoprotein (gp) 96 possesses immunological properties by chaperoning antigenic peptides for activation of T cells. Genetic studies in the last decade have unveiled that gp96 is also an essential master chaperone for multiple receptors and secreting proteins including Toll-like receptors (TLRs), integrins, the Wnt coreceptor, Low Density Lipoprotein Receptor-Related Protein 6 (LRP6), the latent TGFβ docking receptor, Glycoprotein A Repetitions Predominant (GARP), Glycoprotein (GP) Ib and insulin-like growth factors (IGF). Clinically, elevated expression of gp96 in a variety of cancers correlates with the advanced stage and poor survival of cancer patients. Recent preclinical studies have also uncovered that gp96 expression is closely linked to cancer progression in multiple myeloma, hepatocellular carcinoma, breast cancer and inflammation-associated colon cancer. Thus, gp96 is an attractive therapeutic target for cancer treatment. The chaperone function of gp96 depends on its ATPase domain, which is structurally distinct from other HSP90 members, and thus favors the design of highly selective gp96-targeted inhibitors against cancer. We herein discuss the strategically important oncogenic clients of gp96 and their underlying biology. The roles of cell-intrinsic gp96 in T cell biology are also discussed, in part because it offers another opportunity of cancer therapy by manipulating levels of gp96 in T cells to enhance host immune defense.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - Zihai Li
- Department of Microbiology and Immunology, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29466, USA.
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Integrin-mediated cell-matrix interaction in physiological and pathological blood vessel formation. JOURNAL OF ONCOLOGY 2011; 2012:125278. [PMID: 21941547 PMCID: PMC3175391 DOI: 10.1155/2012/125278] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Accepted: 07/15/2011] [Indexed: 02/07/2023]
Abstract
Physiological as well as pathological blood vessel formation are fundamentally dependent on cell-matrix interaction. Integrins, a family of major cell adhesion receptors, play a pivotal role in development, maintenance, and remodeling of the vasculature. Cell migration, invasion, and remodeling of the extracellular matrix (ECM) are integrin-regulated processes, and the expression of certain integrins also correlates with tumor progression. Recent advances in the understanding of how integrins are involved in the regulation of blood vessel formation and remodeling during tumor progression are highlighted. The increasing knowledge of integrin function at the molecular level, together with the growing repertoire of integrin inhibitors which allow their selective pharmacological manipulation, makes integrins suited as potential diagnostic markers and therapeutic targets.
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68Ga-DOTA-RGD peptide: biodistribution and binding into atherosclerotic plaques in mice. Eur J Nucl Med Mol Imaging 2011; 36:2058-67. [PMID: 19629477 DOI: 10.1007/s00259-009-1220-z] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Accepted: 07/01/2009] [Indexed: 10/20/2022]
Abstract
PURPOSE Increased expression of αvβ3/αvβ5 integrin is involved in angiogenesis and the inflammatory process in atherosclerotic plaques. The novel 68Ga-DOTA-RGD peptide binds with high affinity to αvβ3/αvβ5 integrin. The aim of this study was to investigate the uptake of the 68Ga-DOTA-RGD peptide in atherosclerotic plaques. METHODS Uptake of intravenously administered 68Ga-DOTA-RGD peptide was studied ex vivo in excised tissue samples and aortic sections of LDLR-/-ApoB100/100 atherosclerotic mice. The uptake of the tracer in aortic cryosections was examined by using digital autoradiography. Subsequently, the autoradiographs were combined with histological and immunohistological analysis of the sections. RESULTS DOTA-RGD peptide was successfully labelled with the generator-produced 68Ga. The tracer had reasonably good specific radioactivity (8.7 ± 1.1 GBq/μmol) and was quite stable in vivo. According to ex vivo biodistribution results, 68Ga-DOTA-RGD was cleared rapidly from the blood circulation and excreted through the kidneys to the urine with high radioactivity in the intestine, lungs, spleen and liver. Autoradiography results showed significantly higher uptake of 68Ga-DOTA-RGD peptide in the atherosclerotic plaques compared to healthy vessel wall (mean ratio ± SD 1.4 ± 0.1, p = 0.0004). Conclusion We observed that 68Ga-DOTA-RGD is accumulated into the plaques of atherosclerotic mice. However, this data only shows the feasibility of the approach, while the clinical significance still remains to be proven. Further studies are warranted to assess the uptake of this tracer into human atherosclerotic plaques.
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4
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Role of myosin light chain kinase and myosin light chain phosphatase in the resistance arterial myogenic response to intravascular pressure. Arch Biochem Biophys 2011; 510:160-73. [DOI: 10.1016/j.abb.2011.02.024] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Revised: 02/24/2011] [Accepted: 02/28/2011] [Indexed: 12/19/2022]
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Heroux J, Gharib AM, Danthi NS, Cecchini S, Ohayon J, Pettigrew RI. High-affinity alphavbeta3 integrin targeted optical probe as a new imaging biomarker for early atherosclerosis: initial studies in Watanabe rabbits. Mol Imaging Biol 2010; 12:2-8. [PMID: 19898904 DOI: 10.1007/s11307-009-0242-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2008] [Revised: 02/17/2009] [Accepted: 03/03/2009] [Indexed: 01/12/2023]
Abstract
PURPOSE A newly developed synthetic alpha v beta 3 integrin targeted optical probe (ITOP) has been demonstrated to target cancer cells, in vivo. Compared to the commercially available cyclic peptide c[RGDfv], this optical probe has at least 20 times better binding affinity for the alpha v beta 3 receptor. The present in vitro study was designed to investigate the possibility of detecting early atherosclerotic plaque by using this ITOP. PROCEDURES Experiments were performed on five Watanabe heritable hyperlipidemic rabbits and two New Zealand White rabbits for control. Our ITOP was used for detecting the presence of alpha v beta 3 receptors in vitro. RESULTS Segments of plaque accumulation from two distinct regions of ascending and descending aortas were labeled in Watanabe rabbits. The signal was found principally in the adventitia and proximal intima of the aortic vessel, corresponding directly to the expression of integrin alpha v beta 3 as determined by antibody assay. Moreover, there was a close association between the level of labeling with the alpha v beta 3 targeted probe and the thickness of the adventitia. CONCLUSIONS This high-affinity ITOP identifies the site and extent of alpha v beta 3 expression and correlates with adventitial thickness. Recent evidence associates alpha v beta 3 expression with the inflammatory process in early vulnerable plaque, making this compound a promising potential biomarker for early atherosclerotic disease.
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Affiliation(s)
- Julie Heroux
- Laboratory of Integrative Cardiovascular Imaging Science, National Institute of Diabetes Digestive and Kidney Diseases, Bethesda, MD 20892, USA.
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6
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The role of cell adhesion pathways in angiogenesis. Int J Biochem Cell Biol 2008; 41:521-30. [PMID: 18762270 DOI: 10.1016/j.biocel.2008.05.030] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2008] [Revised: 05/16/2008] [Accepted: 05/21/2008] [Indexed: 02/06/2023]
Abstract
Angiogenesis, the formation of new blood vessels from pre-existing vasculature, is prevalent both during normal mammalian development and in certain pathological conditions such as tumor growth. It is stimulated and controlled by a complex network of intracellular signaling mechanisms, many of which are initiated by trans-membrane receptors transducing signals received from other cells and from the extracellular environment. Of these, cytokine signaling is recognized as one of the primary drivers of angiogenesis, but it has become increasingly evident that signaling mechanisms generated as a result of cell adhesion interactions are also crucially important. In addition, cell adhesion pathways are also intimately tied to cytokine signaling often making it difficult to dissect out the relative contribution of each to a particular angiogenic step. Many of these same signaling mechanisms are often manipulated by tumors to stimulate aberrant angiogenesis and enhance their blood supply. As a consequence, there is a great deal of interest in trying to understand the full complement of intracellular signaling pathways in angiogenesis as well as their interplay and timing during the process. Ultimately, understanding the complex network of signaling pathways that function during angiogenesis will provide important avenues for future therapeutic development.
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7
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Lu X, Lu D, Scully M, Kakkar V. The Role of Integrins in Cancer and the Development of Anti-Integrin Therapeutic Agents for Cancer Therapy. PERSPECTIVES IN MEDICINAL CHEMISTRY 2008. [DOI: 10.1177/1177391x0800200003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Integrins have been reported to mediate cell survival, proliferation, differentiation, and migration programs. For this reason, the past few years have seen an increased interest in the implications of integrin receptors in cancer biology and tumor cell aggression. This review considers the potential role of integrins in cancer and also addresses why integrins are present attractive targets for drug design. It discusses of the several properties of the integrin-based chemotherapeutic agents currently under consideration clinically and provides an insight into cancer drug development using integrin as a target.
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Affiliation(s)
- Xinjie Lu
- Thrombosis Research Institute, Manresa Road, London, SW3 6LR U.K
| | - Dong Lu
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, U.K
| | - Mike Scully
- Thrombosis Research Institute, Manresa Road, London, SW3 6LR U.K
| | - Vijay Kakkar
- Thrombosis Research Institute, Manresa Road, London, SW3 6LR U.K
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8
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Wu J, Liu W, Sousa E, Qiu Y, Pittman DD, Maganti V, Feldman J, Gill D, Lu Z, Dorner AJ, Schaub R, Tan XY. Proteomic identification of endothelial proteins isolated in situ from atherosclerotic aorta via systemic perfusion. J Proteome Res 2007; 6:4728-36. [PMID: 17997517 DOI: 10.1021/pr070537c] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The functional and structural alterations of vascular endothelium contribute to the initiation, progression, and complications of atherosclerotic plaque formation, but limited information is known about the molecular composition and pathways underlying pathological changes during atherosclerosis. We have developed an affinity proteomic strategy for in situ isolation and differential mapping of vascular endothelial proteins in normal and atherosclerotic aorta tissues. The selective labeling was carried out by perfusion of the blood vessels with an active biotin reagent for covalent modification of accessible vascular endothelial proteins. The biotinylated proteins were then enriched by streptavidin affinity chromatography, separated by SDS-PAGE, and subsequently characterized by LC-MS/MS. The described procedure led to the identification of 454 distinct proteins in normal and atherosclerotic aorta tissues. A majority of the proteins are plasma membrane associated and extracellular matrix proteins, and 81 showed altered expressions in atherosclerotic aorta tissue. The differentially expressed proteins are involved in immune and inflammatory responses, cell adhesion, and lipid metabolism. The method provides a new avenue for investigating the endothelial dysfunction and development of atherosclerosis.
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Affiliation(s)
- Jiang Wu
- Biological Technologies, Cardiovascular and Metabolic Diseases, Wyeth Research, Cambridge, Massachusetts 02140, USA
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Im E, Kazlauskas A. PtdIns-4,5-P2 as a potential therapeutic target for pathologic angiogenesis. Expert Opin Ther Targets 2007; 11:443-51. [PMID: 17373875 DOI: 10.1517/14728222.11.4.443] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A variety of diseases arise, at least in part, when the events controlling the formation and stability of blood vessels are deregulated. For instance, the growth and survival of solid tumors are tightly linked to their ability to undergo vascularization. Similarly, pathologic angiogenesis of the retina or choroid underscores blinding diseases that afflict a substantial percentage of the world's population. Therefore, it is of great interest to develop antiangiogenic drugs that will relieve the burden of vascular diseases such as cancer, age-related macular degeneration and proliferative diabetic retinopathy. In this article, the authors highlight their recent discovery that PtdIns-4,5-P2)can regulate vessel stability. This finding identifies PtdIns-4,5-P2 as a novel target for angiogenesis therapies.
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Affiliation(s)
- Eunok Im
- Schepens Eye Research Institute, Harvard Medical School, 20 Staniford Street, Boston, MA 02114, USA
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10
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Robert R, Jacobin-Valat MJ, Daret D, Miraux S, Nurden AT, Franconi JM, Clofent-Sanchez G. Identification of human scFvs targeting atherosclerotic lesions: selection by single round in vivo phage display. J Biol Chem 2006; 281:40135-43. [PMID: 17068330 DOI: 10.1074/jbc.m609344200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Our aim was to investigate by in vivo biopanning the lesions developed early in atherosclerosis and identify human antibodies that home to diseased regions. We have designed a two-step approach for a rapid isolation of human Monoclonal phage-display single-chain antibodies (MoPhabs) reactive with proteins found in lesions developed in an animal model of atherosclerosis. After a single round of in vivo biopanning, the MoPhabs were eluted from diseased sections of rabbit aorta identified by histology and NMR microscopy. MoPhabs expressed in situ were selected by subtractive colony filter screening for their capacity to recognize atherosclerotic but not normal aorta. MoPhabs selected by our method predominantly bind atherosclerotic lesions. Two of them, B3.3G and B3.GER, produced as scFv fragments, recognized an epitope present on the surface in early atherosclerotic lesions and within the intimal thickness in more complex plaques. These human MoPhabs homed to atherosclerotic lesions in ApoE(-/-) mice after in vivo injection. A protein of approximately 56 kDa recognized by B3.3G was affinity-purified and identified by mass spectrometry analysis as vitronectin. This is the first time that single round in vivo biopanning has been used to select human antibodies as candidates for diagnostic imaging and for obtaining insight into targets displayed in atherosclerotic plaques.
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Affiliation(s)
- Rémy Robert
- Résonance Magnétique des Systèmes Biologiques, Centre National Recherche Scientifique (CNRS), UMR 5536, Université Bordeaux 2 Victor Ségalen, 146 rue Léo Saignat, 33076 Bordeaux, France.
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11
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Rodgers UR, Weiss AS. Integrin αvβ3 binds a unique non-RGD site near the C-terminus of human tropoelastin. Biochimie 2004; 86:173-8. [PMID: 15134831 DOI: 10.1016/j.biochi.2004.03.002] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2003] [Accepted: 03/11/2004] [Indexed: 11/22/2022]
Abstract
Tropoelastin is the soluble precursor of the essential resilient connective tissue protein elastin. We examined the binding of integrin alpha(v)beta(3) to tropoelastin. In quantitative colorimetric solid-phase assays, purified alpha(v)beta(3) demonstrated saturable, divalent cation-dependent, single-site binding behavior on tropoelastin with a dissociation constant of 3.8 +/- 0.9 nM in the presence of 1 mM Mn(2+) which increased to 23 +/- 5 nM in the presence of 1 mM Ca(2+). Association with alpha(v)beta(3) was localized to the C-terminal 16 residues of tropoelastin, encompassing the region encoded by exon 36. This region comprises a unique disulfide loop in tropoelastin that is not essential for the interaction. This is the first identification of a specific, single binding site on tropoelastin and the first observation of direct binding of an integrin to a tropoelastin domain.
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Affiliation(s)
- U R Rodgers
- School of Molecular and Microbial Biosciences, University of Sydney, Building G08, Sydney, NSW 2006, Australia
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Martinez-Lemus LA, Hill MA, Bolz SS, Pohl U, Meininger GA. Acute mechanoadaptation of vascular smooth muscle cells in response to continuous arteriolar vasoconstriction: implications for functional remodeling. FASEB J 2004; 18:708-10. [PMID: 14977879 DOI: 10.1096/fj.03-0634fje] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Arterioles exposed to norepinephrine (NE) for 4 h exhibit incomplete relaxation on removal of the agonist. We hypothesized that this is due to a mechanoadaptation process associated with active repositioning of vascular smooth muscle cells (VSMCs) within the vascular wall. Isolated arterioles were exposed to NE (10(-5.5) M) for either 5 min (n = 7) or 4 h (n = 13). During the 5-min exposure, vessel diameter was reduced to 61 +/- 2.6%, and cells shortened to 76.3 +/- 3.8% of control. After NE removal, vessel diameter and cell length returned to control values, which indicated that during acute vasoconstriction cells shorten and relengthen in a reversible fashion. In contrast, when NE exposure lasted 4 h, vessels did not return to control diameter, but VSMCs returned to control length after NE removal. During the 4-h constriction, 56% of the VSMCs began returning to control length, and the overlap between VSMCs increased, which indicated that cellular repositioning had occurred in the presence of the maintained constriction. Thus, in response to prolonged constriction, VSMCs undergo a mechanoadaptation process involving "length autoregulation" that would be energetically favorable for maintenance of a reduced diameter and may provide a mechanism for the development of eutrophic remodeling of the vascular wall.
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Affiliation(s)
- Luis A Martinez-Lemus
- Cardiovascular Research Institute-Division of Vascular Biology, Texas A&M University System Health Science Center, College Station, Texas 77843-1114, USA
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Durier S, Fassot C, Laurent S, Boutouyrie P, Couetil JP, Fine E, Lacolley P, Dzau VJ, Pratt RE. Physiological genomics of human arteries: quantitative relationship between gene expression and arterial stiffness. Circulation 2003; 108:1845-51. [PMID: 14530203 DOI: 10.1161/01.cir.0000091407.86925.7a] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND Previous genomic studies with human tissues have compared differential gene expression between 2 conditions (ie, normal versus diseased) to identify altered gene expression in a binary manner; however, a potentially more informative approach is to correlate the levels of gene expression with quantitative physiological parameters. METHODS AND RESULTS In this study, we have used this approach to examine genes whose expression correlates with arterial stiffness in human aortic specimens. Our data identify 2 distinct groups of genes, those associated with cell signaling and those associated with the mechanical regulation of vascular structure (cytoskeletal-cell membrane-extracellular matrix). Although previous studies have concentrated on the contribution of the latter group toward arterial stiffness, our data suggest that changes in expression of signaling molecules play an equally important role. Alterations in the profiles of signaling molecules could be involved in the regulation of cell cytoskeletal organization, cell-matrix interactions, or the contractile state of the cell. CONCLUSIONS Although the influence of smooth muscle contraction/relaxation on arterial stiffness could be controversial, our provocative data would suggest that further studies on this subject are indicated.
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Affiliation(s)
- Séverine Durier
- Department of Pharmacology and INSERM EMI 107, Paris, France
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14
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Konttinen YT, Mackiewicz Z, Povilenaite D, Sukura A, Hukkanen M, Virtanen I. Disease-associated increased HIF-1, alphavbeta3 integrin, and Flt-1 do not suffice to compensate the damage-inducing loss of blood vessels in inflammatory myopathies. Rheumatol Int 2003; 24:333-9. [PMID: 13680145 DOI: 10.1007/s00296-003-0379-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2002] [Accepted: 07/06/2003] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To analyze the microvascular network in skeletal muscle biopsies from patients with dermatomyositis (DM) and systemic sclerosis (SSc) compared to polymyositis (PM) and systemic lupus erythematosus (SLE), and non-inflammatory myopathies, and to clarify whether reparative angiogenesis-related factors are expressed in parallel to blood vessel damage. METHODS Immunohistochemical staining of muscle biopsies (10 DM, 10 SSc, 10 PM, 10 SLE, and 10 non-inflammatory myopathies) with antibodies against von Willebrand factor (vWF), hypoxia-inducible factor-1beta (HIF-1beta), beta3 integrin subunit, and vascular endothelial growth factor receptor-1 (VEGFR-1). The TechMate staining robot and biotin-streptavidin protocol were used. RESULTS DM and SSc muscles were characterized by endothelial damage and reduction of blood vessel network. Expression of angiogenesis-related factors (HIF-1beta, beta3, VEGFR-1) was also found in the same biopsies. In contrast, in PM and SLE muscles, vascular networks were apparently not affected and angiogenic stimuli were less expressed if at all. CONCLUSIONS This work demonstrates that in inflamed muscles hypoxia/ischemia induces increased expression of angiogenic factors, yet their impact is insufficient to repair disease-associated reduction of the capillary network. This leads to questions considering the usefulness of angiogenic factors in the treatment of ischemic inflammatory myopathies in DM and SSc.
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Affiliation(s)
- Yrjö T Konttinen
- Department of Medicine/Invärtes medicin, Biomedicum, P.O. Box 700, 00029 Helsinki University Central Hospital, Helsinki, Finland.
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15
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Fox RJ, Frame MD. Arteriolar flow recruitment with vitronectin receptor stimulation linked to remote wall shear stress. Microvasc Res 2002; 64:414-24. [PMID: 12453436 DOI: 10.1006/mvre.2002.2451] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Our purpose was to investigate the hemodynamic mechanism of flow recruitment within arteriolar networks as stimulated by the vitronectin receptor. Since remote stimulation of the vitronectin receptor initiates a flow-mediated dilation, we tested whether the response could be mimicked by exogenous NO. Arteriolar diameter, red blood cell flux, and velocity were measured in terminal branch arterioles arising from a central feed (8-10 microm) arteriole (together previously defined as an arteriolar network) in the cheek pouch tissue of anesthetized hamsters (n = 29, pentobarbital 70 mg/kg). Terminal branch arterioles were stimulated (micropipette, 10 s) with 10 microg/ml LM609 (agonist, vitronectin receptor), 10(-4) M nitroprusside (SNP), or control. The same amount of flow was recruited into the network by applying LM609 or SNP to only one branch of the network; however, flow distribution differed. With LM609, all recruited flow went directly to the branch that was stimulated. With SNP, recruited flow was distributed evenly throughout the network, no matter where the stimulus was applied. Thus, flow-mediated dilation induced by vitronectin receptor stimulation initiates a robust flow recruitment response, directing flow to the stimulus flow path. In contrast, NO alone initiates flow recruitment to the entire network, along multiple parallel flow paths.
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Affiliation(s)
- Randall J Fox
- Department of Anesthesiology, Center for Cardiovascular Research, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA
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16
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Paulhe F, Perret B, Chap H, Iberg N, Morand O, Racaud-Sultan C. Phosphoinositide 3-kinase C2alpha is activated upon smooth muscle cell migration and regulated by alpha(v)beta(3) integrin engagement. Biochem Biophys Res Commun 2002; 297:261-6. [PMID: 12237112 DOI: 10.1016/s0006-291x(02)02065-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The involvement of phosphoinositide 3-kinase C2alpha in vascular smooth muscle cell migration was investigated. Products of phosphoinositide 3-kinase, phosphatidylinositol-3-phosphate, and phosphatidylinositol-3,4-bis-phosphate were increased upon smooth muscle cell migration but their synthesis was affected only partially by phosphoinositide 3-kinase inhibitors, wortmannin and LY-294002. Using specific antibody, we showed that the wortmannin/LY-294002 poorly sensitive phosphoinositide 3-kinase C2alpha is expressed in smooth muscle cells. Measurement of phosphoinositide 3-kinase C2alpha activity in vitro, after immunoprecipitation, clearly demonstrated its activation upon smooth muscle cell migration. Moreover, for the first time, phosphoinositide 3-kinase C2alpha was found to be differentially regulated by alpha(v)beta(3) and alpha(v)beta(5) integrin engagement. Finally, we have identified two new potential phosphoinositide 3-kinase C2alpha-binding proteins, p70 and p110, which both may be tyrosine phosphorylated. Thus, phosphoinositide 3-kinase C2alpha might represent a new regulatory pathway of cell migration downstream of integrin engagement.
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MESH Headings
- Androstadienes/pharmacology
- Animals
- Aorta/cytology
- Cell Movement/physiology
- Cells, Cultured
- Chromones/pharmacology
- Enzyme Activation
- Humans
- Inositol 1,4,5-Trisphosphate/metabolism
- Integrin alphaVbeta3/metabolism
- Integrins/metabolism
- Isoenzymes
- Morpholines/pharmacology
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/physiology
- Phosphatidylinositol 3-Kinases/metabolism
- Phosphatidylinositol Phosphates/metabolism
- Phosphoinositide-3 Kinase Inhibitors
- Phosphorylation
- Receptors, Vitronectin/metabolism
- Signal Transduction/physiology
- Swine
- Tyrosine/metabolism
- Wortmannin
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Affiliation(s)
- Frédérique Paulhe
- Institut Fédératif de Recherche Claude de Préval, INSERM, Unité 563, Hôpital Purpan, Toulouse Cedex F31059, France
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Paulhe F, Bogyo A, Chap H, Perret B, Racaud-Sultan C. Vascular smooth muscle cell spreading onto fibrinogen is regulated by calpains and phospholipase C. Biochem Biophys Res Commun 2001; 288:875-81. [PMID: 11688990 DOI: 10.1006/bbrc.2001.5859] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Fibrinogen deposition and smooth muscle cell migration are important causes of atherosclerosis and angiogenesis. Involvement of calpains in vascular smooth muscle cell adhesion onto fibrinogen was investigated. Using calpain inhibitors, we showed that activation of calpains was required for smooth muscle cell spreading. An increase of (32)P-labeled phosphatidic acid and phosphatidylinositol-3,4-bisphosphate, respective products of phospholipase C and phosphoinositide 3-kinase activities, was measured in adherent cells. Addition of the calpain inhibitor calpeptin strongly decreased phosphatidic acid and phosphatidylinositol-3,4-bisphosphate. However, smooth muscle cell spreading was prevented by the phospholipase C inhibitor U-73122, but poorly modified by phosphoinositide 3-kinase inhibitors wortmannin and LY-294002. Moreover, PLC was found to act upstream of the PI 3-kinase IA isoform. Thus, our data provide the first evidence that calpains are required for smooth muscle cell spreading. Further, phospholipase C activation is pointed as a key step of cell-spreading regulation by calpains.
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Affiliation(s)
- F Paulhe
- Institut Fédératif de Recherche Claude de Préval, INSERM, Unité 326, Hôpital Purpan, Toulouse cedex, F31059, France
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