1
|
Hunter EJ, Hamaia SW, Gullberg D, Malcor JD, Farndale RW. Selectivity of the collagen-binding integrin inhibitors, TC-I-15 and obtustatin. Toxicol Appl Pharmacol 2021; 428:115669. [PMID: 34363821 PMCID: PMC8444087 DOI: 10.1016/j.taap.2021.115669] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 07/29/2021] [Accepted: 08/02/2021] [Indexed: 11/22/2022]
Abstract
Integrins are a family of 24 adhesion receptors which are both widely-expressed and important in many pathophysiological cellular processes, from embryonic development to cancer metastasis. Hence, integrin inhibitors are valuable research tools which may have promising therapeutic uses. Here, we focus on the four collagen-binding integrins α1β1, α2β1, α10β1 and α11β1. TC-I-15 is a small molecule inhibitor of α2β1 that inhibits platelet adhesion to collagen and thrombus deposition, and obtustatin is an α1β1-specific disintegrin that inhibits angiogenesis. Both inhibitors were applied in cellular adhesion studies, using synthetic collagen peptide coatings with selective affinity for the different collagen-binding integrins and testing the adhesion of C2C12 cells transfected with each. Obtustatin was found to be specific for α1β1, as described, whereas TC-I-15 is shown to be non-specific, since it inhibits both α1β1 and α11β1 as well as α2β1. TC-I-15 was 100-fold more potent against α2β1 binding to a lower-affinity collagen peptide, suggestive of a competitive mechanism. These results caution against the use of integrin inhibitors in a therapeutic or research setting without testing for cross-reactivity.
Collapse
Affiliation(s)
- Emma J Hunter
- Department of Biochemistry, University of Cambridge, Downing Site, Cambridge CB2 1QW, UK
| | - Samir W Hamaia
- Department of Biochemistry, University of Cambridge, Downing Site, Cambridge CB2 1QW, UK
| | - Donald Gullberg
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, N-5009 Bergen, Norway
| | - Jean-Daniel Malcor
- Department of Biochemistry, University of Cambridge, Downing Site, Cambridge CB2 1QW, UK
| | - Richard W Farndale
- Department of Biochemistry, University of Cambridge, Downing Site, Cambridge CB2 1QW, UK.
| |
Collapse
|
2
|
Zhou B, Li M, Xu X, Yang L, Ye M, Chen Y, Peng J, Xiao L, Wang L, Huang S, Zhang L, Lin Q, Zhang Z. Integrin α 2β 1 Targeting DGEA-Modified Liposomal Doxorubicin Enhances Antitumor Efficacy against Breast Cancer. Mol Pharm 2021; 18:2634-2646. [PMID: 34134485 DOI: 10.1021/acs.molpharmaceut.1c00132] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Breast cancer was the leading cause of newly diagnosed cases of tumors in 2020, ranking as the second highest cause of female death. Chemotherapy remains the conventional treatment of choice for breast tumors in most clinical cases. However, it is often accompanied by a poor prognosis and severe side effects, resulting from an insufficient accumulation of the drug at tumor sites and an unsystematic distribution of the drug across the body. Inspired by the fact that breast tumor cells overexpress integrin α2β1 on the surface, we designed and constructed an integrin α2β1 targeting DGEA-modified liposomal doxorubicin (DGEA-Lipo-DOX) platform for application in breast cancer therapy. The DGEA-Lipo-DOX was stable with a uniform particle size of 121.1 ± 3.8 nm and satisfactory drug encapsulation. Demonstrated in vitro and in vivo, the constructed platform exhibited improved antitumor ability. The DGEA-Lipo-DOX showed 4-fold enhanced blood circulation and 6-fold increased accumulation of DOX at the tumor sites compared to those of free DOX, resulting in a significantly enhanced antitumor efficacy in tumor-bearing mice. A preliminary safety evaluation suggested that the systemic toxicity of DOX was relieved by DGEA-Lipo delivery. Collectively, binding integrin α2β1 by DGEA may represent an alternative therapeutic strategy for potentially safer breast cancer treatment.
Collapse
Affiliation(s)
- Bingjie Zhou
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, P.R. China
| | - Min Li
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, P.R. China
| | - Xiaomin Xu
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, P.R. China
| | - Lan Yang
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, P.R. China
| | - Meiling Ye
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, P.R. China
| | - Yan Chen
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, P.R. China
| | - Jiayi Peng
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, P.R. China
| | - Linyu Xiao
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, P.R. China
| | - Luyao Wang
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, P.R. China
| | - Shiqi Huang
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, P.R. China
| | - Ling Zhang
- College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, P.R. China
| | - Qing Lin
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, P.R. China
| | - Zhirong Zhang
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, P.R. China
| |
Collapse
|
3
|
Li B, Wang X, Wang R, Rutz B, Ciotkowska A, Gratzke C, Herlemann A, Spek A, Tamalunas A, Waidelich R, Stief CG, Hennenberg M. Inhibition of neurogenic and thromboxane A 2 -induced human prostate smooth muscle contraction by the integrin α2β1 inhibitor BTT-3033 and the integrin-linked kinase inhibitor Cpd22. Prostate 2020; 80:831-849. [PMID: 32449814 DOI: 10.1002/pros.23998] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 04/16/2020] [Accepted: 04/19/2020] [Indexed: 01/23/2023]
Abstract
INTRODUCTION Prostate smooth muscle contraction is critical for etiology and treatment of lower urinary tract symptoms in benign prostatic hyperplasia (BPH). Integrins connect the cytoskeleton to membranes and cells to extracellular matrix, what is essential for force generation in smooth muscle contraction. Integrins are composed of different subunits and may cooperate with integrin-linked kinase (ILK). Here, we examined effects of inhibitors for different integrin heterodimers and ILK on contraction of human prostate tissues. METHODS Prostate tissues were obtained from radical prostatectomy. Integrins and ILK were detected by Western blot, real-time polymerase chain reaction (RT-PCR), and double fluorescence staining. Smooth muscle contractions of prostate strips were studied in an organ bath. Contractions were compared after application of solvent (controls), the ILK inhibitor Cpd22 (N-methyl-3-(1-(4-(piperazin-1-yl)phenyl)-5-(4'-(trifluoromethyl)-[1,1'-biphenyl]-4-yl)-1H-pyrazol-3-yl)propanamide), the integrin α2β1 inhibitor BTT-3033 (1-(4-fluorophenyl)-N-methyl-N-[4[[(phenylamino)carbonyl]amino]phenyl]-1H-pyrazole-4-sulfonamide), or the integrin α4β1/α9β1 inhibitor BOP (N-(benzenesulfonyl)- l-prolyl- l-O-(1-pyrrolidinylcarbonyl)tyrosine sodium salt). RESULTS Western blot analyses of prostate tissues using antibodies raised against integrins α2b, α4, α9, β1, and ILK revealed bands matching the expected sizes of corresponding antigens. Expression of integrins and ILK was confirmed by RT-PCR. Individual variations of expression levels occurred independently from divergent degree of BPH, reflected by different contents of prostate-specific antigen. Double fluorescence staining of prostate sections using antibodies raised against integrins α2 and β1, or against ILK resulted in immunoreactivity colocalizing with calponin, suggesting localization in prostate smooth muscle cells. Electric field stimulation (EFS) induced frequency-dependent contractions, which were inhibited by Cpd22 (3 µM) and BTT-3033 (1 µM) (inhibition around 37% by Cpd22 and 46% by BTT-3033 at 32 Hz). The thromboxane A2 analog U46619-induced concentration-dependent contractions, which were inhibited by Cpd22 and BTT-3033 (around 67% by Cpd22 and 39% by BTT-3033 at 30 µM U46619). Endothelin-1 induced concentration-dependent contractions, which were not affected by Cpd22 or BTT-3033. Noradrenaline and the α1 -adrenergic agonists methoxamine and phenylephrine-induced concentration-dependent contractions, which were not or very slightly inhibited by Cpd22 and BTT-3033. BOP did not change EFS- or agonist-induced contraction. CONCLUSIONS Integrin α2β1 and ILK inhibitors inhibit neurogenic and thromboxane A2 -induced prostate smooth muscle contraction in human BPH. A role for these targets for prostate smooth muscle contraction may appear possible.
Collapse
Affiliation(s)
- Bingsheng Li
- Department of Urology, LMU Munich, University Hospital, Munich, Germany
| | - Xiaolong Wang
- Department of Urology, LMU Munich, University Hospital, Munich, Germany
| | - Ruixiao Wang
- Department of Urology, LMU Munich, University Hospital, Munich, Germany
| | - Beata Rutz
- Department of Urology, LMU Munich, University Hospital, Munich, Germany
| | - Anna Ciotkowska
- Department of Urology, LMU Munich, University Hospital, Munich, Germany
| | | | - Annika Herlemann
- Department of Urology, LMU Munich, University Hospital, Munich, Germany
| | - Annabel Spek
- Department of Urology, LMU Munich, University Hospital, Munich, Germany
| | | | | | - Christian G Stief
- Department of Urology, LMU Munich, University Hospital, Munich, Germany
| | - Martin Hennenberg
- Department of Urology, LMU Munich, University Hospital, Munich, Germany
| |
Collapse
|
4
|
Das Ghosh L, Hasan J, Jain A, Sundaresan NR, Chatterjee K. A nanopillar array on black titanium prepared by reactive ion etching augments cardiomyogenic commitment of stem cells. Nanoscale 2019; 11:20766-20776. [PMID: 31651003 DOI: 10.1039/c9nr03424b] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
A major impediment in the clinical translation of stem cell therapy has been the inability to efficiently and reproducibly direct differentiation of a large population of stem cells. Thus, we aimed to engineer a substrate for culturing stem cells to efficiently induce cardiomyogenic lineage commitment. In this work, we present a nanopillar array on the surface of titanium that was prepared by mask-less reactive ion etching. Scanning electron and atomic force microscopy revealed that the surface was covered by vertically aligned nanopillars each of ≈1 μm with a diameter of ≈80 nm. The nanopillars supported the attachment and proliferation of human mesenchymal stem cells (hMSCs). Cardiomyogenic lineage commitment of the stem cells was more enhanced on the nanopillars than on the smooth surface. When co-cultured with neonatal rat cardiomyocytes, the cyclic pattern of calcium transport observed distinctly in cells differentiated on the arrays compared to the cells cultured on the smooth surface was the functional validation of differentiation. The use of small molecule inhibitors revealed that integrins namely, α2β1 and αvβ3, are essential for cardiomyogenesis on the nanostructured surface, which is further mediated by FAK, Erk and Akt cell signaling pathways. This study demonstrates that the nanopillar array efficiently promotes the cardiomyogenic lineage commitment of stem cells via integrin-mediated signaling and can potentially serve as a platform for the ex vivo differentiation of stem cells toward cell therapy in cardiac tissue repair and regeneration.
Collapse
Affiliation(s)
- Lopamudra Das Ghosh
- Department of Materials Engineering, Indian Institute of Science, Bangalore 560012, India.
| | - Jafar Hasan
- Department of Materials Engineering, Indian Institute of Science, Bangalore 560012, India.
| | - Aditi Jain
- Centre for Biosystems Science and Engineering, Indian Institute of Science, Bangalore 560012, India.
| | - Nagalingam R Sundaresan
- Centre for Biosystems Science and Engineering, Indian Institute of Science, Bangalore 560012, India. and Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
| | - Kaushik Chatterjee
- Department of Materials Engineering, Indian Institute of Science, Bangalore 560012, India. and Centre for Biosystems Science and Engineering, Indian Institute of Science, Bangalore 560012, India.
| |
Collapse
|
5
|
Naci D, Vuori K, Aoudjit F. Alpha2beta1 integrin in cancer development and chemoresistance. Semin Cancer Biol 2015; 35:145-53. [PMID: 26297892 DOI: 10.1016/j.semcancer.2015.08.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 08/10/2015] [Accepted: 08/14/2015] [Indexed: 01/06/2023]
Abstract
Extracellular matrix, via its receptors the integrins, has emerged as a crucial factor in cancer development. The α2β1 integrin is a major collagen receptor that is widely expressed and known to promote cell migration and control tissue homeostasis. Growing evidence suggests that it can be a key pathway in cancer. Recent studies have shown that α2β1 integrin is a regulator of cancer metastasis either by promoting or inhibiting the dissemination process of cancer cells. The α2β1 integrin signaling can also enhance tumor angiogenesis. Emerging evidence supports a role for α2β1 integrin in cancer chemoresistance especially in hematological malignancies originating from the T cell lineage. In addition, α2β1 integrin has been associated with cancer stem cells. In this review, we will discuss the complex role of α2β1 integrin in these processes. Collagen is a major matrix protein of the tumor microenvironment and thus, understanding how α2β1 integrin regulates cancer pathogenesis is likely to lead to new therapeutic approaches and agents for cancer treatment.
Collapse
Affiliation(s)
- Dalila Naci
- Centre de recherche du CHU de Québec, Axe des maladies infectieuses et immunitaires and Département de Microbiologie-Immunologie, Faculté de Médecine, Université Laval, Québec, Canada
| | - Kristiina Vuori
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Fawzi Aoudjit
- Centre de recherche du CHU de Québec, Axe des maladies infectieuses et immunitaires and Département de Microbiologie-Immunologie, Faculté de Médecine, Université Laval, Québec, Canada.
| |
Collapse
|
6
|
Momic T, Katzhendler J, Shai E, Noy E, Senderowitz H, Eble JA, Marcinkiewicz C, Varon D, Lazarovici P. Vipegitide: a folded peptidomimetic partial antagonist of α2β1 integrin with antiplatelet aggregation activity. Drug Des Devel Ther 2015; 9:291-304. [PMID: 25609915 PMCID: PMC4294129 DOI: 10.2147/dddt.s72844] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Linear peptides containing the sequence WKTSRTSHY were used as lead compounds to synthesize a novel peptidomimetic antagonist of α2β1 integrin, with platelet aggregation-inhibiting activity, named Vipegitide. Vipegitide is a 13-amino acid, folded peptidomimetic molecule, containing two α-aminoisobutyric acid residues at positions 6 and 8 and not stable in human serum. Substitution of glycine and tryptophan residues at positions 1 and 2, respectively, with a unit of two polyethylene glycol (PEG) molecules yielded peptidomimetic Vipegitide-PEG2, stable in human serum for over 3 hours. Vipegitide and Vipegitide-PEG2 showed high potency (7×10(-10) M and 1.5×10(-10) M, respectively) and intermediate efficacy (40% and 35%, respectively) as well as selectivity toward α2 integrin in inhibition of adhesion of α1/α2 integrin overexpressing cells toward respective collagens. Interaction of both peptidomimetics with extracellular active domain of α2 integrin was confirmed in cell-free binding assay with recombinant α2 A-domain. Integrin α2β1 receptor is found on the platelet membrane and triggers collagen-induced platelet aggregation. Vipegitide and Vipegitide-PEG2 inhibited α2β1 integrin-mediated adhesion of human and murine platelets under the flow condition, by 50%. They efficiently blocked adenosine diphosphate- and collagen I-induced platelet aggregation in platelet rich plasma and whole human blood. Higher potency of Vipegitide than Vipegitide-PEG2 is consistent with results of computer modeling of the molecules in water. These peptidomimetic molecules were acutely tolerated in mice upon intravenous bolus injection of 50 mg/kg. These results underline the potency of Vipegitide and Vipegitide-PEG2 molecules as platelet aggregation-inhibiting drug lead compounds in antithrombotic therapy.
Collapse
Affiliation(s)
- Tatjana Momic
- School of Pharmacy Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Jehoshua Katzhendler
- School of Pharmacy Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ela Shai
- Department of Hematology, Coagulation Unit, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Efrat Noy
- Department of Chemistry, Bar-Ilan University, Ramat-Gan, Israel
| | | | - Johannes A Eble
- Institute for Physiological Chemistry and Pathobiochemistry, University of Münster, Münster, Germany
| | - Cezary Marcinkiewicz
- Department of Bioengineering, College of Engineering, Temple University, Philadelphia, PA, USA
| | - David Varon
- Department of Hematology, Coagulation Unit, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Philip Lazarovici
- School of Pharmacy Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| |
Collapse
|
7
|
Momic T, Cohen G, Reich R, Arlinghaus FT, Eble JA, Marcinkiewicz C, Lazarovici P. Vixapatin (VP12), a c-type lectin-protein from Vipera xantina palestinae venom: characterization as a novel anti-angiogenic compound. Toxins (Basel) 2012; 4:862-77. [PMID: 23162702 PMCID: PMC3496993 DOI: 10.3390/toxins4100862] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 09/29/2012] [Accepted: 10/08/2012] [Indexed: 12/30/2022] Open
Abstract
A C-type lectin-like protein (CTL), originally identified as VP12 and lately named Vixapatin, was isolated and characterized from Israeli viper Vipera xantina palestinae snake venom. This CTL was characterized as a selective α2β1 integrin inhibitor with anti-melanoma metastatic activity. The major aim of the present study was to prove the possibility that this protein is also a potent novel anti-angiogenic compound. Using an adhesion assay, we demonstrated that Vixapatin selectively and potently inhibited the α2 mediated adhesion of K562 over-expressing cells, with IC(50) of 3 nM. 3 nM Vixapatin blocked proliferation of human dermal microvascular endothelial cells (HDMEC); 25 nM inhibited collagen I induced migration of human fibrosarcoma HT-1080 cells; and 50 nM rat C6 glioma and human breast carcinoma MDA-MB-231 cells. 1 µM Vixapatin reduced HDMEC tube formation by 75% in a Matrigel assay. Furthermore, 1 µM Vixapatin decreased by 70% bFGF-induced physiological angiogenesis, and by 94% C6 glioma-induced pathological angiogenesis, in shell-less embryonic quail chorioallantoic membrane assay. Vixapatin's ability to inhibit all steps of the angiogenesis process suggest that it is a novel pharmacological tool for studying α2β1 integrin mediated angiogenesis and a lead compound for the development of a novel anti-angiogenic/angiostatic/anti-cancer drug.
Collapse
Affiliation(s)
- Tatjana Momic
- School of Pharmacy, Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel; (T.M.); (G.C.); (R.R.)
| | - Gadi Cohen
- School of Pharmacy, Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel; (T.M.); (G.C.); (R.R.)
| | - Reuven Reich
- School of Pharmacy, Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel; (T.M.); (G.C.); (R.R.)
| | - Franziska T. Arlinghaus
- Center for Molecular Medicine, Department of Vascular Matrix Biology, Excellence Cluster Cardio-Pulmonary System, Frankfurt University Hospital, Frankfurt 60590, Germany; (F.T.A.); (J.A.E.)
| | - Johannes A. Eble
- Center for Molecular Medicine, Department of Vascular Matrix Biology, Excellence Cluster Cardio-Pulmonary System, Frankfurt University Hospital, Frankfurt 60590, Germany; (F.T.A.); (J.A.E.)
| | - Cezary Marcinkiewicz
- Department of Biology, Temple University College of Science and Technology; Philadelphia, PA 19122, USA;
| | - Philip Lazarovici
- School of Pharmacy, Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel; (T.M.); (G.C.); (R.R.)
| |
Collapse
|
8
|
Bazan-Socha S, Zuk J, Plutecka H, Marcinkiewicz C, Zareba L, Musial J. Collagen receptors α(1)β(1) and α(2)β(1) integrins are involved in transmigration of peripheral blood eosinophils, but not mononuclear cells through human microvascular endothelial cells monolayer. J Physiol Pharmacol 2012; 63:373-379. [PMID: 23070086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Accepted: 08/20/2012] [Indexed: 06/01/2023]
Abstract
UNLABELLED Asthma development may be driven by T helper lymphocytes with eosinophils playing the role of major effector cells. Recruitment of the inflammatory cells from blood to the airways is mediated by adhesive molecules, e.g. selectins and integrins. The most important in cell trafficking are integrins containing α(4) and β(2) subunits. We hypothesized that also collagen receptors: α(1)β(1) and α(2)β(1), may be involved in cell migration to the inflammatory site in asthma. The aim of the study was to determine whether the inhibition of α(1)β(1) or α(2)β(1) integrins, affects transmigration of eosinophils and peripheral blood mononuclear cells (PBMC) through human microvascular endothelial cells monolayer (HMVEC) seeded on collagen IV coated wells in moderate persistent atopic asthmatics. METHODS PBMC from 9 asthmatics were separated by gradient centrifugation followed by negative magnetic separation of eosinophils. Snake venom derived anti-adhesive proteins: viperistatin and VP12 (potent and selective inhibitors of α(1)β(1) and α(2)β(1) integrins, respectively) as well as VLO4 (a non-selective inhibitor of α(4)β(1), α(5)β(1) and α(v)β(3) - used as a positive control), were used for inhibition studies. All anti-adhesive proteins studied, inhibited eosinophils, but only VLO4 affected PBMC transmigration through HMVEC. In bronchial asthma both collagen receptors α(1)β(1) and α(2)β(1) are likely to be involved in eosinophil transmigration to the inflammatory site. The role of α(2)β(1) on lymphocytes is probably different. As the α(2)β(1) integrin has been described as a stimulator of collagen accumulation, it might be, at least in part, responsible for asthma airway remodelling.
Collapse
Affiliation(s)
- S Bazan-Socha
- Second Department of Internal Medicine, Unit of Allergy and Clinical Immunology, Jagiellonian University Medical College, Cracow Poland.
| | | | | | | | | | | |
Collapse
|
9
|
Abstract
At sites of vascular injury, collagen-mediated platelet adhesion and activation have long been known as one of the first events in platelet-dependent thrombus formation. Studying patients with bleeding disorders that are caused by defective platelet adhesion to collagen resulted in the identification of several platelet collagen receptors, with glycoprotein VI and integrin α2β1 being the most important ones. Subsequent development of specific collagen receptor knockout mice and various inhibitors of platelet binding to collagen have further proven the role of these receptors in haemostasis and thrombosis. The search for clinically applicable inhibitors for use as antithrombotic drug has led to the identification of inhibitory antibodies, soluble receptor fragments, peptides, collagen-mimetics and proteins from snake venoms or haematophagous animals. In experimental settings, these inhibitors have a good antithrombotic effect, with little prolongation of bleeding times, suggesting a larger therapeutic window than currently available antiplatelet drugs. However, at present, none of the collagen receptor blockers are in clinical development yet.
Collapse
Affiliation(s)
- Hans Deckmyn
- Laboratory for Thrombosis Research, KU Leuven campus Kortrijk, Kortrijk, Belgium.
| | | | | | | |
Collapse
|
10
|
Goyal A, Pal N, Concannon M, Paul M, Doran M, Poluzzi C, Sekiguchi K, Whitelock JM, Neill T, Iozzo RV. Endorepellin, the angiostatic module of perlecan, interacts with both the α2β1 integrin and vascular endothelial growth factor receptor 2 (VEGFR2): a dual receptor antagonism. J Biol Chem 2011; 286:25947-62. [PMID: 21596751 PMCID: PMC3138248 DOI: 10.1074/jbc.m111.243626] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Revised: 05/04/2011] [Indexed: 12/21/2022] Open
Abstract
Endorepellin, the C-terminal module of perlecan, negatively regulates angiogenesis counter to its proangiogenic parental molecule. Endorepellin (the C-terminal domain V of perlecan) binds the α2β1 integrin on endothelial cells and triggers a signaling cascade that leads to disruption of the actin cytoskeleton. Here, we show that both perlecan and endorepellin bind directly and with high affinity to both VEGF receptors 1 and 2, in a region that differs from VEGFA-binding site. In both human and porcine endothelial cells, this interaction evokes a physical down-regulation of both the α2β1 integrin and VEGFR2, with concurrent activation of the tyrosine phosphatase SHP-1 and downstream attenuation of VEGFA transcription. We demonstrate that endorepellin requires both the α2β1 integrin and VEGFR2 for its angiostatic activity. Endothelial cells that express α2β1 integrin but lack VEGFR2, do not respond to endorepellin treatment. Thus, we provide a new paradigm for the activity of an antiangiogenic protein and mechanistically explain the specificity of endorepellin for endothelial cells, the only cells that simultaneously express both receptors. We hypothesize that a mechanism such as dual receptor antagonism could operate for other angiostatic fragments.
Collapse
Affiliation(s)
- Atul Goyal
- From the Department of Pathology, Anatomy, and Cell Biology, and the Cancer Cell Biology and Signaling Program, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Nutan Pal
- From the Department of Pathology, Anatomy, and Cell Biology, and the Cancer Cell Biology and Signaling Program, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Matthew Concannon
- From the Department of Pathology, Anatomy, and Cell Biology, and the Cancer Cell Biology and Signaling Program, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Matthew Paul
- From the Department of Pathology, Anatomy, and Cell Biology, and the Cancer Cell Biology and Signaling Program, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Mike Doran
- From the Department of Pathology, Anatomy, and Cell Biology, and the Cancer Cell Biology and Signaling Program, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Chiara Poluzzi
- From the Department of Pathology, Anatomy, and Cell Biology, and the Cancer Cell Biology and Signaling Program, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Kiyotoshi Sekiguchi
- the Laboratory of Extracellular Matrix Biochemistry, Institute for Protein Research, Osaka University, Osaka 565-0871, Japan, and
| | - John M. Whitelock
- the Graduate School of Biomedical Engineering, University of New South Wales, Sydney 2052, Australia
| | - Thomas Neill
- From the Department of Pathology, Anatomy, and Cell Biology, and the Cancer Cell Biology and Signaling Program, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Renato V. Iozzo
- From the Department of Pathology, Anatomy, and Cell Biology, and the Cancer Cell Biology and Signaling Program, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| |
Collapse
|
11
|
Zhu P, Yang C, Chen LH, Ren M, Lao GJ, Yan L. Impairment of human keratinocyte mobility and proliferation by advanced glycation end products-modified BSA. Arch Dermatol Res 2010; 303:339-50. [PMID: 21132435 DOI: 10.1007/s00403-010-1102-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Revised: 11/16/2010] [Accepted: 11/22/2010] [Indexed: 11/26/2022]
Abstract
The migration and proliferation of keratinocytes is critical to wound re-epithelialization and defects in this function are associated with the clinical phenomenon of chronic non-healing wounds. Advanced glycation end products (AGEs) occur through non-enzymatic glycation of long-lived proteins in diabetes and play important roles in diabetic complications. However, specific roles for AGEs in keratinocyte migration and proliferation, and the underlying molecular mechanisms, have not been fully established. The aim of the current study was to elucidate the interaction between AGE-modified bovine serum albumin (AGE-BSA) and keratinocytes. As a result, we found that AGE-BSA had no effect on the viability of keratinocytes for up to 48 h of incubation with 50 μg/ml of AGE-BSA. AGE-BSA (but not non-glycated BSA) exerted a concentration-dependent suppression of keratinocyte migration at a range of concentrations. The expression of matrix metalloproteinase-9 (MMP-9) was significantly up-regulated in keratinocytes incubated with increasing AGE-BSA, but tissue inhibitor of metalloproteinases-1 (TIMP-1) expression was down-regulated. AGE-BSA also profoundly depressed phospho-focal adhesion kinase-Tyr397 (p-FAK) and α2β1 integrin expression, while total-FAK expression levels remained constant, in keratinocytes. The proliferative capacity of keratinocytes was diminished after 72 h AGE-BSA incubation. Taken together, these findings suggested that in the presence of AGE-BSA, keratinocytes lose their migratory and proliferation abilities. These data also indicated that, in the context of the chronic hyperglycemia in diabetes, the effects of AGE-BSA on keratinocyte migration might be mediated through MMP-9/TIMP-1, p-FAK and α2β1 integrin.
Collapse
Affiliation(s)
- Ping Zhu
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China
| | | | | | | | | | | |
Collapse
|
12
|
Abstract
Interactions between the integrin, alpha2beta1, and extracellular matrix (ECM), particularly collagen, play a pivotal role in platelet adhesion and thrombus formation. Platelets interact with collagen in the subendothelial matrix that is exposed by vascular damage. To evaluate the potential of alpha2beta1 inhibitors for anticancer and antithrombotic applications, we have developed a series of small molecule inhibitors of this integrin based on a prolyl-2,3-diaminopropionic acid (DAP) scaffold using solid-phase parallel synthesis. A benzenesulfonamide substituent at the N-terminus of the dipepetide and a benzyl urea at the DAP side chain resulted in tight and highly selective inhibition of alpha2beta1-mediated adhesion of human platelets and other cells to collagen.
Collapse
|
13
|
Lin MT, Chang CC, Lin BR, Yang HY, Chu CY, Wu MH, Kuo ML. Elevated expression of Cyr61 enhances peritoneal dissemination of gastric cancer cells through integrin alpha2beta1. J Biol Chem 2007; 282:34594-604. [PMID: 17905740 DOI: 10.1074/jbc.m706600200] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Cysteine-rich 61 (Cyr61/CCN1) is involved in human gastric cancer development and progression. Nonetheless, the role of Cyr61 as regards peritoneal dissemination of such cancers has not yet been completely characterized. We used liposome-mediated transfection to establish Cyr61, or antisense Cyr61, expression vectors into gastric cancer AGS or MKN45 cell lines. Transfectants were tested by means of a cancer-cell adhesion assay in vitro and ex vivo. Furthermore, a functional integrin fluorescence-activated cell sorting assay, reverse transcription-PCR, and an AP-1 reporter assay were performed to investigate the potential signaling pathway of Cyr61. It was shown that stable transfection of Cyr61 into the AGS cell line strongly enhanced its adhesion ability. The overexpression of Cyr61 within AGS cells significantly increased the functional expression of integrin alpha(2)beta(1). Function-neutralizing antibody to integrin alpha(2)beta(1) effectively suppressed the Cyr61-mediated enhanced adhesion of AGS cells to peritoneal tissue. Promoter assays of integrin alpha2 gene further revealed that the AP-1 pathway was evidently activated within Cyr61-expressing AGS cells. Animal studies have revealed that mice injected with Cyr61-overexpressed AGS cells featured a greater number of peritoneal seeding nodules and a lower survival rate than the Neo control cell lines, and when such cells were treated with functional blocking antibody to integrin alpha(2)beta(1), they were able to elicit a decline in the peritoneal dissemination. The data suggest that Cyr61 may contribute to the peritoneal dissemination of gastric cancer by promoting tumor-cell adhesion ability through the up-regulation of the functional integrin alpha(2)beta(1) via an AP-1-dependent pathway.
Collapse
Affiliation(s)
- Ming-Tsan Lin
- Department of Primary Care Medicine, National Taiwan University Hospital, Taipei 100, Taiwan
| | | | | | | | | | | | | |
Collapse
|
14
|
Abstract
Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS). Adhesion molecules play important roles in cell-cell and cell-extracellular matrix (ECM) interactions in inflammation. Blocking the interaction between inflammatory cells and vascular endothelia can prevent cell entry into tissues and harmful inflammatory responses, that is, autoimmunity, but could also limit immunosurveillance by anti-viral T cells in sites of infection or latency. Development of progressive multifocal leukoencephalopathy in patients treated with antibody against very late antigen (VLA)-4 prompted us to explore an alternative therapeutic approach. We used an antibody against the integrin alpha2, VLA-2, that interacts with ECM, not vascular endothelium. SJL/J mice were sensitized with myelin proteolipid protein (PLP)(139-151) peptide to induce experimental autoimmune encephalomyelitis (EAE), an animal model for MS. Treatment of mice with VLA-2 antibody suppressed clinical signs and CNS inflammation of EAE, when antibody was given immediately after disease onset. In contrast, VLA-4 or VLA-2 antibody treatment of mice during the priming or remission phase of EAE had minor effects on the disease's clinical course. No differences were found in lymphoproliferative responses to PLP(139-151) among treatment groups. Data suggest that blocking cell-ECM interactions can be an alternative therapy for MS.
Collapse
Affiliation(s)
- Ikuo Tsunoda
- Department of Neurology, University of Utah School of Medicine, Salt Lake City, Utah
| | - Emily Jane Terry
- Department of Neurology, University of Utah School of Medicine, Salt Lake City, Utah
| | - Benjamin J. Marble
- Department of Neurology, University of Utah School of Medicine, Salt Lake City, Utah
| | - Elias Lazarides
- (Formerly of Targeted Molecules Corporation) Chromos Molecular Systems, Burnaby, British Columbia, Canada
| | - Catherine Woods
- (Formerly of Targeted Molecules Corporation) Chromos Molecular Systems, Burnaby, British Columbia, Canada
| | - Robert S. Fujinami
- Department of Neurology, University of Utah School of Medicine, Salt Lake City, Utah
| |
Collapse
|
15
|
White TC, Berny MA, Robinson DK, Yin H, DeGrado WF, Hanson SR, McCarty OJT. The leech product saratin is a potent inhibitor of platelet integrin α2β1 and von Willebrand factor binding to collagen. FEBS J 2007; 274:1481-91. [PMID: 17489103 DOI: 10.1111/j.1742-4658.2007.05689.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Subendothelial collagen plays an important role, via both direct and indirect mechanisms, in the initiation of thrombus formation at sites of vascular injury. Collagen binds plasma von Willebrand factor, which mediates platelet recruitment to collagen under high shear. Subsequently, the direct binding of the platelet receptors glycoprotein VI and alpha2beta1 to collagen is critical for platelet activation and stable adhesion. Leeches, have evolved a number of inhibitors directed towards platelet-collagen interactions so as to prevent hemostasis in the host during hematophagy. In this article, we describe the molecular mechanisms underlying the ability of the leech product saratin to inhibit platelet binding to collagen. In the presence of inhibitors of ADP and thromboxane A2, both saratin and 6F1, a blocking alpha2beta1 mAb, abrogated platelet adhesion to fibrillar and soluble collagen. Additionally, saratin eliminated alpha2beta1-dependent platelet adhesion to soluble collagen in the presence of an Src kinase inhibitor. Moreover, saratin prevented platelet-rich plasma adhesion to fibrillar collagen, a process dependent upon both alpha2beta1 and von Willebrand factor binding to collagen. Furthermore, saratin specifically inhibited the binding of the alpha2 integrin subunit I domain to collagen, and prevented platelet adhesion to collagen under flow to the same extent as observed in the presence of a combination of mAbs to glycoprotein Ib and alpha2beta1. These results demonstrate that saratin interferes with integrin alpha2beta1 binding to collagen in addition to inhibiting von Willebrand factor-collagen binding, presumably by binding to an overlapping epitope on collagen. This has significant implications for the use of saratin as a tool to inhibit platelet-collagen interactions.
Collapse
Affiliation(s)
- Tara C White
- Department of Biomedical Engineering, Oregon Health & Science University, 13B-CHH, 3303 SW Bond Avenue, Portland, OR 97239, USA
| | | | | | | | | | | | | |
Collapse
|
16
|
Yin H, Gerlach LO, Miller MW, Moore DT, Liu D, Vilaire G, Bennett JS, DeGrado WF. Arylamide derivatives as allosteric inhibitors of the integrin alpha2beta1/type I collagen interaction. Bioorg Med Chem Lett 2006; 16:3380-2. [PMID: 16678410 DOI: 10.1016/j.bmcl.2006.04.037] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2006] [Accepted: 04/05/2006] [Indexed: 11/24/2022]
Abstract
We herein report a group of allosteric inhibitors of integrin alpha(2)beta(1) based on an arylamide scaffold. Compound 4 showed an IC(50) of 4.80 microM in disrupting integrin I-domain/collagen binding in an ELISA. These arylamide compounds are able to block collagen binding to integrin alpha(2)beta(1) on the platelet surface. Further we find that compound 4 recognizes a hydrophobic cleft on the side of the alpha(2) I-domain, suggesting an alternative targeting site for drug development.
Collapse
Affiliation(s)
- Hang Yin
- Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, 19104, USA
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Wang CZ, Su HW, Hsu YC, Shen MR, Tang MJ. A discoidin domain receptor 1/SHP-2 signaling complex inhibits alpha2beta1-integrin-mediated signal transducers and activators of transcription 1/3 activation and cell migration. Mol Biol Cell 2006; 17:2839-52. [PMID: 16611743 PMCID: PMC1474786 DOI: 10.1091/mbc.e05-11-1068] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Regulation of cell migration is an important step for the development of branching tubule morphogenesis in collagen gel. Here, we showed that discoidin domain receptor (DDR) 1a/b inhibited collagen-induced tyrosine phosphorylation of signal transducers and activators of transcription (Stat) 1/3 and cell migration triggered by alpha2beta1-integrin. Overexpression of DDR1a/b increased the interaction of DDR1 with SHP-2 and up-regulated the tyrosine phosphatase activity of SHP-2. Expression of catalytically inactive SHP-2 in DDR1-transfected cells restored the tyrosine phosphorylation of Stat3 and cell migration. We demonstrated that the Src homology-2 (SH2)-SH2 and phosphotyrosyl phosphatase (PTP) domains of SHP-2 were responsible for interaction with DDR1 and that both tyrosine phosphorylation sites 703 and 796 of DDR1 were essential for it to bind with SHP-2. Mutation of tyrosine 703 or 796 of DDR1 abolished the ability of DDR1 to inhibit the tyrosine phosphorylation of Stat1 and Stat3 and restored collagen-induced cell migration and hepatocyte growth factor-induced branching tubulogenesis in collagen gel. Together, these results demonstrate that SHP-2 is required for the DDR1-induced suppression of Stat1 and Stat3 tyrosine phosphorylation, cell migration, and branching tubulogenesis.
Collapse
Affiliation(s)
- Chau-Zen Wang
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan 701, Taiwan
| | | | | | | | | |
Collapse
|
18
|
Abstract
BACKGROUND Human inflammatory bowel disease (e.g., Crohn's disease and ulcerative colitis), is associated with leukocyte accumulation in the inflamed intestinal tissue. Recent studies strongly suggest a role of beta1 integrin receptors in regulating tissue damage and disease symptoms related to inflammatory bowel disease. The aim of this study was to investigate the role of the collagen-binding alpha2beta1 integrin (CD49b/CD29) in dextran sodium sulfate-induced colitis in mice. METHODS Colitis was induced in mice through oral administration of 2% dextran sodium sulfate in drinking water. Rectal administration of anti-alpha2-monoclonal antibody (mAb) in 1 group was compared with oral treatment with betamethasone in another group and rectal administration of a control antibody in a third group. Clinical and histological signs of colitis, neutrophil infiltration into the colon mucosa, and gene expression of metalloproteinases were assessed. RESULTS Rectal administration of anti-alpha2-mAb was found to significantly reduce weight loss from 13.5% +/- 6.5% to 2.2% +/- 0.2% (P = 0.013 versus control mAb) and mucosal neutrophil infiltration from 47.2 +/- 10.0 to 6.6 +/- 8.0 neutrophils per counted area (P < 0.05 versus control mAb). Metalloproteinase gene expression was suppressed through anti-alpha2-mAb treatment. The protective effect against colitis seen after anti-alpha2beta1 integrin treatment was found to be favorable to the effect seen after high-dose oral betamethasone. CONCLUSIONS We demonstrate an alleviating action of the collagen-binding alpha2beta1 integrin in experimental colitis in mice and suggest that this effect is mediated by inhibition of neutrophil migration and activation. Local administration of function-blocking antibodies against integrin alpha2beta1 may provide novel avenues to treat inflammatory bowel disease.
Collapse
Affiliation(s)
- Sofie Lundberg
- Department of Medicine, Unit of Gastroenterology and Hepatology, Karolinska Institutet, Karolinska University Hospital, Stockholm.
| | | | | | | | | |
Collapse
|
19
|
Jung SM, Ohnuma M, Watanabe N, Sonoda M, Handa M, Moroi M. Analyzing the mechanism of Rap1 activation in platelets: Rap1 activation is related to the release reaction mediated through the collagen receptor GPVI. Thromb Res 2006; 118:509-21. [PMID: 16380154 DOI: 10.1016/j.thromres.2005.11.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2005] [Revised: 10/05/2005] [Accepted: 11/05/2005] [Indexed: 10/25/2022]
Abstract
The abundant Rap1 in platelets becomes activated when these cells are stimulated by various agonists, but its function has remained unknown. In view of this, we developed an assay to quantitatively measure activated Rap1 and used it to determine relationships between Rap1 activation and several platelet functions: integrin alpha2beta1 activation, tyrosine phosphorylation, and the release reaction. We looked at how these processes are affected by the protein kinase C inhibitor BIMI, tyrosine kinase inhibitor PP2, PI 3-kinase inhibitor wortmannin, and ADP scavenger apyrase. In CRP (collagen related peptide)-activated platelets, all the inhibitors severely inhibited Rap1 activation, but had little effect on integrin alpha2beta1 activation, indicating that the integrin activation mechanism is different from the Rap1 activation mechanism, at least in GPVI-dependent activation. With p85alpha-null mouse platelets, we demonstrated that Rap1 activation involves PI 3-kinase p85alpha-dependent tyrosine phosphorylation. All the inhibitors similarly decreased Rap1 activation and the serotonin release reaction, and the inhibition of Rap1 activation was not due to the lack of released ADP. Our results indicate that platelet Rap1 activation is closely related to the release reaction and not to integrin alpha2beta1 activation in GPVI-mediated platelet activation.
Collapse
Affiliation(s)
- Stephanie M Jung
- Department of Protein Biochemistry, Institute of Life Science, Kurume University, Kurume, Fukuoka, Japan
| | | | | | | | | | | |
Collapse
|
20
|
Abstract
Collagen and collagen-related peptide (CRP) activate platelets by interacting with glycoprotein (GP)VI. In addition, collagen binds to integrin alpha2beta1 and possibly to other receptors. In this study, we have compared the role of integrins alpha2beta1 and alphaIIbbeta3 in platelet activation induced by collagen and CRP. Inhibitors of ADP and thromboxane A2 (TxA2) substantially attenuated collagen-induced platelet aggregation and dense granule release, whereas CRP-induced responses were only partially inhibited. Under these conditions, a proportion of platelets adhered to the collagen fibres resulting in dense granule release and alphaIIbbeta3 activation. This adhesion was substantially mediated by alpha2beta1. The alphaIIbbeta3 antagonist lotrafiban potentiated CRP-induced dense granule release, suggesting that alphaIIbbeta3 outside-in signalling may attenuate GPVI signals. By contrast, lotrafiban inhibited collagen-induced dense granule release. These results emphasise the differential roles of alpha2beta1 and alphaIIbbeta3 in platelet activation induced by collagen and CRP. Further, they show that although ADP and TxA2 greatly facilitate collagen-induced platelet activation, collagen can induce full activation of those platelets to which it binds in the absence of these mediators, via a mechanism that is dependent on adhesion to alpha2beta1.
Collapse
|
21
|
Horii K, Okuda D, Morita T, Mizuno H. Crystal Structure of EMS16 in Complex with the Integrin α2-I Domain. J Mol Biol 2004; 341:519-27. [PMID: 15276841 DOI: 10.1016/j.jmb.2004.06.036] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2004] [Revised: 06/03/2004] [Accepted: 06/03/2004] [Indexed: 10/26/2022]
Abstract
Snake venoms contain a number of heterodimeric C-type lectin-like proteins (CLPs) that interact specifically with components of the haemostatic system. EMS16 from the venom of Echis multisquamatus binds to the collagen receptor, integrin alpha2beta1, also known as glycoprotein (GP) Ia/IIa, and specifically inhibits collagen binding. Here we report the crystal structure of EMS16 in complex with recombinant integrin alpha2-I domain that plays a central role in collagen binding. The structure of the complex at 1.9 Angstrom resolution reveals that the collagen-binding site of the alpha2-I domain is covered completely by the bound EMS16. This blockage by EMS16 appears to spatially inhibit collagen binding to the alpha2-I domain. The bound alpha2-I domain adopts a closed conformation, which is seen in the absence of ligand, suggesting that EMS16 stabilizes a closed conformation corresponding to the less active structure of the alpha2-I domain. EMS16 does not directly bind to the manganese ion and residues of the metal ion-dependent adhesion site (MIDAS) of the alpha2-I domain, suggesting that EMS16 may have the potential to bind specifically to the alpha2-I domain in a metal ion-independent fashion.
Collapse
Affiliation(s)
- Katsunori Horii
- Department of Biochemistry, National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan
| | | | | | | |
Collapse
|
22
|
Abstract
BACKGROUND Periodontal ligament (PDL) cells form mineralized nodules in vitro. Ascorbic acid is known to be required in this process, although its effect on osteoblastic differentiation of PDL cells remains unclear. The purpose of this study was to determine the role of ascorbic acid on the early osteoblastic differentiation of PDL cells, with regard to alkaline phosphatase (ALP) activity, type I collagen production and integrin expression. METHODS Cultured PDL cells were stimulated at confluence with ascorbic acid in the presence or absence of type I collagen inhibitor and blocking antibodies to integrins. After stimulation, the cells and culture supernatants were examined for ALP activity, type I collagen production, and integrin expression. The ALP activity was measured using a colorimetric assay with p-nitrophenyl phosphate and ALP staining. Enzyme-linked immunosorbent assay (ELISA) was used to determine type I collagen production, and ELISA and flow cytometric analysis were employed for assessment of integrin expression. RESULTS Both ALP activity and type I collagen production were upregulated when PDL cells were cultured in the presence of ascorbic acid (200 microM). Inhibitor of the formation of collagen triple helices and blocking antibodies to alpha2beta1 integrin inhibited ALP activity by 50% in ascorbic acid-stimulated PDL cells. Furthermore, ascorbic acid increased the cell surface expression of alpha2beta1 integrin. CONCLUSIONS Our findings indicated that ascorbic acid increases the ALP activity of PDL cells via type I collagen production and also enhances the expression of alpha2beta1 integrin, which is a major receptor of type I collagen. These results suggest that ascorbic acid promotes the osteoblastic differentiation of PDL cells by modulating type I collagen-alpha2beta1 integrin interaction.
Collapse
Affiliation(s)
- Satoshi Ishikawa
- Section of Periodontology, Dept of Hard Tissue Engineering, Graduate School, Center of Excellence Program for Frontier Research on Molecular Destruction and Reconstruction of Tooth and Bone, Tokyo Medical and Dental University, Japan.
| | | | | | | |
Collapse
|
23
|
Sanders MA, Basson MD. Collagen IV regulates Caco-2 migration and ERK activation via alpha1beta1- and alpha2beta1-integrin-dependent Src kinase activation. Am J Physiol Gastrointest Liver Physiol 2004; 286:G547-57. [PMID: 14604860 DOI: 10.1152/ajpgi.00262.2003] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Our previous work indicates intestinal epithelial cell ERK activation by collagen IV, a major component of the intestinal epithelial basement membrane, requires focal adhesion kinase (FAK) and suggests FAK and ERK may have important roles in regulating intestinal epithelial cell migration. We therefore sought to identify FAK downstream targets regulating intestinal epithelial cell spreading, migration, and ERK activation on collagen IV and the integrins involved. Both dominant-negative Src and Src inhibitor PP2 strongly inhibited collagen IV ERK activation in Caco-2 intestinal epithelial cells. Collagen IV stimulated Grb2 binding site FAK Y925 phosphorylation, which was inhibited by PP2 and required FAK Y397 autophosphorylation. Additionally, FAK Y925F expression blocked collagen IV ERK activation. alpha(1)beta(1)- Or alpha(2)beta(1)-integrin blockade with alpha(1)- or alpha(2)-integrin subunit antibodies indicated that either integrin can mediate adhesion, cell spreading, and FAK, Src, and ERK activation on collagen IV. Both dominant-negative Src and PP2 inhibited Caco-2 spreading on collagen IV. PP2 inhibited p130(Cas) tyrosine phosphorylation, but dominant-negative p130(Cas) did not inhibit cell spreading. PP2 inhibited Caco-2 migration on collagen IV much more strongly than the mitogen-activated protein kinase kinase inhibitor PD-98059, which completely inhibited collagen IV ERK activation. These results suggest a pathway for collagen IV ERK activation requiring Src phosphorylation of FAK Y925 not previously described for this matrix protein and suggest either alpha(1)beta(1)- or alpha(2)beta(1)-integrins can regulate Caco-2 spreading and ERK activation on collagen IV via Src. Additionally, these results suggest Src regulates Caco-2 migration on collagen IV primarily through ERK-independent pathways.
Collapse
Affiliation(s)
- Matthew A Sanders
- Department of Surgery, Wayne State University, Detroit, MI 48201-1932, USA
| | | |
Collapse
|
24
|
Siljander PRM, Munnix ICA, Smethurst PA, Deckmyn H, Lindhout T, Ouwehand WH, Farndale RW, Heemskerk JWM. Platelet receptor interplay regulates collagen-induced thrombus formation in flowing human blood. Blood 2004; 103:1333-41. [PMID: 14563646 DOI: 10.1182/blood-2003-03-0889] [Citation(s) in RCA: 145] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractThe platelet glycoproteins (GPs) Ib, integrin α2β1, and GPVI are considered central to thrombus formation. Recently, their relative importance has been re-evaluated based on data from murine knockout models. To examine their relationship during human thrombus formation on collagen type I fibers at high shear (1000 s–1), we tested a novel antibody against GPVI, an immunoglobulin single-chain variable fragment, 10B12, together with specific antagonists for GPIbα (12G1 Fab2) and α2β1 (6F1 mAb or GFOGER-GPP peptide). GPVI was found to be crucial for aggregate formation, Ca2+ signaling, and phosphatidylserine (PS) exposure, but not for primary adhesion, even with more than 97% receptor blockade. Inhibiting α2β1 revealed its involvement in regulating Ca2+ signaling, PS exposure, and aggregate size. Both GPIbα and α2β1 contributed to primary adhesion, showing overlapping function. The coinhibition of receptors revealed synergism in thrombus formation: the coinhibition of adenosine diphosphate (ADP) receptors with collagen receptors further decreased adhesion and aggregation, and, crucially, the complete eradication of thrombus formation required the coinhibition of GPVI with either GPIbα or α2β1. In summary, human platelet deposition on collagen depends on the concerted interplay of several receptors: GPIb in synergy with α2β1 mediating primary adhesion, reinforced by activation through GPVI, which further regulates the thrombus formation.
Collapse
Affiliation(s)
- Pia R-M Siljander
- Department of Biochemistry, University of Cambridge, Main Bldg, Downing Site, Tennis Court Rd, CB2 1QW Cambridge, United Kingdom.
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Khalsa PS, Ge W, Uddin MZ, Hadjiargyrou M. Integrin α2β1 affects mechano-transduction in slowly and rapidly adapting cutaneous mechanoreceptors in rat hairy skin. Neuroscience 2004; 129:447-59. [PMID: 15501602 DOI: 10.1016/j.neuroscience.2004.08.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/04/2004] [Indexed: 10/26/2022]
Abstract
The role of a transmembrane protein, integrin alpha2beta1, to modulate the neural responses of cutaneous mechanoreceptors to mechanical indentation was examined using an isolated skin-nerve preparation in a rat model. Skin and its intact innervation were harvested from the medial thigh of the hindlimb and placed in a dish containing synthetic interstitial fluid. Using a standard teased nerve preparation, the neural responses of single slowly or rapidly adapting mechanoreceptors (SA or RA, respectively) were identified and the afferents categorized according to standard protocols (i.e. response to constant stimuli). The most sensitive spot of a mechanoreceptor's receptive field was identified and then stimulated using controlled compressive stress (constant or dynamic loads between threshold and saturation load for SAs and RAs, respectively). Loads were applied before, during, and after passive diffusion into the skin of a function-blocking anti-integrin alpha2 monoclonal antibody (FBmAb) or one of two types of control antibodies (immunoglobulin G or a FBmAb conjugated with a secondary antibody). The sensitivities of both SA and RA mechanoreceptors were profoundly reduced in the presence of the FBmAb, while not changing the waveforms of their action potentials or their adaptation properties. Both control antibodies had no significant effect on mechanoreceptors' sensitivities. Following removal of the FBmAb, the effects in some neurons were partially reversible. Taken together, the data from this study support the hypothesis that integrin alpha2beta1 plays a significant role in modulating mechanoreceptive response to compressive indentation.
Collapse
Affiliation(s)
- P S Khalsa
- Department of Biomedical Engineering, State University of New York, HSC T18-031, Stony Brook, NY 11794-8181, USA.
| | | | | | | |
Collapse
|
26
|
Conant K, St Hillaire C, Nagase H, Visse R, Gary D, Haughey N, Anderson C, Turchan J, Nath A. Matrix metalloproteinase 1 interacts with neuronal integrins and stimulates dephosphorylation of Akt. J Biol Chem 2003; 279:8056-62. [PMID: 14679206 DOI: 10.1074/jbc.m307051200] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Several studies have demonstrated that matrix metalloproteinases (MMPs) are cytotoxic. The responsible mechanisms, however, are not well understood. MMPs may promote cytotoxicity through their ability to disrupt or degrade matrix proteins that support cell survival, and MMPs may also cleave substrates to generate molecules that stimulate cell death. In addition, MMPs may themselves act on cell surface receptors that affect cell survival. Among such receptors is the alpha(2)beta(1) integrin, a complex that has previously been linked to leukocyte death. In the present study we show that human neurons express alpha(2)beta(1) and that pro-MMP-1 interacts with this integrin complex. We also show that stimulation of neuronal cultures with MMP-1 is associated with a rapid reduction in the phosphorylation of Akt, a kinase that can influence caspase activity and cell survival. Moreover, MMP-1-associated dephosphorylation of Akt is inhibited by a blocking antibody to the alpha(2) integrin, but not by batimastat, an inhibitor of MMP-1 enzymatic activity. Such dephosphorylation is also stimulated by a catalytic mutant of pro-MMP-1. Additional studies show that MMP-1 causes neuronal death, which is significantly diminished by both a general caspase inhibitor and anti-alpha(2) but not by batimastat. Together, these results suggest that MMP-1 can stimulate dephosphorylation of Akt and neuronal death through a non-proteolytic mechanism that involves changes in integrin signaling.
Collapse
Affiliation(s)
- Katherine Conant
- Departments of Neurology and Neuropathology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Eble JA, Tuckwell DS. The alpha2beta1 integrin inhibitor rhodocetin binds to the A-domain of the integrin alpha2 subunit proximal to the collagen-binding site. Biochem J 2003; 376:77-85. [PMID: 12871211 PMCID: PMC1223739 DOI: 10.1042/bj20030373] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2003] [Revised: 06/25/2003] [Accepted: 07/21/2003] [Indexed: 11/17/2022]
Abstract
Rhodocetin is a snake venom protein that binds to alpha2beta1 integrin, inhibiting its interaction with its endogenous ligand collagen. We have determined the mechanism by which rhodocetin inhibits the function of alpha2beta1. The interaction of alpha2beta1 with collagen and rhodocetin differed: Ca(2+) ions and slightly acidic pH values increased the binding of alpha2beta1 integrin to rhodocetin in contrast with their attenuating effect on collagen binding, suggesting that rhodocetin preferentially binds to a less active conformation of alpha2beta1 integrin. The alpha2A-domain [von Willebrand factor domain A homology domain (A-domain) of the integrin alpha2 subunit] is the major site for collagen binding to alpha2beta1. Recombinant alpha2A-domain bound rhodocetin, demonstrating that the A-domain is also the rhodocetin-binding domain. Although the interaction of alpha2beta1 with rhodocetin is affected by altering divalent cations, the interaction of the A-domain was divalent-cation-independent. The rhodocetin-binding site on the alpha2A-domain was mapped first by identifying an anti-alpha2 antibody that blocked rhodocetin binding and then mapping the epitope of the antibody using human-mouse alpha2A-domain chimaeras; and secondly, by binding studies with alpha2A-domain, which bear point mutations in the vicinity of the mapped epitope. In this way, the rhodocetin-binding site was identified as the alpha3-alpha4 loop plus adjacent alpha-helices. This region is known to form part of the collagen-binding site, thus attaining a mainly competitive mode of inhibition by rhodocetin.
Collapse
Affiliation(s)
- Johannes A Eble
- Institute of Physiological Chemistry and Pathobiochemistry, Münster University Hospital, Waldeyerstr. 15, 48149 Münster, Germany.
| | | |
Collapse
|
28
|
Andreasen SØ, Thomsen AR, Koteliansky VE, Novobrantseva TI, Sprague AG, de Fougerolles AR, Christensen JP. Expression and functional importance of collagen-binding integrins, alpha 1 beta 1 and alpha 2 beta 1, on virus-activated T cells. J Immunol 2003; 171:2804-11. [PMID: 12960301 DOI: 10.4049/jimmunol.171.6.2804] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Adhesive interactions are crucial to cell migration into inflammatory sites. Using murine lymphocytic choriomeningitis virus as an Ag model system, we have investigated expression and function of collagen-binding integrins, alpha(1)beta(1) and alpha(2)beta(1), on activated and memory T cells. Using this system and MHC tetramers to define Ag-specific T cells, we demonstrate that contrary to being VLAs, expression of alpha(1)beta(1) and alpha(2)beta(1) can be rapidly induced on acutely activated T cells, that expression of alpha(1)beta(1) remains elevated on memory T cells, and that expression of alpha(1)beta(1) parallels that of viral-specific effector CD8(+) T cells (defined by tetramer and IFN-gamma staining). In an adoptive transfer model, mAb-mediated blockade of these integrins on activated effector and memory T cells inhibited Ag-specific delayed-type hypersensitivity responses; similar decreased responses were seen upon transfer of alpha(1)-deficient activated/memory T cells. Thus, expression of alpha(1)beta(1) and alpha(2)beta(1) integrins on activated T cells is directly functionally important for generation of inflammatory responses within tissues. Finally, the inhibitory effect of alpha(1)beta(1) blockade on the delayed-type hypersensitivity response could be bypassed by direct injection of Ag-specific T cells to inflammatory sites, demonstrating for the first time in vivo that collagen-binding integrins are involved in leukocyte migration into tissues.
Collapse
Affiliation(s)
- Susanne Ø Andreasen
- Institute of Medical Microbiology and Immunology, Panum Institute, Copenhagen, Denmark. Biogen, Cambridge, MA 02142, USA
| | | | | | | | | | | | | |
Collapse
|
29
|
Suzuki-Inoue K, Inoue O, Frampton J, Watson SP. Murine GPVI stimulates weak integrin activation in PLCgamma2-/- platelets: involvement of PLCgamma1 and PI3-kinase. Blood 2003; 102:1367-73. [PMID: 12730118 DOI: 10.1182/blood-2003-01-0029] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Collagen stimulates platelet activation through a tyrosine kinase-based pathway downstream of the glycoprotein VI (GPVI)-Fc receptor (FcR) gamma-chain complex. Genetic ablation of FcR gamma-chain results in a complete inhibition of aggregation to collagen. In contrast, a steady increase in light transmission is induced by collagen in phospholipase Cgamma2-deficient (PLCgamma2-/-) platelets in a Born aggregometer, indicating a weak level of activation. This increase is inhibited partially in the presence of an alpha2beta1-blocking antibody or an alphaIIbbeta3 antagonist and completely by a combination of the 2 inhibitors. It is also abolished by the Src kinase inhibitor PP1 and reduced in the presence of the phosphatidylinositol (PI) 3-kinase inhibitor wortmannin. The GPVI-specific agonists convulxin and collagen-related peptide (CRP) also stimulate weak aggregation in PLCgamma2-/- platelets, which is inhibited by wortmannin and PP1. Collagen and CRP stimulate tyrosine phosphorylation of PLCgamma1 at its regulatory site, Tyr 783, in murine but not in human platelets through a Src kinase-dependent pathway. Adhesion of PLCgamma2-/- platelets to a collagen monolayer is severely reduced at a shear rate of 800 s-1, relative to controls, whereas it is abolished in FcR gamma-chain-/- platelets. These results provide strong evidence that engagement of GPVI stimulates limited integrin activation in PLCgamma2-/- platelets via PLCgamma1 and PI3-kinase.
Collapse
|
30
|
Yamanaka I, Koizumi M, Baba T, Yamashita S, Suzuki T, Kudo R. Epidermal growth factor increased the expression of alpha2beta1-integrin and modulated integrin-mediated signaling in human cervical adenocarcinoma cells. Exp Cell Res 2003; 286:165-74. [PMID: 12749846 DOI: 10.1016/s0014-4827(03)00065-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Epidermal growth factor (EGF) receptor (EGFR) is involved in various basic biochemical pathways and is thus thought to play an important role in cell migration. We examined the effect of EGF on motility, migration, and morphology of a human adenocarcinoma cell line CAC-1. EGF treatment increased the motility of cervical adenocarcinoma cells and promoted migration of the cells on fibronectin and type IV collagen. EGF induced morphological changes with lamellipodia during EGFR-mediated motility. The results of an immunoprecipitation study showed that EGF up-regulated the expression of alpha2beta1-integrin in a dose-dependent manner. EGF-induced cell migration was blocked by alpha2beta1-integrin antibody. Our results also showed that EGF treatment stimulated the level of tyrosine dephosphorylation of FAK, which is required for EGF-induced changes in motility, migration, and cell morphology. A tyrosine kinase inhibitor (ZD1839) blocked EGF-induced changes in cervical adenocarcinoma cells. The results suggest that EGF promotes cell motility and migration and increases the expression of alpha2beta1-integrin, possibly by decreasing FAK phosphorylation.
Collapse
Affiliation(s)
- Ikuhito Yamanaka
- Department of Obstetrics and Gynecology, Sapporo Medical University, School of Medicine, Sapporo, Japan.
| | | | | | | | | | | |
Collapse
|