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Areti A, Komirishetty P, Zochodne DW. Collaborative Roles for RAC1, ERM Proteins and PTEN During Adult Sensory Axon Regeneration. Mol Neurobiol 2024:10.1007/s12035-024-04273-7. [PMID: 38904854 DOI: 10.1007/s12035-024-04273-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 05/29/2024] [Indexed: 06/22/2024]
Abstract
The role of local of growth cone (GC) manipulation in adult regenerative systems is largely unexplored despite substantial translational importance. Here we investigated collaboration among Rac1 GTPase, its partnering ERM proteins and PTEN in adult sensory neurons and adult nerve regeneration. We confirmed expression of both Rac1 and ERM in adults and noted substantial impacts on neurite outgrowth in naïve and pre-injured adult sensory neurons. PTEN inhibition added to this outgrowth. Rac1 activation acted directly on adult GCs facilitating both attractive turning and advancement. In vivo regeneration indices including electrophysiological recovery, return of sensation, walking, repopulation of myelinated axons and reinnervation of the target epidermis indicated benefits of local Rac1 activation. These indices suggested maximal GC activation whereas local PTEN inhibition offered only limited added improvement. Our findings provide support for the concept of manipulating adult GCs, by emphasizing local Rac1 activation in directing therapy for nerve repair.
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Affiliation(s)
- Aparna Areti
- Division of Neurology, Department of Medicine and the Neuroscience and Mental Health Institute, University of Alberta, 7-132 Clinical Sciences Building 11350-83 Ave, T6G 2G3, Edmonton, AB, Canada
| | - Prashanth Komirishetty
- Division of Neurology, Department of Medicine and the Neuroscience and Mental Health Institute, University of Alberta, 7-132 Clinical Sciences Building 11350-83 Ave, T6G 2G3, Edmonton, AB, Canada
| | - Douglas W Zochodne
- Division of Neurology, Department of Medicine and the Neuroscience and Mental Health Institute, University of Alberta, 7-132 Clinical Sciences Building 11350-83 Ave, T6G 2G3, Edmonton, AB, Canada.
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Dufrancais O, Verdys P, Métais A, Juzans M, Sanchez T, Bergert M, Plozza M, Halper J, Panebianco CJ, Mascarau R, Gence R, Arnaud G, Neji MB, Maridonneau-Parini I, Cabec VL, Boerckel JD, Pavlos NJ, Diz-Muñoz A, Lagarrigue F, Blin-Wakkach C, Carréno S, Poincloux R, Burkhardt JK, Raynaud-Messina B, Vérollet C. Moesin activation controls bone resorption and tunneling nanotube-dependent osteoclast fusion. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.13.593799. [PMID: 38798563 PMCID: PMC11118517 DOI: 10.1101/2024.05.13.593799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Osteoclasts are multinucleated cells unique in their ability to resorb bone. Osteoclastogenesis involves several steps of actin-driven rearrangements that participate not only in the cell-cell fusion process, but also in the formation of the sealing zone, the adhesive structure determining the resorption area. Despite the importance of these actin cytoskeleton-based processes, their precise mechanisms of regulation are still poorly characterized. Here, we found that moesin, a member of the Ezrin/Radixin/Moesin (ERM) protein family, is activated during osteoclast maturation and plays an instrumental role for both osteoclast fusion and function. In mouse and human osteoclast precursors, moesin is negatively regulated to potentiate their ability to fuse and degrade bone. Accordingly, we demonstrated that moesin depletion decreases membrane-to-cortex attachment and enhances formation of tunneling nanotubes (TNTs), F-actin-containing intercellular bridges that we revealed to trigger osteoclast fusion. In addition, via a β3-integrin/RhoA/SLK pathway and independently of its role in fusion, moesin regulates the number and organization of sealing zones in mature osteoclast, and thus participates in the control of bone resorption. Supporting these findings, we found that moesin-deficient mice are osteopenic with a reduced density of trabecular bones and increased osteoclast abundance and activity. These findings provide a better understanding of the regulation of osteoclast biology, and open new opportunities to specifically target osteoclast activity in bone disease therapy.
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Zhou N, He M, Zhou G, Fan Q, Qi Y. Variant in EZR leads to defects in lens development. Ophthalmic Genet 2024:1-9. [PMID: 38563525 DOI: 10.1080/13816810.2024.2330391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 03/09/2024] [Indexed: 04/04/2024]
Abstract
BACKGROUND Congenital cataract is a common cause of blindness. Genetic factors always play important role. MATERIAL AND METHODS This study identified a novel missense variant (c.1412C>T (p.P471L)) in the EZR gene in a four-generation Chinese family with nuclear cataract by linkage analysis and whole-exome sequencing. A knockout study in zebrafish using transcription activator-like effector nucleases was carried out to gain insight into candidate gene function. RESULTS Conservative and functional prediction suggests that the P-to-L substitution may impair the function of the human ezrin protein. Histology showed developmental delays in the ezrin-mutated zebrafish, manifesting as multilayered lens epithelial cells. Immunohistochemistry revealed abnormal proliferation patterns in mutant fish. CONCLUSIONS The study suggests that ezrin may be involved in the enucleation and differentiation of lens epithelial cells.
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Affiliation(s)
- Nan Zhou
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Mingyan He
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Guangkai Zhou
- Department of Head and Neck Surgery, Harbin Medical University Cancer Hospital, The Third Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Qiuyang Fan
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Yanhua Qi
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
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Faure C, Djerbi-Bouillié R, Domingot A, Bouzinba-Segard H, Taouji S, Saidi Y, Bernard S, Carallis F, Rothe-Walther R, Lenormand JL, Chevet E, Bourdoulous S. Allosteric Inhibition of HER2 by Moesin-Mimicking Compounds Targets HER2-Positive Cancers and Brain Metastases. Cancer Res 2021; 81:5464-5476. [PMID: 34493594 DOI: 10.1158/0008-5472.can-21-0162] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 07/27/2021] [Accepted: 09/02/2021] [Indexed: 11/16/2022]
Abstract
Therapies targeting the tyrosine kinase receptor HER2 have significantly improved survival of patients with HER2+ cancer. However, both de novo and acquired resistance remain a challenge, particularly in the brain metastatic setting. Here we report that, unlike other HER tyrosine kinase receptors, HER2 possesses a binding motif in its cytosolic juxtamembrane region that allows interaction with members of the Ezrin/Radixin/Moesin (ERM) family. Under physiologic conditions, this interaction controls the localization of HER2 in ERM-enriched domains and stabilizes HER2 in a catalytically repressed state. In HER2+ breast cancers, low expression of Moesin correlated with increased HER2 expression. Restoring expression of ERM proteins in HER2+ breast cancer cells was sufficient to revert HER2 activation and inhibit HER2-dependent proliferation. A high-throughput assay recapitulating the HER2-ERM interaction allowed for screening of about 1,500 approved drugs. From this screen, we found Zuclopenthixol, an antipsychotic drug that behaved as a Moesin-mimicking compound, because it directly binds the juxtamembrane region of HER2 and specifically inhibits HER2 activation in HER2+ cancers, as well as activation of oncogenic mutated and truncated forms of HER2. Zuclopenthixol efficiently inhibited HER2+ breast tumor progression in vitro and in vivo and, more importantly, showed significant activity on HER2+ brain tumor progression. Collectively, these data reveal a novel class of allosteric HER2 inhibitors, increasing the number of approaches to consider for intervention on HER2+ breast cancers and brain metastases. SIGNIFICANCE: This study demonstrates the functional role of Moesin in maintaining HER2 in a catalytically repressed state and provides novel therapeutic approaches targeting HER2+ breast cancers and brain metastasis using Moesin-mimicking compounds.
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Affiliation(s)
- Camille Faure
- Université de Paris, Institut Cochin, Inserm, CNRS, Paris, France.
| | | | - Anaïs Domingot
- Université de Paris, Institut Cochin, Inserm, CNRS, Paris, France
| | | | - Saïd Taouji
- Inserm, Université de Bordeaux, Institut Bergonié, Bordeaux, France
| | - Yanis Saidi
- Université de Paris, Institut Cochin, Inserm, CNRS, Paris, France
| | - Sandra Bernard
- Université de Paris, Institut Cochin, Inserm, CNRS, Paris, France
| | | | - Romy Rothe-Walther
- TIMC-IMAG Laboratory, CNRS, Université Joseph Fourier, UFR de Médecine, La Tronche, France
| | - Jean-Luc Lenormand
- TIMC-IMAG Laboratory, CNRS, Université Joseph Fourier, UFR de Médecine, La Tronche, France
| | - Eric Chevet
- Inserm, Université de Bordeaux, Institut Bergonié, Bordeaux, France
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Markovic MA, Brubaker PL. The roles of glucagon-like peptide-2 and the intestinal epithelial insulin-like growth factor-1 receptor in regulating microvillus length. Sci Rep 2019; 9:13010. [PMID: 31506583 PMCID: PMC6737075 DOI: 10.1038/s41598-019-49510-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 08/27/2019] [Indexed: 12/25/2022] Open
Abstract
Microvilli are tiny projections on the apical end of enterocytes, aiding in the digestion and absorption of nutrients. One of their key features is uniform length, but how this is regulated is poorly understood. Glucagon-like peptide-2 (GLP-2) has been shown to increase microvillus length but, the requirement of its downstream mediator, the intestinal epithelial insulin-like growth factor-1 receptor (IE-IGF-1R), and the microvillus proteins acted upon by GLP-2, remain unknown. Using IE-IGF-1R knockout (KO) mice, treated with either long-acting human (h) (GLY2)GLP-2 or vehicle for 11d, it was found that the h(GLY2)GLP-2-induced increase in microvillus length required the IE-IGF-1R. Furthermore, IE-IGF-1R KO alone resulted in a significant decrease in microvillus length. Examination of the brush border membrane proteome as well as of whole jejunal mucosa demonstrated that villin was increased with h(GLY2)GLP-2 treatment in an IE-IGF-1R-dependent manner. Under both basal conditions and with h(GLY2)GLP-2 treatment of the IE-IGF-1R KO mice, changes in villin, IRTKS-1, harmonin, β-actin, and myosin-1a did not explain the decrease in microvillus length, in either the brush border or jejunal mucosa of KO animals. Collectively, these studies define a new role for the IE-IGF-1R within the microvillus, in both the signaling cascade induced by GLP-2, as well as endogenously.
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Affiliation(s)
- Melanie A Markovic
- Department of Physiology Rm 3366 Medical Sciences Building, University of Toronto, 1 King's College Circle, Toronto, ON, M5S 1A8, Canada
| | - Patricia L Brubaker
- Department of Physiology Rm 3366 Medical Sciences Building, University of Toronto, 1 King's College Circle, Toronto, ON, M5S 1A8, Canada. .,Department of Medicine Rm 3366 Medical Sciences Building, University of Toronto, 1 King's College Circle, Toronto, ON, M5S 1A8, Canada.
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Liu W, Chen G, Sun L, Zhang Y, Han J, Dai Y, He J, Shi S, Chen B. TUFT1 Promotes Triple Negative Breast Cancer Metastasis, Stemness, and Chemoresistance by Up-Regulating the Rac1/β-Catenin Pathway. Front Oncol 2019; 9:617. [PMID: 31338333 PMCID: PMC6629836 DOI: 10.3389/fonc.2019.00617] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 06/24/2019] [Indexed: 12/26/2022] Open
Abstract
Objectives: Triple negative breast cancer (TNBC) is a subtype of breast cancer with stronger invasion and metastasis, but its specific mechanism of action is still unclear. Tuft1 plays an important regulatory role in the survival of breast cancer cells; however, its role in regulating TNBC metastatic potential has not been well-characterized. Our aim was therefore to systematically study the mechanism of TUFT1 in the metastasis, stemness, and chemoresistance of TNBC and provide new predictors and targets for BC treatment. Methods: We used western blotting and IHC to measure TUFT1and Rac1-GTP expression levels in both human BC samples and cell lines. A combination of shRNA, migration/invasion assays, sphere formation assay, apoptosis assays, nude mouse xenograft tumor model, and GTP activity assays was used for further mechanistic studies. Results: We demonstrated that silencing TUFT1 in TNBC cells significantly inhibited cell metastasis and stemness in vitro. A nude mouse xenograft tumor model revealed that TUFT1 knockdown greatly decreased spontaneous lung metastasis of TNBC tumors. Mechanism studies showed that TUFT1 promoted tumor cell metastasis and stemness by up-regulating the Rac1/β-catenin pathway. Moreover, mechanistic studies indicated that the lack of TUFT1 expression in TNBC cells conferred more sensitive to chemotherapy and increased cell apoptosis via down-regulating the Rac1/β-catenin signaling pathway. Further, TUFT1 expression positively correlated with Rac1-GTP in TNBC samples, and co-expression of TUFT1 and Rac1-GTP predicted poor prognosis in TNBC patients who treated with chemotherapy. Conclusion: Our findings suggest that TUFT1/Rac1/β-catenin pathway may provide a potential target for more effective treatment of TNBC.
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Affiliation(s)
- Weiguang Liu
- Department of Breast Surgery, Affiliated Hospital of Hebei University of Engineering, Handan, China
| | - Guanglei Chen
- Department of Breast Surgery, Shengjing Hospital of China Medical University, Shenyang, China
| | - Lisha Sun
- Department of Breast Surgery, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yue Zhang
- Department of Physiology, Dalian Medical University, Dalian, China
| | - Jianjun Han
- Department of Breast Surgery, Affiliated Hospital of Hebei University of Engineering, Handan, China
| | - Yuna Dai
- Department of Breast Surgery, Affiliated Hospital of Hebei University of Engineering, Handan, China
| | - Jianchao He
- Department of Breast Surgery, Affiliated Hospital of Hebei University of Engineering, Handan, China
| | - Sufang Shi
- Department of Breast Surgery, Affiliated Hospital of Hebei University of Engineering, Handan, China
| | - Bo Chen
- Department of Breast Surgery, The First Hospital of China Medical University, Shenyang, China
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Vega IE, Umstead A, Wygant CM, Beck JS, Counts SE. Ezrin Expression is Increased During Disease Progression in a Tauopathy Mouse Model and Alzheimer's Disease. Curr Alzheimer Res 2018; 15:1086-1095. [PMID: 30101710 PMCID: PMC6522142 DOI: 10.2174/1567205015666180813152043] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 06/20/2018] [Accepted: 08/07/2018] [Indexed: 01/10/2023]
Abstract
BACKGROUND The lack of diagnostic tools and disease-modifying treatments against Alzheimer's disease (AD) and related disorders, collectively known as tauopathies, has led to a socioeconomic burden of epidemic proportion. Proteomics approaches can be used to identify novel proteome changes that could help us understand the pathogenesis of tau-related pathological hallmarks and/or cellular stress responses associated with tauopathy. These studies, however, need to be conducted taking into consideration brain region specificity and stage of neurodegeneration in order to provide insights about the pathological role of the identified proteins. METHODS We used a tauopathy mouse model (JNPL3) that expresses human tau bearing a P301L mutation and develops motor impairment, the severity of which correlates with the increased accumulation of pathological tau. Tissue was dissected from asymptomatic and severely motor impaired JNPL3 mice as well as non-transgenic littermate controls and subjected to two-dimensional gel electrophoresis. Differentially abundant protein spots were identified by tandem mass spectrometry. Postmortem mild cognitive impairment (MCI), AD and normal aging controls were used to validate the pathological significance of the identified protein. RESULTS Ezrin was identified as a protein that is upregulated in tau-mediated neurodegeneration. We demonstrate that Ezrin protein abundance increased in JNPL3 mice preceded motor impairment and was sustained in severely motor impaired mice. Ezrin expression was also increased in the temporal cortex of MCI and AD patients. CONCLUSION The results demonstrate that increased Ezrin protein abundance changes are associated with the early stages of neurodegeneration in tauopathy models and human disease. Understanding the role of Ezrin in tauopathies such as AD may provide new insights for targeting tau-mediated neurodegeneration.
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Affiliation(s)
- Irving E. Vega
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, Michigan, USA
- Department of Neurology, University of Michigan, Ann Arbor, Michigan, USA
- Michigan Alzheimer’s Disease Core Center, University of Michigan, Michigan State University and Wayne State University, Michigan, USA
| | - Andrew Umstead
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, Michigan, USA
| | - Cassandra M. Wygant
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, Michigan, USA
| | - John S. Beck
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, Michigan, USA
| | - Scott E. Counts
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, Michigan, USA
- Michigan Alzheimer’s Disease Core Center, University of Michigan, Michigan State University and Wayne State University, Michigan, USA
- Department of Family Medicine, College of Human Medicine, Michigan State University, Grand Rapids, Michigan, USA
- Hauenstein Neurosciences Center, Mercy Health Saint Mary’s Hospital, Grand Rapids, Michigan, USA
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8
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Gómez-Escudero J, Moreno V, Martín-Alonso M, Hernández-Riquer MV, Feinberg T, Colmenar Á, Calvo E, Camafeita E, Martínez F, Oudhoff MJ, Weiss SJ, Arroyo AG. E-cadherin cleavage by MT2-MMP regulates apical junctional signaling and epithelial homeostasis in the intestine. J Cell Sci 2017; 130:4013-4027. [PMID: 29061881 DOI: 10.1242/jcs.203687] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 10/13/2017] [Indexed: 12/11/2022] Open
Abstract
Cadherin-based intercellular adhesions are essential players in epithelial homeostasis, but their dynamic regulation during tissue morphogenesis and remodeling remain largely undefined. Here, we characterize an unexpected role for the membrane-anchored metalloproteinase MT2-MMP in regulating epithelial cell quiescence. Following co-immunoprecipitation and mass spectrometry, the MT2-MMP cytosolic tail was found to interact with the zonula occludens protein-1 (ZO-1) at the apical junctions of polarized epithelial cells. Functionally, MT2-MMP localizes in the apical domain of epithelial cells where it cleaves E-cadherin and promotes epithelial cell accumulation, a phenotype observed in 2D polarized cells as well as 3D cysts. MT2-MMP-mediated cleavage subsequently disrupts apical E-cadherin-mediated cell quiescence resulting in relaxed apical cortical tension favoring cell extrusion and re-sorting of Src kinase activity to junctional complexes, thereby promoting proliferation. Physiologically, MT2-MMP loss of function alters E-cadherin distribution, leading to impaired 3D organoid formation by mouse colonic epithelial cells ex vivo and reduction of cell proliferation within intestinal crypts in vivo Taken together, these studies identify an MT2-MMP-E-cadherin axis that functions as a novel regulator of epithelial cell homeostasis in vivo.
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Affiliation(s)
- Jesús Gómez-Escudero
- Matrix Metalloproteinases in Angiogenesis and Inflammation Group, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain
| | - Vanessa Moreno
- Matrix Metalloproteinases in Angiogenesis and Inflammation Group, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain
| | - Mara Martín-Alonso
- Centre of Molecular Inflammation Research (CEMIR), Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - M Victoria Hernández-Riquer
- Matrix Metalloproteinases in Angiogenesis and Inflammation Group, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain
| | - Tamar Feinberg
- Division of Molecular Medicine and Genetics, Department of Internal Medicine, Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ángel Colmenar
- Matrix Metalloproteinases in Angiogenesis and Inflammation Group, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain
| | - Enrique Calvo
- Proteomics Unit, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain
| | - Emilio Camafeita
- Proteomics Unit, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain
| | - Fernando Martínez
- Bioinformatics Unit, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain
| | - Menno J Oudhoff
- Centre of Molecular Inflammation Research (CEMIR), Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Stephen J Weiss
- Division of Molecular Medicine and Genetics, Department of Internal Medicine, Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Alicia G Arroyo
- Matrix Metalloproteinases in Angiogenesis and Inflammation Group, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain
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9
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Gamboa NT, Taussky P, Park MS, Couldwell WT, Mahan MA, Kalani MYS. Neurovascular patterning cues and implications for central and peripheral neurological disease. Surg Neurol Int 2017; 8:208. [PMID: 28966815 PMCID: PMC5609400 DOI: 10.4103/sni.sni_475_16] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 06/28/2017] [Indexed: 12/20/2022] Open
Abstract
The highly branched nervous and vascular systems run along parallel trajectories throughout the human body. This stereotyped pattern of branching shared by the nervous and vascular systems stems from a common reliance on specific cues critical to both neurogenesis and angiogenesis. Continually emerging evidence supports the notion of later-evolving vascular networks co-opting neural molecular mechanisms to ensure close proximity and adequate delivery of oxygen and nutrients to nervous tissue. As our understanding of these biologic pathways and their phenotypic manifestations continues to advance, identification of where pathways go awry will provide critical insight into central and peripheral nervous system pathology.
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Affiliation(s)
- Nicholas T Gamboa
- Department of Neurosurgery, Clinical Neurosciences Center, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Philipp Taussky
- Department of Neurosurgery, Clinical Neurosciences Center, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Min S Park
- Department of Neurosurgery, Clinical Neurosciences Center, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - William T Couldwell
- Department of Neurosurgery, Clinical Neurosciences Center, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Mark A Mahan
- Department of Neurosurgery, Clinical Neurosciences Center, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - M Yashar S Kalani
- Department of Neurosurgery, Clinical Neurosciences Center, University of Utah School of Medicine, Salt Lake City, Utah, USA
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He J, Ma G, Qian J, Zhu Y, Liang M, Yao N, Ding Q, Chen L, Liu X, Xia T, Wang S. Interaction Between Ezrin and Cortactin in Promoting Epithelial to Mesenchymal Transition in Breast Cancer Cells. Med Sci Monit 2017; 23:1583-1596. [PMID: 28364518 PMCID: PMC5386444 DOI: 10.12659/msm.904124] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 03/14/2017] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Epithelial to mesenchymal transition (EMT) contributes to metastases in various types of tumors, and is also the key step in the breast cancer metastatic cascade. In our previous study, a mouse model containing human-derived normal breast tissue was established and allowed EMT/MET process of human breast cancer cells to be mimicked in a humanized mammary microenvironment. MATERIAL AND METHODS Two-dimensional electrophoresis (2-DE) and mass spectrometry were used to detect different proteins between parental MDA-MB-231 and its variant sub-line obtained from tumors grown in transplanted normal human breast tissue (MDA-MB-231br). We knocked down the ezrin in 2 cell lines (MDA-MB-231 and SUM1315). The migration and invasion ability was assessed. EMT markers were examined by real-time reverse transcription PCR analysis and Western blot analysis. The relationship of ezrin with cortactin was tested by tissue microarray and co-immunoprecipitation. RESULTS Proteomic analysis revealed 81 differentially expressed proteins between parental MDA-MB-231 and MDA-MB-231br. Among these proteins, the expression of ezrin and cortactin and the phosphorylation of ezrin were significantly correlated, accompanied with a group of classic EMT makers. Knockdown of ezrin reversed the expression of EMT markers and downregulated cortactin and EMT transcription factors. Ezrin silencing inhibited tumor cell migration and invasion. Breast cancer tissue microarray and immunohistochemistry showed a significant positive association between ezrin and cortactin. CONCLUSIONS These findings indicate that ezrin is correlated with cortactin in facilitating EMT in breast cancer. The interaction between ezrin and cortactin is a novel mechanism contributing to the EMT process in cancer metastases.
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Affiliation(s)
- Jing He
- Department of Surgical Oncology, The Affiliated Hospital of Jiangnan University, Wuxi, Jiangsu, China (mainland)
| | - Ge Ma
- Breast Disease Center, 1st Affiliated Hospital with Nanjing Medical University, Nanjing, Jiangsu, China (mainland)
| | - Jiayi Qian
- Breast Disease Center, 1st Affiliated Hospital with Nanjing Medical University, Nanjing, Jiangsu, China (mainland)
| | - Yichao Zhu
- Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu, China (mainland)
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, Jiangsu, China (mainland)
| | - Mengdi Liang
- Breast Disease Center, 1st Affiliated Hospital with Nanjing Medical University, Nanjing, Jiangsu, China (mainland)
| | - Na Yao
- Breast Disease Center, 1st Affiliated Hospital with Nanjing Medical University, Nanjing, Jiangsu, China (mainland)
| | - Qiang Ding
- Breast Disease Center, 1st Affiliated Hospital with Nanjing Medical University, Nanjing, Jiangsu, China (mainland)
| | - Lin Chen
- Breast Disease Center, 1st Affiliated Hospital with Nanjing Medical University, Nanjing, Jiangsu, China (mainland)
| | - Xiaoan Liu
- Breast Disease Center, 1st Affiliated Hospital with Nanjing Medical University, Nanjing, Jiangsu, China (mainland)
| | - Tiansong Xia
- Breast Disease Center, 1st Affiliated Hospital with Nanjing Medical University, Nanjing, Jiangsu, China (mainland)
| | - Shui Wang
- Breast Disease Center, 1st Affiliated Hospital with Nanjing Medical University, Nanjing, Jiangsu, China (mainland)
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11
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Secretory cells in honeybee hypopharyngeal gland: polarized organization and age-dependent dynamics of plasma membrane. Cell Tissue Res 2016; 366:163-74. [PMID: 27210106 DOI: 10.1007/s00441-016-2423-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 04/25/2016] [Indexed: 01/14/2023]
Abstract
The honeybee hypopharyngeal gland consists in numerous units, each comprising a secretory cell and a canal cell. The secretory cell discharges its products into a convoluted tubular membrane system, the canaliculus, which is surrounded at regular intervals by rings of actin filaments. Using probes for various membrane components, we analyze the organization of the secretory cells relative to the apicobasal configuration of epithelial cells. The canaliculus was defined by labeling with an antibody against phosphorylated ezrin/radixin/moesin (pERM), a marker protein for the apical membrane domain of epithelial cells. Anti-phosphotyrosine visualizes the canalicular system, possibly by staining the microvillar tips. The open end of the canaliculus leads to a region in which the secretory cell is attached to the canal cell by adherens and septate junctions. The remaining plasma membrane stains for Na,K-ATPase and spectrin and represents the basolateral domain. We also used fluorophore-tagged phalloidin, anti-phosphotyrosine and anti-pERM as probes for the canaliculus in order to describe fine-structural changes in the organization of the canalicular system during the adult life cycle. These probes in conjunction with fluorescence microscopy allow the fast and detailed three-dimensional analysis of the canalicular membrane system and its structural changes in a developmental mode or in response to environmental factors.
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12
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Tu Z, Wang Q, Cui T, Wang J, Ran H, Bao H, Lu J, Wang B, Lydon JP, DeMayo F, Zhang S, Kong S, Wu X, Wang H. Uterine RAC1 via Pak1-ERM signaling directs normal luminal epithelial integrity conducive to on-time embryo implantation in mice. Cell Death Differ 2015; 23:169-81. [PMID: 26184908 DOI: 10.1038/cdd.2015.98] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Revised: 06/05/2015] [Accepted: 06/12/2015] [Indexed: 12/18/2022] Open
Abstract
Successful embryo implantation requires functional luminal epithelia to establish uterine receptivity and blastocyst-uterine adhesion. During the configuration of uterine receptivity from prereceptive phase, the luminal epithelium undergoes dynamic membrane reorganization and depolarization. This timely regulated epithelial membrane maturation and precisely maintained epithelial integrity are critical for embryo implantation in both humans and mice. However, it remained largely unexplored with respect to potential signaling cascades governing this functional epithelial transformation prior to implantation. Using multiple genetic and cellular approaches combined with uterine conditional Rac1 deletion mouse model, we demonstrated herein that Rac1, a small GTPase, is spatiotemporally expressed in the periimplantation uterus, and uterine depletion of Rac1 induces premature decrease of epithelial apical-basal polarity and defective junction remodeling, leading to disrupted uterine receptivity and implantation failure. Further investigations identified Pak1-ERM as a downstream signaling cascade upon Rac1 activation in the luminal epithelium necessary for uterine receptivity. In addition, we also demonstrated that Rac1 via P38 MAPK signaling ensures timely epithelial apoptotic death at postimplantation. Besides uncovering a potentially important molecule machinery governing uterine luminal integrity for embryo implantation, our finding has high clinical relevance, because Rac1 is essential for normal endometrial functions in women.
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Affiliation(s)
- Z Tu
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, PR China.,University of the Chinese Academy of Sciences, Beijing 100039, PR China
| | - Q Wang
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, PR China
| | - T Cui
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, PR China.,University of the Chinese Academy of Sciences, Beijing 100039, PR China
| | - J Wang
- Department of Pharmacology, Zhejiang University, Hangzhou 310058, PR China
| | - H Ran
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, PR China.,State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100039, PR China
| | - H Bao
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, PR China.,State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100039, PR China
| | - J Lu
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, PR China
| | - B Wang
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, PR China
| | - J P Lydon
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - F DeMayo
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - S Zhang
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, PR China
| | - S Kong
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, PR China
| | - X Wu
- Department of Pharmacology, Zhejiang University, Hangzhou 310058, PR China
| | - H Wang
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, PR China
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13
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Lagendijk AK, Yap AS, Hogan BM. Endothelial cell-cell adhesion during zebrafish vascular development. Cell Adh Migr 2015; 8:136-45. [PMID: 24621476 DOI: 10.4161/cam.28229] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The vertebrate vasculature is an essential organ network with major roles in health and disease. The establishment of balanced cell-cell adhesion in the endothelium is crucial for the functionality of the vascular system. Furthermore, the correct patterning and integration of vascular endothelial cell-cell adhesion drives the morphogenesis of new vessels, and is thought to couple physical forces with signaling outcomes during development. Here, we review insights into this process that have come from studies in zebrafish. First, we describe mutants in which endothelial adhesion is perturbed, second we describe recent progress using in vivo cell biological approaches that allow the visualization of endothelial cell-cell junctions. These studies underline the profound potential of this model system to dissect in great detail the function of both known and novel regulators of endothelial cell-cell adhesion.
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Affiliation(s)
- Anne K Lagendijk
- Institute for Molecular Bioscience; The University of Queensland;Brisbane, QLD, Australia
| | - Alpha S Yap
- Institute for Molecular Bioscience; The University of Queensland;Brisbane, QLD, Australia
| | - Benjamin M Hogan
- Institute for Molecular Bioscience; The University of Queensland;Brisbane, QLD, Australia
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14
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Qi W, Tian J, Su S, Huang L, Li H, Liao M. Identification of potential virulence determinants associated H9N2 avian influenza virus PB2 E627K mutation by comparative proteomics. Proteomics 2015; 15:1512-24. [PMID: 25641917 DOI: 10.1002/pmic.201400309] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 12/03/2014] [Accepted: 01/13/2015] [Indexed: 12/14/2022]
Abstract
Some highly pathogenic H5N1, H7N9, and H10N8 isolated from China carried six internal genes from H9N2 avian influenza viruses (AIV) and the key amino acids at 627 in PB2 of these viruses had mutated to K. To investigate the mechanism of increased pathogenicity for H9N2 AIV PB2 627K, we analyzed the difference in mouse lung proteins expression response to PB2 K627E. By iTRAQ method, we found that the mutated K627E contributed to a set of differentially expressed lung proteins, including five upregulated proteins and nine downregulated proteins at 12 h postinfection; ten upregulated proteins and 25 downregulated proteins at 72 h postinfection. These proteins were chiefly involved within the cytoskeleton and motor proteins, antiviral proteins, regulation of glucocorticoids signal-associated proteins, pro- and anti-inflammatory proteins. Alteration of moesin, FKBP4, Hsp70, ezrin, and pulmonary surfactant protein A (sp-A) may play important roles in increasing virulence and decreasing lungs antiviral response. Further, three upregulated proteins (moesin, ezrin, and sp-A) caused by PB2 K627E were also confirmed in A549 cells. Moreover, overexpression of sp-A in A549 inhibited virus replication and downregulation promoted virus replication. In this study, sp-A as a potential virulence determinant associated H9N2 AIV PB2 E627K mutation was identified using comparative proteomics.
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Affiliation(s)
- Wenbao Qi
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, P. R. China
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15
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Chen YX, Zhang W, Wang WM, Yu XL, Wang YM, Zhang MJ, Chen N. Role of moesin in renal fibrosis. PLoS One 2014; 9:e112936. [PMID: 25406076 PMCID: PMC4236084 DOI: 10.1371/journal.pone.0112936] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Accepted: 10/17/2014] [Indexed: 01/13/2023] Open
Abstract
Background Renal fibrosis is the final common pathway of chronic kidney disease (CKD). Moesin is a member of Ezrin/Radixin/Moesin (ERM) protein family but its role in renal fibrosis is not clear. Method Human proximal tubular cells (HK-2) were stimulated with or without TGF-β1. Moesin and downstream target genes were examined by real-time PCR and western blot. Phosphorylation of moesin and related signaling pathway was investigated as well. Rat model of unilateral ureteral obstruction (UUO) was established and renal moesin was examined by immunohistochemistry. Moesin in HK-2 cells were knocked down by siRNA and change of downstream genes in transfected HK-2 cells was studied. All animal experiments were reviewed and approved by the Ethics Committee for animal care of Ruijin Hospital. Result HK-2 cells stimulated with TGF-β1 showed up-regulated level of α-SMA and down-regulated level of E-Cadherin as well as elevated mRNA and protein level of moesin. In rat model of UUO, renal moesin expression increased in accordance with severity of tubulointerestital fibrosis in the kidneys with ureteral ligation while the contralateral kidneys were normal. Further study showed that TGF-β1 could induce phosphorylation of moesin which depended on Erk signaling pathway and Erk inhibitor PD98059 could block moesin phosphorylation. Effects of TGF-β1 on moesin phosphorylation was prior to its activation to total moesin. RNA silencing studies showed that knocking down of moesin could attenuate decrease of E-Cadherin induced by TGF-β1. Conclusion We find that moesin might be involved in renal fibrosis and its effects could be related to interacting with E-Cadherin.
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Affiliation(s)
- Yong-Xi Chen
- Department of nephrology, Ruijin Hospital, Shanghai Jiaotong University, school of medicine, Shanghai, PR China
| | - Wen Zhang
- Department of nephrology, Ruijin Hospital, Shanghai Jiaotong University, school of medicine, Shanghai, PR China
| | - Wei-Ming Wang
- Department of nephrology, Ruijin Hospital, Shanghai Jiaotong University, school of medicine, Shanghai, PR China
| | - Xia-Lian Yu
- Department of nephrology, Ruijin Hospital, Shanghai Jiaotong University, school of medicine, Shanghai, PR China
| | - Yi-Mei Wang
- Department of nephrology, Ruijin Hospital, Shanghai Jiaotong University, school of medicine, Shanghai, PR China
| | - Min-Jun Zhang
- Animal Experiment and Research Center, Ruijin Hospital, Shanghai Jiaotong University, school of medicine, Shanghai, PR China
| | - Nan Chen
- Department of nephrology, Ruijin Hospital, Shanghai Jiaotong University, school of medicine, Shanghai, PR China
- * E-mail:
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16
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Mulinari S, Häcker U. Rho-guanine nucleotide exchange factors during development: Force is nothing without control. Small GTPases 2014; 1:28-43. [PMID: 21686118 DOI: 10.4161/sgtp.1.1.12672] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2010] [Revised: 05/31/2010] [Accepted: 06/14/2010] [Indexed: 01/04/2023] Open
Abstract
The development of multicellular organisms is associated with extensive rearrangements of tissues and cell sheets. The driving force for these rearrangements is generated mostly by the actin cytoskeleton. In order to permit the reproducible development of a specific body plan, dynamic reorganization of the actin cytoskeleton must be precisely coordinated in space and time. GTP-exchange factors that activate small GTPases of the Rho family play an important role in this process. Here we review the role of this class of cytoskeletal regulators during important developmental processes such as epithelial morphogenesis, cytokinesis, cell migration, cell polarity, neuronal growth cone extension and phagocytosis in different model systems.
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Affiliation(s)
- Shai Mulinari
- Department of Experimental Medical Science; Lund Strategic Research Center for Stem Cell Biology and Cell Therapy; Lund University; Lund, Sweden
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17
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Ukken FP, Aprill I, JayaNandanan N, Leptin M. Slik and the receptor tyrosine kinase Breathless mediate localized activation of Moesin in terminal tracheal cells. PLoS One 2014; 9:e103323. [PMID: 25061859 PMCID: PMC4111555 DOI: 10.1371/journal.pone.0103323] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 07/01/2014] [Indexed: 11/21/2022] Open
Abstract
A key element in the regulation of subcellular branching and tube morphogenesis of the Drosophila tracheal system is the organization of the actin cytoskeleton by the ERM protein Moesin. Activation of Moesin within specific subdomains of cells, critical for its interaction with actin, is a tightly controlled process and involves regulatory inputs from membrane proteins, kinases and phosphatases. The kinases that activate Moesin in tracheal cells are not known. Here we show that the Sterile-20 like kinase Slik, enriched at the luminal membrane, is necessary for the activation of Moesin at the luminal membrane and regulates branching and subcellular tube morphogenesis of terminal cells. Our results reveal the FGF-receptor Breathless as an additional necessary cue for the activation of Moesin in terminal cells. Breathless-mediated activation of Moesin is independent of the canonical MAP kinase pathway.
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Affiliation(s)
| | - Imola Aprill
- Directors' Research, European Molecular Biology Laboratory, Heidelberg, Germany
| | - N. JayaNandanan
- Directors' Research, European Molecular Biology Laboratory, Heidelberg, Germany
- * E-mail: (NJ); (ML)
| | - Maria Leptin
- Institute of Genetics, University of Cologne, Cologne, Germany
- Directors' Research, European Molecular Biology Laboratory, Heidelberg, Germany
- * E-mail: (NJ); (ML)
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18
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Chen M, Liu T, Xu L, Gao X, Liu X, Wang C, He Q, Zhang G, Liu L. Direct interaction of 14-3-3ζ with ezrin promotes cell migration by regulating the formation of membrane ruffle. J Mol Biol 2014; 426:3118-3133. [PMID: 25020230 DOI: 10.1016/j.jmb.2014.06.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 06/26/2014] [Accepted: 06/27/2014] [Indexed: 12/30/2022]
Abstract
14-3-3 proteins have been shown to regulate the actin cytoskeleton remodeling, cell adhesion and migration. In this study, we identified ezrin, a cross-linker between plasma membrane and actin cytoskeleton, as a novel 14-3-3ζ interacting partner. The direct interaction between 14-3-3ζ and ezrin was validated in the cells and by in vitro assays. We showed that the 14-3-3ζ binding region in ezrin was located within the N-terminal and central α-helical domains and that the αG-to-αI helices of 14-3-3ζ are responsible for the binding to ezrin. Functional analyses revealed that the regulation of cell migration and membrane ruffling by 14-3-3ζ is ezrin dependent, for which the integrity of ezrin protein was required. Conversely, the knockdown of 14-3-3ζ abrogates also the stimulatory effect of ezrin on cell migration and membrane ruffling. Moreover, we found that the phosphorylation of Thr567 in ezrin facilitates the 14-3-3ζ-ezrin interaction and the formation of membrane ruffles. Taken together, these results suggest strongly that the functions of these two proteins in cell migration are linked and might be mediated by their direct physical interaction, which is important for the formation of membrane ruffles.
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Affiliation(s)
- Miaojuan Chen
- Key Laboratory of Functional Protein Research of Guangdong Higher Education, Institute of Life and Health Engineering, Jinan University, Guangzhou 510632, China
| | - Tengfei Liu
- Key Laboratory of Functional Protein Research of Guangdong Higher Education, Institute of Life and Health Engineering, Jinan University, Guangzhou 510632, China
| | - Lina Xu
- Key Laboratory of Functional Protein Research of Guangdong Higher Education, Institute of Life and Health Engineering, Jinan University, Guangzhou 510632, China
| | - Xuejuan Gao
- Key Laboratory of Functional Protein Research of Guangdong Higher Education, Institute of Life and Health Engineering, Jinan University, Guangzhou 510632, China
| | - Xiaohui Liu
- Key Laboratory of Functional Protein Research of Guangdong Higher Education, Institute of Life and Health Engineering, Jinan University, Guangzhou 510632, China
| | - Cuihua Wang
- Key Laboratory of Functional Protein Research of Guangdong Higher Education, Institute of Life and Health Engineering, Jinan University, Guangzhou 510632, China
| | - Qingyu He
- Key Laboratory of Functional Protein Research of Guangdong Higher Education, Institute of Life and Health Engineering, Jinan University, Guangzhou 510632, China
| | - Gong Zhang
- Key Laboratory of Functional Protein Research of Guangdong Higher Education, Institute of Life and Health Engineering, Jinan University, Guangzhou 510632, China
| | - Langxia Liu
- Key Laboratory of Functional Protein Research of Guangdong Higher Education, Institute of Life and Health Engineering, Jinan University, Guangzhou 510632, China..
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Escobar-Restrepo JM, Hajnal A. An intimate look at LET-23 EGFR trafficking in the vulval cells of live C. elegans larvae. WORM 2014; 3:e965605. [PMID: 26430550 PMCID: PMC4588154 DOI: 10.4161/21624046.2014.965605] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 09/09/2014] [Indexed: 01/07/2023]
Abstract
Precise cell fate specification is essential for organ formation. A simple view is that one or several signal sending cells emit a ligand to a group of signal receiving cells that express the corresponding receptor, which transduces the signal through intracellular enzyme pathways. All these events must be spatio-temporally regulated to achieve the proper strength, duration and output of the signaling pathways. In particular, the production and secretion of the ligand has to be coordinated with the expression and accessibility of the receptor in the signal receiving cells. Furthermore, removal of the ligand or receptor is key to achieve proper signal termination and prevent excess cell differentiation and proliferation. Improper regulation of any of these events may cause developmental defects and human disease. C. elegans is an excellent model to systematically identify genes that control the localization and activity of the Epidermal Growth Factor Receptor (EGFR) homolog LET-23. To identify regulators of LET-23 trafficking, Haag et al. observed LET-23 localization in the vulva precursor cells (VPCs) of RNAi treated larvae by live fluorescent microscopy. In this comment, we provide an overview of the newly identified regulators of LET-23 trafficking and discuss the role of the Ezrin/Radixin/Moesin homolog ERM-1 as a temporal regulator of EGFR signaling.
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Affiliation(s)
- Juan M Escobar-Restrepo
- University of Zurich; Institute of Molecular Life Sciences; Winterthurerstrasse; Zurich, Switzerland
| | - Alex Hajnal
- University of Zurich; Institute of Molecular Life Sciences; Winterthurerstrasse; Zurich, Switzerland
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20
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An in vivo EGF receptor localization screen in C. elegans Identifies the Ezrin homolog ERM-1 as a temporal regulator of signaling. PLoS Genet 2014; 10:e1004341. [PMID: 24785082 PMCID: PMC4006739 DOI: 10.1371/journal.pgen.1004341] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 03/16/2014] [Indexed: 11/19/2022] Open
Abstract
The subcellular localization of the epidermal growth factor receptor (EGFR) in polarized epithelial cells profoundly affects the activity of the intracellular signaling pathways activated after EGF ligand binding. Therefore, changes in EGFR localization and signaling are implicated in various human diseases, including different types of cancer. We have performed the first in vivo EGFR localization screen in an animal model by observing the expression of the EGFR ortholog LET-23 in the vulval epithelium of live C. elegans larvae. After systematically testing all genes known to produce an aberrant vulval phenotype, we have identified 81 genes regulating various aspects of EGFR localization and expression. In particular, we have found that ERM-1, the sole C. elegans Ezrin/Radixin/Moesin homolog, regulates EGFR localization and signaling in the vulval cells. ERM-1 interacts with the EGFR at the basolateral plasma membrane in a complex distinct from the previously identified LIN-2/LIN-7/LIN-10 receptor localization complex. We propose that ERM-1 binds to and sequesters basolateral LET-23 EGFR in an actin-rich inactive membrane compartment to restrict receptor mobility and signaling. In this manner, ERM-1 prevents the immediate activation of the entire pool of LET-23 EGFR and permits the generation of a long-lasting inductive signal. The regulation of receptor localization thus serves to fine-tune the temporal activation of intracellular signaling pathways. Abnormal signaling by the epidermal growth factor receptor (EGFR) contributes to the development of various human diseases, including different cancer types. One important mechanism that controls intracellular signal transduction is by regulation of the subcellular receptor localization in the signal-receiving cell. We are investigating the regulation of the EGFR homolog LET-23 in the Nematode C. elegans by observing the localization of the EGFR in the epithelial cells of live animals. This approach has allowed us to study the dynamics of receptor trafficking in cells embedded in their natural environment and receiving physiological concentrations of various extracellular signals. In a systematic RNA interference screen, we have identified 81 genes controlling EGFR localization and signaling in different subcellular compartments. One new regulator of EGFR signaling identified in this screen encodes the Ezrin Homolog ERM-1. We show genetic and biochemical evidence indicating that ERM-1 is part of a buffering mechanism to maintain a pool of immobile EGFR in the basolateral membrane compartment of the epithelial cells. This mechanism permits the generation of a long-lasting EGFR signal during multiple rounds of cell divisions. The control of receptor localization is thus necessary for the precise temporal regulation of signal transduction during animal development.
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Arumugam P, Partelli S, Coleman SJ, Cataldo I, Beghelli S, Bassi C, Wijesuriya N, Aleong JAC, Froeling FEM, Scarpa A, Kocher HM. Ezrin expression is an independent prognostic factor in gastro-intestinal cancers. J Gastrointest Surg 2013; 17:2082-91. [PMID: 24155054 DOI: 10.1007/s11605-013-2384-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 10/04/2013] [Indexed: 01/31/2023]
Abstract
BACKGROUND Ezrin, a member of the ezrin-radixin-moesin (ERM) family of plasma membrane-cytoskeleton linker proteins, has been associated with metastatic behavior. METHODOLOGY Microarrayed pathological tissues of surgically resected colorectal cancer liver metastasis (CRLM) and whole tissue sections of cancer of the ampulla of Vater (CAV) were analyzed to determine ezrin expression levels and correlation with survival. The requirement of ezrin in invasive capability was assessed using in vitro assays. RESULTS Surgically resected CAV showing a low ezrin score have a better 5-year disease-specific survival than those showing a high ezrin score (P < 0.0001). Similarly, high ezrin expression at the invasive front of CRLM resulted in poor disease-free survival (P = 0.05). Multivariate analysis demonstrated high ezrin expression to be an independent adverse prognostic factor for CAV (hazard ratio (HR) 15.22 (95 % confidence interval (CI) 1.98-117.03), P < 0.01) and CRLM (HR 6.42 (95 % CI 1.01-52.43), P = 0.05), among other clinically relevant variables such as lymph node metastasis (for CAV) and the presence of extrahepatic disease, large hepatic metastases (>5 cm), and close surgical resection margins (<5 mm) (all for CRLM). In vitro experiments indicated that ezrin expression was vital for cellular processes such as adhesive and invasive activity. SIGNIFICANCE High ezrin expression indicates an adverse prognosis in primary CAV and CRLM.
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Affiliation(s)
- Prabhu Arumugam
- Centre for Tumour Biology, John Vane Science Centre, Barts Cancer Institute-a CR-UK Centre of Excellence, Queen Mary University of London, Charterhouse Square, London, EC1M 6BQ, UK
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22
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Solinet S, Mahmud K, Stewman SF, Ben El Kadhi K, Decelle B, Talje L, Ma A, Kwok BH, Carreno S. The actin-binding ERM protein Moesin binds to and stabilizes microtubules at the cell cortex. J Cell Biol 2013; 202:251-60. [PMID: 23857773 PMCID: PMC3718980 DOI: 10.1083/jcb.201304052] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 06/07/2013] [Indexed: 01/15/2023] Open
Abstract
Ezrin, Radixin, and Moesin (ERM) proteins play important roles in many cellular processes including cell division. Recent studies have highlighted the implications of their metastatic potential in cancers. ERM's role in these processes is largely attributed to their ability to link actin filaments to the plasma membrane. In this paper, we show that the ERM protein Moesin directly binds to microtubules in vitro and stabilizes microtubules at the cell cortex in vivo. We identified two evolutionarily conserved residues in the FERM (4.1 protein and ERM) domains of ERMs that mediated the association with microtubules. This ERM-microtubule interaction was required for regulating spindle organization in metaphase and cell shape transformation after anaphase onset but was dispensable for bridging actin filaments to the metaphase cortex. These findings provide a molecular framework for understanding the complex functional interplay between the microtubule and actin cytoskeletons mediated by ERM proteins in mitosis and have broad implications in both physiological and pathological processes that require ERMs.
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Affiliation(s)
- Sara Solinet
- Cellular Mechanisms of Morphogenesis during Mitosis and Cell Motility and Chemical Biology of Cell Division, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Kazi Mahmud
- Cellular Mechanisms of Morphogenesis during Mitosis and Cell Motility and Chemical Biology of Cell Division, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Shannon F. Stewman
- Department of Bioengineering, The University of Illinois at Chicago, Chicago, IL 60607
| | - Khaled Ben El Kadhi
- Cellular Mechanisms of Morphogenesis during Mitosis and Cell Motility and Chemical Biology of Cell Division, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Barbara Decelle
- Cellular Mechanisms of Morphogenesis during Mitosis and Cell Motility and Chemical Biology of Cell Division, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Lama Talje
- Cellular Mechanisms of Morphogenesis during Mitosis and Cell Motility and Chemical Biology of Cell Division, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Ao Ma
- Department of Bioengineering, The University of Illinois at Chicago, Chicago, IL 60607
| | - Benjamin H. Kwok
- Cellular Mechanisms of Morphogenesis during Mitosis and Cell Motility and Chemical Biology of Cell Division, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Québec H3C 3J7, Canada
- Département de médecine and Département de Pathologie et de Biologie Cellulaire, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Sébastien Carreno
- Cellular Mechanisms of Morphogenesis during Mitosis and Cell Motility and Chemical Biology of Cell Division, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Québec H3C 3J7, Canada
- Département de médecine and Département de Pathologie et de Biologie Cellulaire, Université de Montréal, Montréal, Québec H3C 3J7, Canada
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23
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Lindner C, Urbánek P, Pavelka B, Hartmann M, Herrlich P. A link between two tumorigenic proteins, CD44 and p21WAF1: CD44 increases phorbol ester-induced expression of p21WAF1 by stabilizing its mRNA and extending protein half-life. FEBS Lett 2013; 587:2698-704. [PMID: 23856463 DOI: 10.1016/j.febslet.2013.07.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Accepted: 07/01/2013] [Indexed: 01/23/2023]
Abstract
The cell surface glycoprotein CD44 enhances phorbol-12-myristate 13-acetate (TPA)-induced expression of p21WAF1 by stabilizing its mRNA and enhancing the protein's half-life in several cell lines. Only the plasma membrane-anchored cytoplasmic tail of CD44 and its interacting ezrin, radixin, moesin (ERM) proteins are required for this effect. A mitogen activated kinase (MEK) inhibitor abolishes the action of CD44 on p21. Down-regulation of p21 dramatically decreased anchorage-independence of a cancer cell line, whereas CD44 expression in this background could partially rescue the phenotype.
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Affiliation(s)
- Christina Lindner
- Leibniz Institute for Age Research - Fritz Lipmann Institute, Beutenbergstr. 11, 07745 Jena, Germany
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Di Sole F, Vadnagara K, Moe OW, Babich V. Calcineurin homologous protein: a multifunctional Ca2+-binding protein family. Am J Physiol Renal Physiol 2012; 303:F165-79. [PMID: 22189947 PMCID: PMC3404583 DOI: 10.1152/ajprenal.00628.2011] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Accepted: 05/17/2012] [Indexed: 12/13/2022] Open
Abstract
The calcineurin homologous protein (CHP) belongs to an evolutionarily conserved Ca(2+)-binding protein subfamily. The CHP subfamily is composed of CHP1, CHP2, and CHP3, which in vertebrates share significant homology at the protein level with each other and between other Ca(2+)-binding proteins. The CHP structure consists of two globular domains containing from one to four EF-hand structural motifs (calcium-binding regions composed of two helixes, E and F, joined by a loop), the myristoylation, and nuclear export signals. These structural features are essential for the function of the three members of the CHP subfamily. Indeed, CHP1-CHP3 have multiple and diverse essential functions, ranging from the regulation of the plasma membrane Na(+)/H(+) exchanger protein function, to carrier vesicle trafficking and gene transcription. The diverse functions attributed to the CHP subfamily rendered an understanding of its action highly complex and often controversial. This review provides a comprehensive and organized examination of the properties and physiological roles of the CHP subfamily with a view to revealing a link between CHP diverse functions.
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Affiliation(s)
- Francesca Di Sole
- Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Blvd., Dallas, TX 75390-8885, USA.
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Ben-Aissa K, Patino-Lopez G, Belkina NV, Maniti O, Rosales T, Hao JJ, Kruhlak MJ, Knutson JR, Picart C, Shaw S. Activation of moesin, a protein that links actin cytoskeleton to the plasma membrane, occurs by phosphatidylinositol 4,5-bisphosphate (PIP2) binding sequentially to two sites and releasing an autoinhibitory linker. J Biol Chem 2012; 287:16311-23. [PMID: 22433855 DOI: 10.1074/jbc.m111.304881] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Many cellular processes depend on ERM (ezrin, moesin, and radixin) proteins mediating regulated linkage between plasma membrane and actin cytoskeleton. Although conformational activation of the ERM protein is mediated by the membrane PIP2, the known properties of the two described PIP2-binding sites do not explain activation. To elucidate the structural basis of possible mechanisms, we generated informative moesin mutations and tested three attributes: membrane localization of the expressed moesin, moesin binding to PIP2, and PIP2-induced release of moesin autoinhibition. The results demonstrate for the first time that the POCKET containing inositol 1,4,5-trisphosphate on crystal structure (the "POCKET" Lys-63, Lys-278 residues) mediates all three functions. Furthermore the second described PIP2-binding site (the "PATCH," Lys-253/Lys-254, Lys-262/Lys-263) is also essential for all three functions. In native autoinhibited ERM proteins, the POCKET is a cavity masked by an acidic linker, which we designate the "FLAP." Analysis of three mutant moesin constructs predicted to influence FLAP function demonstrated that the FLAP is a functional autoinhibitory region. Moreover, analysis of the cooperativity and stoichiometry demonstrate that the PATCH and POCKET do not bind PIP2 simultaneously. Based on our data and supporting published data, we propose a model of progressive activation of autoinhibited moesin by a single PIP2 molecule in the membrane. Initial transient binding of PIP2 to the PATCH initiates release of the FLAP, which enables transition of the same PIP2 molecule into the newly exposed POCKET where it binds stably and completes the conformational activation.
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Affiliation(s)
- Khadija Ben-Aissa
- Experimental Immunology Branch, NCI, National Institutes of Health, Bethesda, Maryland 20892, USA
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Valderrama F, Thevapala S, Ridley AJ. Radixin regulates cell migration and cell-cell adhesion through Rac1. J Cell Sci 2012; 125:3310-9. [DOI: 10.1242/jcs.094383] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The ERM proteins ezrin, radixin and moesin are adaptor proteins that link plasma membrane receptors to the actin cytoskeleton. Ezrin and moesin have been implicated in cell polarization and cell migration, but little is known about the involvement of radixin in these processes. Here we show that radixin is required for migration of PC3 prostate cancer cells, and that radixin, but not ezrin or moesin, depletion by RNAi increases cell spread area and cell-cell adhesion mediated by adherens junctions. Radixin depletion also alters actin organization and distribution of active phosphorylated ezrin and moesin. Similar effects were observed in MDA-MB-231 breast cancer cells. The phenotype of radixin-depleted cells is similar to that induced by constitutively active Rac1, and Rac1 is required for the radixin knockdown phenotype. Radixin depletion also increases the activity of Rac1 but not Cdc42 or RhoA. Analysis of Rac guanine nucleotide exchange factors (GEFs) suggests that radixin affects the activity of Vav GEFs. Indeed, Vav GEF depletion reverts the phenotype of radixin knockdown and reduces the effect of radixin knockdown on Rac1 activity. Our results indicate that radixin plays an important role in promoting cell migration by regulating Rac1-mediated epithelial polarity and formation of adherens junctions through Vav GEFs.
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Fong B, Barkhoudarian G, Pezeshkian P, Parsa AT, Gopen Q, Yang I. The molecular biology and novel treatments of vestibular schwannomas. J Neurosurg 2011; 115:906-14. [PMID: 21800959 DOI: 10.3171/2011.6.jns11131] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Vestibular schwannomas are histopathologically benign tumors arising from the Schwann cell sheath surrounding the vestibular branch of cranial nerve VIII and are related to the NF2 gene and its product merlin. Merlin acts as a tumor suppressor and as a mediator of contact inhibition. Thus, deficiencies in both NF2 genes lead to vestibular schwannoma development. Recently, there have been major advances in our knowledge of the molecular biology of vestibular schwannomas as well as the development of novel therapies for its treatment. In this article the authors comprehensively review the recent advances in the molecular biology and characterization of vestibular schwannomas as well as the development of modern treatments for vestibular schwannoma. For instance, merlin is involved with a number of receptors including the CD44 receptor, EGFR, and signaling pathways, such as the Ras/raf pathway and the canonical Wnt pathway. Recently, merlin was also shown to interact in the nucleus with E3 ubiquitin ligase CRL4(DCAF1). A greater understanding of the molecular mechanisms behind vestibular schwannoma tumorigenesis has begun to yield novel therapies. Some authors have shown that Avastin induces regression of progressive schwannomas by over 40% and improves hearing. An inhibitor of VEGF synthesis, PTC299, is currently in Phase II trials as a potential agent to treat vestibular schwannoma. Furthermore, in vitro studies have shown that trastuzumab (an ERBB2 inhibitor) reduces vestibular schwannoma cell proliferation. With further research it may be possible to significantly reduce morbidity and mortality rates by decreasing tumor burden, tumor volume, hearing loss, and cranial nerve deficits seen in vestibular schwannomas.
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Affiliation(s)
- Brendan Fong
- Department of Neurological Surgery, University of California, Los Angeles, CA 90095-1761, USA
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Chan D, Citro A, Cordy JM, Shen GC, Wolozin B. Rac1 protein rescues neurite retraction caused by G2019S leucine-rich repeat kinase 2 (LRRK2). J Biol Chem 2011; 286:16140-9. [PMID: 21454543 DOI: 10.1074/jbc.m111.234005] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mutations in leucine-rich repeat kinase 2 (LRRK2) are currently the most common genetic cause of familial late-onset Parkinson disease, which is clinically indistinguishable from idiopathic disease. The most common pathological mutation in LRRK2, G2019S LRRK2, is known to cause neurite retraction. However, molecular mechanisms underlying regulation of neurite length by LRRK2 are unknown. Here, we demonstrate a novel interaction between LRRK2 and the Rho GTPase, Rac1, which plays a critical role in actin cytoskeleton remodeling necessary for the maintenance of neurite morphology. LRRK2 binds strongly to endogenous or expressed Rac1, while showing weak binding to Cdc42 and no binding to RhoA. Co-expression with LRRK2 increases Rac1 activity, as shown by increased binding to the p21-activated kinase, which modulates actin cytoskeletal dynamics. LRRK2 constructs carrying mutations that inactivate the kinase or GTPase activities do not activate Rac1. Interestingly, LRRK2 does not increase levels of membrane-bound Rac1 but dramatically changes the cellular localization of Rac1, causing polarization, which is augmented further when LRRK2 is co-expressed with constitutively active Rac1. Four different disease-related mutations in LRRK2 altered binding to Rac1, with the G2019S and R1441C LRRK2 mutations attenuating Rac1 binding and the Y1699C and I2020T LRRK2 mutations increasing binding. Co-expressing Rac1 in SH-SY5Y cells rescues the G2019S mutant phenotype of neurite retraction. We hypothesize that pathological mutations in LRRK2 attenuates activation of Rac1, causing disassembly of actin filaments, leading to neurite retraction. The interactions between LRRK2 and Rho GTPases provide a novel pathway through which LRRK2 might modulate cellular dynamics and contribute to the pathophysiology of Parkinson disease.
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Affiliation(s)
- Diane Chan
- Department of Pharmacology, Boston University School of Medicine, Boston, Massachusetts 02118-2526, USA
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Marion S, Hoffmann E, Holzer D, Le Clainche C, Martin M, Sachse M, Ganeva I, Mangeat P, Griffiths G. Ezrin promotes actin assembly at the phagosome membrane and regulates phago-lysosomal fusion. Traffic 2011; 12:421-37. [PMID: 21210911 DOI: 10.1111/j.1600-0854.2011.01158.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Phagosome maturation is defined as the process by which phagosomes fuse sequentially with endosomes and lysosomes to acquire an acidic pH and hydrolases that degrade ingested particles. While the essential role of actin cytoskeleton remodeling during particle internalization is well established, its role during the later stages of phagosome maturation remains largely unknown. We have previously shown that purified mature phagosomes assemble F-actin at their membrane, and that the ezrin-radixin-moesin (ERM) proteins ezrin and moesin participate in this process. Moreover, we provided evidence that actin assembly on purified phagosomes stimulates their fusion with late endocytic compartments in vitro. In this study, we further investigated the role of ezrin in phagosome maturation. We engineered a structurally open form of ezrin and demonstrated that ezrin binds directly to the actin assembly promoting factor N-WASP (Neural Wiskott-Aldrich Syndrome Protein) by its FERM domain. Using a cell-free system, we found that ezrin stimulates F-actin assembly on purified phagosomes by recruiting the N-WASP-Arp2/3 machinery. Accordingly, we showed that the down-regulation of ezrin activity in macrophages by a dominant-negative approach caused reduced F-actin accumulation on maturing phagosomes. Furthermore, using fluorescence and electron microscopy, we found that ezrin is required for the efficient fusion between phagosomes and lysosomes. Live-cell imaging analysis supported the notion that ezrin is necessary for the fusogenic process itself, promoting the transfer of the lysosome content into the phagosomal lumen.
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Affiliation(s)
- Sabrina Marion
- Department of Cell Biology and Biophysics, European Molecular Biology Laboratory, Heidelberg, Germany.
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Letizia A, Sotillos S, Campuzano S, Llimargas M. Regulated Crb accumulation controls apical constriction and invagination in Drosophila tracheal cells. J Cell Sci 2010; 124:240-51. [PMID: 21172808 DOI: 10.1242/jcs.073601] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Many epithelial tissues undergo extensive remodelling during morphogenesis. How their epithelial features, such as apicobasal polarity or adhesion, are maintained and remodelled and how adhesion and polarity proteins contribute to morphogenesis are two important questions in development. Here, we approach these issues by investigating the role of the apical determinant protein Crumbs (Crb) during the morphogenesis of the embryonic Drosophila tracheal system. Crb accumulates differentially throughout tracheal development and is required for different tracheal events. The earliest requirement for Crb is for tracheal invagination, which is preceded by an enhanced accumulation of Crb in the invagination domain. There, Crb, acting in parallel with the epidermal growth factor receptor (Egfr) pathway, is required for tracheal cell apical constriction and for organising an actomyosin complex, which we propose is mediated by Crb recruitment of moesin (Moe). The ability of a Crb isoform unable to rescue polarity in crb mutants to otherwise rescue their invagination phenotype, and the converse inability of a FERM-binding domain mutant Crb to rescue faulty invagination, support our hypothesis that it is the absence of Crb-dependent Moe enrichment, and not the polarity defect, that mainly underlies the crb invagination phenotype. This hypothesis is supported by the phenotype of lethal giant larvae (lgl); crb double mutants. These results unveil a link between Crb and the organisation of the actin cytoskeleton during morphogenesis.
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Affiliation(s)
- Annalisa Letizia
- Institut de Biologia Molecular de Barcelona, CSIC, Parc Científic de Barcelona, Baldiri Reixac, 10-12, 08028 Barcelona, Spain
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Xu X, Omelchenko T, Hall A. LKB1 tumor suppressor protein regulates actin filament assembly through Rho and its exchange factor Dbl independently of kinase activity. BMC Cell Biol 2010; 11:77. [PMID: 20939895 PMCID: PMC2964536 DOI: 10.1186/1471-2121-11-77] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Accepted: 10/12/2010] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Germline mutations in LKB1 result in Peutz-Jeghers Syndrome characterized by intestinal hamartomas and increased incidence of epithelial cancers. LKB1 encodes a serine/threonine kinase that plays an important role in regulating energy metabolism through the AMPK/mTOR signaling pathway. In addition, LKB1 is homologous to PAR-4, a polarity protein first described in C. elegans, while activation of LKB1 in mammalian epithelial cells induces the polarized assembly of actin filaments. RESULTS To explore the mechanism by which LKB1 interacts with the actin cytoskeleton, we introduced LKB1 into HeLa cells that lack endogenous LKB1. This results in activation of the small GTPase Rho and the assembly of linear actin filaments associated with focal adhesions. These effects on the actin cytoskeleton are attenuated by siRNA-mediated depletion of the guanine nucleotide exchange factor Dbl. Co-expression of the LKB1 with the adaptor protein STRAD induces actin filament puncta associated with phospho-ezrin. CONCLUSIONS This study reveals that LKB1 regulates the actin cytoskeleton through a Dbl/Rho pathway.
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Affiliation(s)
- Xiaojian Xu
- Cell Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
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Baeyens N, Horman S, Vertommen D, Rider M, Morel N. Identification and functional implication of a Rho kinase-dependent moesin-EBP50 interaction in noradrenaline-stimulated artery. Am J Physiol Cell Physiol 2010; 299:C1530-40. [PMID: 20926777 DOI: 10.1152/ajpcell.00175.2010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ezrin, radixin, and moesin (ERM) proteins are known to be substrates of Rho kinase (ROCK), a key player in vascular smooth muscle regulation. Their function in arteries remains to be elucidated. The objective of the present study was to investigate ERM phosphorylation and function in rat aorta and mesenteric artery and the influence of ERM-binding phosphoprotein 50 (EBP50), a scaffold partner of ERM proteins in several cell types. In isolated arteries, ERM proteins are phosphorylated by PKC and ROCK with different kinetics after either agonist stimulation or KCl-induced depolarization. Immunoprecipitation of EBP50 in noradrenaline-stimulated arteries allowed identification of its interaction with moesin and several other proteins involved in cytoskeleton regulation. This interaction was inhibited by Y27632, a ROCK inhibitor. Moesin or EBP50 depletion after small interfering RNA transfection by reverse permeabilization in intact mesenteric arteries both potentiated the contractility in response to agonist stimulation without any effect on contractile response induced by high KCl. This effect was preserved in ionomycin-permeabilized arteries. These results indicate that, in agonist-stimulated arteries, the activation of ROCK leads to the binding of moesin to EBP50, which interacts with several components of the cytoskeleton, resulting in a decrease in the contractile response.
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Affiliation(s)
- Nicolas Baeyens
- Laboratory of Cell Physiology, Institute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium
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Wang Y, Kaiser MS, Larson JD, Nasevicius A, Clark KJ, Wadman SA, Roberg-Perez SE, Ekker SC, Hackett PB, McGrail M, Essner JJ. Moesin1 and Ve-cadherin are required in endothelial cells during in vivo tubulogenesis. Development 2010; 137:3119-28. [PMID: 20736288 DOI: 10.1242/dev.048785] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Endothelial tubulogenesis is a crucial step in the formation of functional blood vessels during angiogenesis and vasculogenesis. Here, we use in vivo imaging of living zebrafish embryos expressing fluorescent fusion proteins of beta-Actin, alpha-Catenin, and the ERM family member Moesin1 (Moesin a), to define a novel cord hollowing process that occurs during the initial stages of tubulogenesis in intersegmental vessels (ISVs) in the embryo. We show that the primary lumen elongates along cell junctions between at least two endothelial cells during embryonic angiogenesis. Moesin1-EGFP is enriched around structures that resemble intracellular vacuoles, which fuse with the luminal membrane during expansion of the primary lumen. Analysis of silent heart mutant embryos shows that initial lumen formation in the ISVs is not dependent on blood flow; however, stabilization of a newly formed lumen is dependent upon blood flow. Zebrafish moesin1 knockdown and cell transplantation experiments demonstrate that Moesin1 is required in the endothelial cells of the ISVs for in vivo lumen formation. Our analyses suggest that Moesin1 contributes to the maintenance of apical/basal cell polarity of the ISVs as defined by adherens junctions. Knockdown of the adherens junction protein Ve-cadherin disrupts formation of the apical membrane and lumen in a cell-autonomous manner. We suggest that Ve-cadherin and Moesin1 function to establish and maintain apical/basal polarity during multicellular lumen formation in the ISVs.
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Affiliation(s)
- Ying Wang
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA
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Portmann-Lanz CB, Schoeberlein A, Portmann R, Mohr S, Rollini P, Sager R, Surbek DV. Turning placenta into brain: placental mesenchymal stem cells differentiate into neurons and oligodendrocytes. Am J Obstet Gynecol 2010; 202:294.e1-294.e11. [PMID: 20060088 DOI: 10.1016/j.ajog.2009.10.893] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Revised: 08/14/2009] [Accepted: 10/29/2009] [Indexed: 12/23/2022]
Abstract
OBJECTIVE We aimed to induce neural stem (NSC) and progenitor cells (NPC) from human placental tissues. STUDY DESIGN Placental stem cells from first-trimester placental chorionic villi and term chorion were isolated. Neural differentiation was initiated with plating on collagen, retinoic acid, and/or human brain-derived neurotrophic factor and epidermal and fibroblast growth factor. Differentiation into neurons, oligodendrocytes, and astrocytes was monitored by immunohistochemistry. Two-dimensional polyacrylamide gel electrophoresis, high-performance liquid chromatography, and tandem mass spectrometry were used to identify proteins involved in the differentiation. RESULTS Differentiated cells were mostly immediately postmitotic with some more but not fully mature postmitotic neurons. Neurons had dopaminergic or serotonergic character. Some cells differentiated into predominantly immature oligodendrocytes. Upon differentiation, neuron-specific proteins were up-regulated, whereas placental proteins were reduced. CONCLUSION Stem cells derived from human placenta can be differentiated into neural progenitors.
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Moulding the shape of a metastatic cell. Leuk Res 2010; 34:843-7. [PMID: 20189645 DOI: 10.1016/j.leukres.2010.02.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Revised: 02/06/2010] [Accepted: 02/07/2010] [Indexed: 11/23/2022]
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Saarikangas J, Zhao H, Lappalainen P. Regulation of the actin cytoskeleton-plasma membrane interplay by phosphoinositides. Physiol Rev 2010; 90:259-89. [PMID: 20086078 DOI: 10.1152/physrev.00036.2009] [Citation(s) in RCA: 362] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The plasma membrane and the underlying cortical actin cytoskeleton undergo continuous dynamic interplay that is responsible for many essential aspects of cell physiology. Polymerization of actin filaments against cellular membranes provides the force for a number of cellular processes such as migration, morphogenesis, and endocytosis. Plasma membrane phosphoinositides (especially phosphatidylinositol bis- and trisphosphates) play a central role in regulating the organization and dynamics of the actin cytoskeleton by acting as platforms for protein recruitment, by triggering signaling cascades, and by directly regulating the activities of actin-binding proteins. Furthermore, a number of actin-associated proteins, such as BAR domain proteins, are capable of directly deforming phosphoinositide-rich membranes to induce plasma membrane protrusions or invaginations. Recent studies have also provided evidence that the actin cytoskeleton-plasma membrane interactions are misregulated in a number of pathological conditions such as cancer and during pathogen invasion. Here, we summarize the wealth of knowledge on how the cortical actin cytoskeleton is regulated by phosphoinositides during various cell biological processes. We also discuss the mechanisms by which interplay between actin dynamics and certain membrane deforming proteins regulate the morphology of the plasma membrane.
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Affiliation(s)
- Juha Saarikangas
- Program in Cell and Molecular Biology, Institute of Biotechnology, University of Helsinki, Helsinki, Finland
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Seeger TS, Frank D, Rohr C, Will R, Just S, Grund C, Lyon R, Luedde M, Koegl M, Sheikh F, Rottbauer W, Franke WW, Katus HA, Olson EN, Frey N. Myozap, a novel intercalated disc protein, activates serum response factor-dependent signaling and is required to maintain cardiac function in vivo. Circ Res 2010; 106:880-90. [PMID: 20093627 DOI: 10.1161/circresaha.109.213256] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
RATIONALE The intercalated disc (ID) is a highly specialized cell-cell contact structure that ensures mechanical and electric coupling of contracting cardiomyocytes. Recently, the ID has been recognized to be a hot spot of cardiac disease, in particular inherited cardiomyopathy. OBJECTIVE Given its complex structure and function we hypothesized that important molecular constituents of the ID still remain unknown. METHODS AND RESULTS Using a bioinformatics screen, we discovered and cloned a previously uncharacterized 54 kDa cardiac protein which we termed Myozap (Myocardium-enriched zonula occludens-1-associated protein). Myozap is strongly expressed in the heart and lung. In cardiac tissue it localized to the ID and directly binds to desmoplakin and zonula occludens-1. In a yeast 2-hybrid screen for additional binding partners of Myozap we identified myosin phosphatase-RhoA interacting protein (MRIP), a negative regulator of Rho activity. Myozap, in turn, strongly activates SRF-dependent transcription through its ERM (Ezrin/radixin/moesin)-like domain in a Rho-dependent fashion. Finally, in vivo knockdown of the Myozap ortholog in zebrafish led to severe contractile dysfunction and cardiomyopathy. CONCLUSIONS Taken together, these findings reveal Myozap as a previously unrecognized component of a Rho-dependent signaling pathway that links the intercalated disc to cardiac gene regulation. Moreover, its subcellular localization and the observation of a severe cardiac phenotype in zebrafish, implicate Myozap in the pathogenesis of cardiomyopathy.
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Affiliation(s)
- Thalia S Seeger
- Professor of Internal Medicine and Cardiology, Department of Cardiology and Angiology, University Hospital Schleswig-Holstein, Campus Kiel, Schittenhelmstr. 12, 24105 Kiel, Germany
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Grzendowski M, Wolter M, Riemenschneider MJ, Knobbe CB, Schlegel U, Meyer HE, Reifenberger G, Stühler K. Differential proteome analysis of human gliomas stratified for loss of heterozygosity on chromosomal arms 1p and 19q. Neuro Oncol 2010; 12:243-56. [PMID: 20167812 DOI: 10.1093/neuonc/nop025] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Combined deletion of chromosomal arms 1p and 19q is an independent prognostic marker in patients with oligodendroglial brain tumors, including oligodendrogliomas and oligoastrocytomas. However, the relevant genes in these chromosome arms and the molecular mechanisms underlying the prognostic significance of 1p/19q deletion are yet unknown. We used two-dimensional difference gel electrophoresis followed by mass spectrometry to perform a proteome-wide profiling of low-grade oligoastrocytomas stratified for the presence or absence of 1p/19q deletions. Thereby, we identified 22 different proteins showing differential expression in tumors with or without combined deletions of 1p and 19q. Four of the differentially expressed proteins, which are vimentin, villin 2 (ezrin), annexin A1, and glial fibrillary acidic protein, were selected for further analysis. Lower relative expression levels of these proteins in 1p/19q-deleted gliomas were confirmed at the protein level by Western blot analysis and immunohistochemistry. Furthermore, sequencing of sodium bisulfite-treated tumor DNA revealed more frequent methylation of 5'-CpG islands associated with the VIM and VIL2 genes in 1p/19q-deleted gliomas when compared with gliomas without these deletions. In summary, we confirm proteome-wide profiling as a powerful means to identify candidate biomarkers in gliomas. In addition, our data support the hypothesis that 1p/19q-deleted gliomas frequently show epigenetic down-regulation of multiple genes due to aberrant methylation of the 5'-CpG islands.
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Affiliation(s)
- Michael Grzendowski
- Medizinisches Proteom-Center, Ruhr-Universität Bochum, Universitätsstrasse 150, 44801 Bochum, Germany
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Live imaging reveals that the Drosophila actin-binding ERM protein, moesin, co-localizes with the mitotic spindle. Eur J Cell Biol 2009; 88:609-19. [DOI: 10.1016/j.ejcb.2009.05.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Revised: 05/13/2009] [Accepted: 05/19/2009] [Indexed: 01/11/2023] Open
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Estecha A, Sánchez-Martín L, Puig-Kröger A, Bartolomé RA, Teixidó J, Samaniego R, Sánchez-Mateos P. Moesin orchestrates cortical polarity of melanoma tumour cells to initiate 3D invasion. J Cell Sci 2009; 122:3492-501. [DOI: 10.1242/jcs.053157] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Tumour cell dissemination through corporal fluids (blood, lymph and body cavity fluids) is a distinctive feature of the metastatic process. Tumour cell transition from fluid to adhesive conditions involves an early polarization event and major rearrangements of the submembrane cytoskeleton that remain poorly understood. As regulation of cortical actin-membrane binding might be important in this process, we investigated the role of ezrin and moesin, which are key crosslinking proteins of the ERM (ezrin, radixin, moesin) family. We used short interfering RNA (siRNA) to show that moesin is crucial for invasion by melanoma cells in 3D matrices and in early lung colonization. Using live imaging, we show that following initial adhesion to the endothelium or 3D matrices, moesin is redistributed away from the region of adhesion, thereby generating a polarized cortex: a stable cortical actin dome enriched in moesin and an invasive membrane domain full of blebs. Using Lifeact-GFP, a 17-amino-acid peptide that binds F-actin, we show the initial symmetry breaking of cortical actin cytoskeleton during early attachment of round cells. We also demonstrated that ezrin and moesin are differentially distributed during initial invasion of 3D matrices, and, specifically, that moesin controls adhesion-dependent activation of Rho and subsequent myosin II contractility. Our results reveal that polarized moesin plays a role in orienting Rho activation, myosin II contractility, and cortical actin stability, which is crucial for driving directional vertical migration instead of superficial spreading on the fluid-to-solid tissue interface. We propose that this mechanism of cortical polarization could sustain extravasation of fluid-borne tumour cells during the process of metastasis.
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Affiliation(s)
- Ana Estecha
- Laboratorio de Inmuno-oncología, Hospital General Universitario Gregorio Marañón, 28007 Madrid, Spain
| | - Lorena Sánchez-Martín
- Laboratorio de Inmuno-oncología, Hospital General Universitario Gregorio Marañón, 28007 Madrid, Spain
| | - Amaya Puig-Kröger
- Laboratorio de Inmuno-oncología, Hospital General Universitario Gregorio Marañón, 28007 Madrid, Spain
| | - Rubén A. Bartolomé
- Department of Cellular and Molecular Physiopathology, Centro de Investigaciones Biológicas, 28040 Madrid, Spain
| | - Joaquín Teixidó
- Department of Cellular and Molecular Physiopathology, Centro de Investigaciones Biológicas, 28040 Madrid, Spain
| | - Rafael Samaniego
- Unidad de Microscopía Confocal, Hospital General Universitario Gregorio Marañón, 28007 Madrid, Spain
| | - Paloma Sánchez-Mateos
- Laboratorio de Inmuno-oncología, Hospital General Universitario Gregorio Marañón, 28007 Madrid, Spain
- Unidad de Microscopía Confocal, Hospital General Universitario Gregorio Marañón, 28007 Madrid, Spain
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42
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Kratochwill K, Lechner M, Siehs C, Lederhuber HC, Rehulka P, Endemann M, Kasper DC, Herkner KR, Mayer B, Rizzi A, Aufricht C. Stress responses and conditioning effects in mesothelial cells exposed to peritoneal dialysis fluid. J Proteome Res 2009; 8:1731-47. [PMID: 19231869 DOI: 10.1021/pr800916s] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Renal replacement therapy by peritoneal dialysis is frequently complicated by technical failure. Peritoneal dialysis fluids (PDF) cause injury to the peritoneal mesothelial cell layer due to their cytotoxicity. As only isolated elements of the involved cellular processes have been studied before, we aimed at a global assessment of the mesothelial stress response to PDF. Following single or repeated exposure to PDF or control medium, proteomics and bioinformatics techniques were combined to study effects in mesothelial cells (MeT-5A). Protein expression was assessed by two-dimensional gel electrophoresis, and significantly altered spots were identified by MALDI-TOF MS and MS2 techniques. The lists of experimentally derived candidate proteins were expanded by a next neighbor approach and analyzed for significantly enriched biological processes. To address the problem of an unknown portion of false positive spots in 2DGE, only proteins showing significant p-values on both levels were further interpreted. Single PDF exposure resulted in reduction of biological processes in favor of reparative responses, including protein metabolism, modification and folding, with chaperones as a major subgroup. The observed biological processes triggered by this acute PDF exposure mainly contained functionally interwoven multitasking proteins contributing as well to cytoskeletal reorganization and defense mechanisms. Repeated PDF exposure resulted in attenuated protein regulation, reflecting inhibition of stress responses by high levels of preinduced chaperones. The identified proteins were less attributable to acute cellular injury but rather to specialized functions with a reduced number of involved multitasking proteins. This finding agrees well with the concept of conditioning effects and cytoprotection. In conclusion, this study describes the reprogrammed proteome of mesothelial cells during recovery from PDF exposure and adaption to repetitive stress. A broad stress response with a number of highly overlapping processes and multitasking proteins shifts toward a more specific response of only few less overlapping processes.
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Affiliation(s)
- Klaus Kratochwill
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Austria
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43
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Froeling FEM, Mirza TA, Feakins RM, Seedhar A, Elia G, Hart IR, Kocher HM. Organotypic culture model of pancreatic cancer demonstrates that stromal cells modulate E-cadherin, beta-catenin, and Ezrin expression in tumor cells. THE AMERICAN JOURNAL OF PATHOLOGY 2009; 175:636-48. [PMID: 19608876 PMCID: PMC2716963 DOI: 10.2353/ajpath.2009.090131] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/15/2009] [Indexed: 12/21/2022]
Abstract
Pancreatic cancer is characterized by an intense stromal reaction. Reproducible three-dimensional in vitro systems for exploring interactions of the stroma with pancreatic cancer cells have not previously been available, prompting us to develop such a model. Cancer cells were grown on collagen/Matrigel and embedded with or without stromal cells (hTERT-immortalized human PS-1 stellate cells or MRC-5 fibroblasts) for 7 days. Proliferation and apoptosis, as well as important cell-cell adhesion and cytoskeleton-regulating proteins, were studied. PS-1 cells were confirmed as stellate based on the expression of key cytoskeletal proteins and lipid vesicles. Capan-1, and to a lesser extent PaCa-3, cells differentiated into luminal structures, exhibiting a central apoptotic core with a proliferating peripheral rim and an apico-basal polarity. Presence of either stromal cell type translocated Ezrin from apical (when stromal cells were absent) to basal aspects of cancer cells, where it was associated with invasive activity. Interestingly, the presence of 'normal' (not tumor-derived) stromal cells induced total tumor cell number reduction (P < 0.005) associated with a significant decrease in E-cadherin expression (P < 0.005). Conversely, beta-catenin expression was up-regulated (P < 0.01) in the presence of stromal cells with predominant cytoplasmic expression. Moreover, patient samples confirmed that these data recapitulated the clinical situation. In conclusion, pancreatic organotypic culture offers a reproducible, bio-mimetic, three-dimensional in vitro model that allows examination of the interactions between stromal elements and pancreatic cancer cells.
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Affiliation(s)
- Fieke E M Froeling
- Centre for Tumour Biology, Institute of Cancer, Barts and the London School of Medicine and Dentistry, Charterhouse Square, London EC1M 6BQ
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44
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Krawetz R, Kelly GM. Coordinate Gα13 and Wnt6-β-catenin signaling in F9 embryonal carcinoma cells is required for primitive endoderm differentiation. Biochem Cell Biol 2009; 87:567-80. [DOI: 10.1139/o09-014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The mouse F9 embryonal carcinoma cell line is ideally suited to study the epithelial-to-mesenchymal transition accompanying the differentiation of primitive to parietal extraembryonic endoderm. In F9 cells, the application of exogenous agents including retinoic acid or activation of signal transduction cascades downstream of G-proteins triggers widespread changes in gene expression and leads to the formation of primitive endoderm. The epithelial-to-mesenchymal transition is completed and parietal endoderm develops as of result of increasing PKA activity in primitive endoderm cells. Expression of a constitutively active form of Gα13(Q226L) is sufficient to induce F9 cells into parietal endoderm and a model is emerging that a signaling axis linking G-protein signaling to RhoA and the ERM protein moesin is required for differentiation. In this study, we found that expression of either p115RhoGEF or a constitutively active, GTPase-deficient form of RhoA(L63) promoted primitive, but not parietal, endoderm formation. The overexpression of Gα13(Q226L) or p115RhoGEF, but not Rho(L63), caused β-catenin to translocate to the nucleus. Surprisingly, the stimulation of the Wnt-β-catenin pathway was accompanied by nuclear β-catenin and primitive endoderm formation, even when a dominant negative was used to block the signaling axis at the level of p115RhoGEF or when ROCK activity was inhibited using the pharmacological agent Y-27632. Together, results indicate that the coordinate signaling by two independent pathways, one involving canonical Wnt-β-catenin activation of target genes and the other with Gα13 signaling to ERM proteins to modulate cytoarchitectural changes, is required during the retinoic acid induced differentiation of F9 cells to primitive endoderm.
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Affiliation(s)
- Roman Krawetz
- Department of Biology, Molecular Genetics Unit, University of Western Ontario, London, ON N6A 5B7, Canada
- Child Health Research Institute, University of Western Ontario, London, ON N6A 5B7, Canada
| | - Gregory M. Kelly
- Department of Biology, Molecular Genetics Unit, University of Western Ontario, London, ON N6A 5B7, Canada
- Child Health Research Institute, University of Western Ontario, London, ON N6A 5B7, Canada
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45
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FERM proteins in animal morphogenesis. Curr Opin Genet Dev 2009; 19:357-67. [PMID: 19596566 DOI: 10.1016/j.gde.2009.05.006] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2009] [Accepted: 05/29/2009] [Indexed: 01/19/2023]
Abstract
Proteins containing a FERM domain are ubiquitous components of the cytocortex of animal cells where they are engaged in structural, transport, and signaling functions. Recent years have seen a wealth of genetic studies in model organisms that explore FERM protein function in development and tissue organization. In addition, mutations in several FERM protein-encoding genes have been associated with human diseases. This review will provide a brief overview of the FERM domain structure and the FERM protein superfamily and then discuss recent advances in our understanding of the mechanism of function and developmental requirement of several FERM proteins including Moesin, Myosin-VIIA, Myosin-XV, Coracle/Band4.1 as well as Yurt and its vertebrate homologs Mosaic Eyes and EPB41L5/YMO1/Limulus.
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Di Sole F, Babich V, Moe OW. The calcineurin homologous protein-1 increases Na(+)/H(+) -exchanger 3 trafficking via ezrin phosphorylation. J Am Soc Nephrol 2009; 20:1776-86. [PMID: 19556366 DOI: 10.1681/asn.2008121255] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The Na(+)/H(+)-exchanger 3 (NHE3) is essential for regulation of Na(+) transport in the renal and intestinal epithelium. Although changes in cell surface abundance control NHE3 function, the molecular signals that regulate NHE3 surface expression are not well defined. We found that overexpression of the calcineurin homologous protein-1 (CHP1) in opossum kidney cells increased NHE3 transport activity, surface protein abundance, and ezrin phosphorylation. CHP1 knockdown by small interfering RNA had the opposite effects. Overexpression of wild-type ezrin increased both NHE3 transport activity and surface protein abundance, confirming that NHE3 is downstream of ezrin. Expression of a pseudophosphorylated ezrin enhanced these effects, whereas expression of an ezrin variant that could not be phosphorylated prevented the downstream effects on NHE3. Furthermore, CHP1 knockdown reversed the activation of NHE3 by wild-type ezrin but not by the pseudophosphorylated ezrin. Taken together, these results demonstrate that CHP1 increases NHE3 abundance and constitutive function in a manner dependent on ezrin phosphorylation.
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Affiliation(s)
- Francesca Di Sole
- Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-8885, USA.
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Espinoza JL, Takamatsu H, Lu X, Qi Z, Nakao S. Anti-moesin antibodies derived from patients with aplastic anemia stimulate monocytic cells to secrete TNF-alpha through an ERK1/2-dependent pathway. Int Immunol 2009; 21:913-23. [PMID: 19556303 DOI: 10.1093/intimm/dxp058] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Antibodies specific to moesin, which are frequently detectable in the serum of patients with aplastic anemia (AA), can induce tumor necrosis factor-alpha (TNF-alpha) secretion from monocytes and a human monocytic leukemia cell line THP-1. We investigated the mechanisms responsible for TNF-alpha secretion from monocytic cells induced by the auto-antibodies that are purified from the sera of AA patients. TNF-alpha induction by anti-moesin antibodies depended on the amount of cell surface moesin expressed by THP-1 cells. F(ab')(2) fragments prepared from the anti-moesin antibodies were able to stimulate THP-1 cells to secrete TNF-alpha and this stimulatory effect was enhanced by cross-linking of moesins with anti-human IgG F(ab')(2) fragment antibodies. Anti-moesin antibodies as well as their F(ab')(2) fragments induced the phosphorylation of ERK1/2 in monocytic cells and this effect was suppressed by the addition of an ERK1/2 inhibitor. Moreover, anti-moesin antibody treatment induced the phosphorylation of moesin proteins in the monocytes and THP-1 cells within 30 min. These results indicate that anti-moesin antibodies induce TNF-alpha secretion from monocytes through the activation of the ERK1/2 pathway provoked by direct binding to moesin on the cells.
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Affiliation(s)
- J Luis Espinoza
- Cellular Transplantation Biology, Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa, Japan
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48
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Abstract
The ability to form epithelial lumina is a central architectural characteristic of virtually all organs and indispensable for their function. Ontogenetically, the kidney is one of the best-characterized organs, but concepts of the regulated formation of its hollow epithelial structures are still emerging. Epithelial cell lines provide the opportunity to study molecular mechanisms in simplified assays modeling cyst and tube formation. In these systems, several groups have identified molecules implicated in lumen formation, and their downregulation results in either multiple-lumen or no-lumen phenotypes. On the basis of these phenotypes, we propose a working model, assigning proteins to groups with similar functions. Defects within these specific protein groups lead to distinct epithelial phenotypes. Studies of mesenchymal-to-epithelial transition underline the importance of these protein groups, but converting these basic models of lumen formation to an understanding of the mesenchymal to tubule formation during kidney development is still challenging.
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Affiliation(s)
- Marc A Schlüter
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA
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Abiatari I, Esposito I, Oliveira TD, Felix K, Xin H, Penzel R, Giese T, Friess H, Kleeff J. Moesin-dependent cytoskeleton remodelling is associated with an anaplastic phenotype of pancreatic cancer. J Cell Mol Med 2009; 14:1166-79. [PMID: 19432821 PMCID: PMC3822753 DOI: 10.1111/j.1582-4934.2009.00772.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Cell motility is controlled by the dynamic cytoskeleton and its related proteins, such as members of the ezrin/radixin/moesin (ERM) family, which act as signalling molecules inducing cytoskeleton remodelling. Although ERM proteins have been identified as important factors in various malignancies, functional redundancy between these proteins has hindered the dissection of their individual contribution. The aim of the present study was to analyse the functional role of moesin in pancreatic malignancies. Cancer cells of different malignant lesions of human and transgenic mice pancreata were evaluated by immunohistochemistry. For functional analysis, cell growth, adhesion and invasion assays were carried out after transient and stable knock-down of moesin expression in pancreatic cancer cells. In vivo tumourigenicity was determined using orthotopic and metastatic mouse tumour models. We now show that moesin knock-down increases migration, invasion and metastasis and influences extracellular matrix organization of pancreatic cancer. Moesin-regulated migratory activities of pancreatic cancer cells were in part promoted through cellular translocation of β-catenin, and re-distribution and organization of the cytoskeleton. Analysis of human and different transgenic mouse pancreatic cancers demonstrated that moesin is a phenotypic marker for anaplastic carcinoma, suggesting that this ERM protein plays a specific role in pancreatic carcinogenesis.
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Affiliation(s)
- Ivane Abiatari
- Department of General Surgery, Technische Universität München, Ismaningerstrasse 22, 81675 Munich, Germany
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50
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Niv MY, Iida K, Zheng R, Horiguchi A, Shen R, Nanus DM. Rational redesign of neutral endopeptidase binding to merlin and moesin proteins. Protein Sci 2009; 18:1042-50. [PMID: 19388049 DOI: 10.1002/pro.114] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Neutral endopeptidase (NEP) is a 90- to 110-kDa cell-surface peptidase that is normally expressed by numerous tissues but whose expression is lost or reduced in a variety of malignancies. The anti-tumorigenic function of NEP is mediated not only by its catalytic activity but also through direct protein-protein interactions of its cytosolic region with several binding partners, including Lyn kinase, PTEN, and ezrin/radixin/moesin (ERM) proteins. We have previously shown that mutation of the K(19)K(20)K(21) basic cluster in NEPs' cytosolic region to residues QNI disrupts binding to the ERM proteins. Here we show that the ERM-related protein merlin (NF2) does not bind NEP or its cytosolic region. Using experimental data, threading, and sequence analysis, we predicted the involvement of moesin residues E(159)Q(160) in binding to the NEP cytosolic domain. Mutation of these residues to NL (to mimic the corresponding N(159)L(160) residues in the nonbinder merlin) disrupted moesin binding to NEP. Mutation of residues N(159)L(160)Y(161)K(162)M(163) in merlin to the corresponding moesin residues resulted in NEP binding to merlin. This engineered NEP peptide-merlin interaction was diminished by the QNI mutation in NEP, supporting the role of the NEP basic cluster in binding. We thus identified the region of interaction between NEP and moesin, and engineered merlin into a NEP-binding protein. These data form the basis for further exploration of the details of NEP-ERM binding and function.
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Affiliation(s)
- Masha Y Niv
- Institute of Biochemistry, Food Science and Nutrition, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100, Israel
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