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Li M, Jiao Q, Xin W, Niu S, Liu M, Song Y, Wang Z, Yang X, Liang D. The Emerging Role of Rho Guanine Nucleotide Exchange Factors in Cardiovascular Disorders: Insights Into Atherosclerosis: A Mini Review. Front Cardiovasc Med 2022; 8:782098. [PMID: 35047576 PMCID: PMC8761945 DOI: 10.3389/fcvm.2021.782098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 11/18/2021] [Indexed: 11/13/2022] Open
Abstract
Atherosclerosis is a leading cause of cardiovascular disease, and atherosclerotic cardiovascular disease accounts for one-third of global deaths. However, the mechanism of atherosclerosis is not fully understood. It is well-known that the Rho GTPase family, especially Rho A, plays a vital role in the development and progression of arteriosclerosis. Rho guanine nucleotide exchange factors (Rho GEFs), which act upstream of Rho GTPases, are also involved in the atheromatous pathological process. Despite some research on the role of Rho GEFS in the regulation of atherosclerosis, the number of studies is small relative to studies on the essential function of Rho GEFs. Some studies have preliminarily revealed Rho GEF regulation of atherosclerosis by experiments in vivo and in vitro. Herein, we review the advances in research on the relationship and interaction between Rho GEFs and atheroma to provide a potential reference for further study of atherosclerosis.
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Affiliation(s)
- Mengqi Li
- Department of Cardiovascular Surgery, Tianjin Medical University General Hospital, Tianjin, China
| | - Qingzheng Jiao
- Second Department of Internal Medicine, Gucheng County Hospital, Hengshui Gucheng, Hebei, China
| | - Wenqiang Xin
- Department of Neurology, University of Göttingen Medical School, Göttingen, Germany
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China
| | - Shulin Niu
- Department of Cardiology, Tianjin Medical University General Hospital, Tianjin, China
| | - Mingming Liu
- Department of Neurology and Immunology, Institute of Neurology, Tianjin Medical University General Hospital, Tianjin, China
| | - Yanxin Song
- Department of Nursing, Tianjin Medical University, Tianjin, China
| | - Zengguang Wang
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China
- Zengguang Wang
| | - Xinyu Yang
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China
- Xinyu Yang
| | - Degang Liang
- Department of Cardiovascular Surgery, Tianjin Medical University General Hospital, Tianjin, China
- *Correspondence: Degang Liang
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Khan A, Ni W, Lopez-Giraldez F, Kluger MS, Pober JS, Pierce RW. Tumor necrosis factor-induced ArhGEF10 selectively activates RhoB contributing to human microvascular endothelial cell tight junction disruption. FASEB J 2021; 35:e21627. [PMID: 33948992 DOI: 10.1096/fj.202002783rr] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 04/07/2021] [Accepted: 04/13/2021] [Indexed: 12/31/2022]
Abstract
Capillary endothelial cells (ECs) maintain a semi-permeable barrier between the blood and tissue by forming inter-EC tight junctions (TJs), regulating selective transport of fluid and solutes. Overwhelming inflammation, as occurs in sepsis, disrupts these TJs, leading to leakage of fluid, proteins, and small molecules into the tissues. Mechanistically, disruption of capillary barrier function is mediated by small Rho-GTPases, such as RhoA, -B, and -C, which are activated by guanine nucleotide exchange factors (GEFs) and disrupted by GTPase-activating factors (GAPs). We previously reported that a mutation in a specific RhoB GAP (p190BRhoGAP) underlays a hereditary capillary leak syndrome. Tumor necrosis factor (TNF) treatment disrupts TJs in cultured human microvascular ECs, a model of capillary leak. This response requires new gene transcription and involves increased RhoB activation. However, the specific GEF that activates RhoB in capillary ECs remains unknown. Transcriptional profiling of cultured tight junction-forming human dermal microvascular endothelial cells (HDMECs) revealed that 17 GEFs were significantly induced by TNF. The function of each candidate GEF was assessed by short interfering RNA depletion and trans-endothelial electrical resistance screening. Knockown of ArhGEF10 reduced the TNF-induced loss of barrier which was phenocopied by RhoB or dual ArhGEF10/RhoB knockdown. ArhGEF10 knockdown also reduced the extent of TNF-induced RhoB activation and disruption at tight junctions. In a cell-free assay, immunoisolated ArhGEF10 selectively catalyzed nucleotide exchange to activate RhoB, but not RhoA or RhoC. We conclude ArhGEF10 is a TNF-induced RhoB-selective GEF that mediates TJ disruption and barrier loss in human capillary endothelial cells.
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Affiliation(s)
- Alamzeb Khan
- Department of Pediatrics, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Weiming Ni
- Department of Pediatrics, Yale School of Medicine, Yale University, New Haven, CT, USA
| | | | - Martin S Kluger
- Department of Immunobiology, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Jordan S Pober
- Department of Immunobiology, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Richard W Pierce
- Department of Pediatrics, Yale School of Medicine, Yale University, New Haven, CT, USA
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Weber P, Baltus D, Jatho A, Drews O, Zelarayan LC, Wieland T, Lutz S. RhoGEF17-An Essential Regulator of Endothelial Cell Death and Growth. Cells 2021; 10:cells10040741. [PMID: 33801779 PMCID: PMC8067313 DOI: 10.3390/cells10040741] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 03/15/2021] [Accepted: 03/20/2021] [Indexed: 12/18/2022] Open
Abstract
The Rho guanine nucleotide exchange factor RhoGEF17 was described to reside in adherens junctions (AJ) in endothelial cells (EC) and to play a critical role in the regulation of cell adhesion and barrier function. The purpose of this study was to analyze signal cascades and processes occurring subsequent to AJ disruption induced by RhoGEF17 knockdown. Primary human and immortalized rat EC were used to demonstrate that an adenoviral-mediated knockdown of RhoGEF17 resulted in cell rounding and an impairment in spheroid formation due to an enhanced proteasomal degradation of AJ components. In contrast, β-catenin degradation was impaired, which resulted in an induction of the β-catenin-target genes cyclin D1 and survivin. RhoGEF17 depletion additionally inhibited cell adhesion and sheet migration. The RhoGEF17 knockdown prevented the cells with impeded cell–cell and cell–matrix contacts from apoptosis, which was in line with a reduction in pro-caspase 3 expression and an increase in Akt phosphorylation. Nevertheless, the cells were not able to proliferate as a cell cycle block occurred. In summary, we demonstrate that a loss of RhoGEF17 disturbs cell–cell and cell–substrate interaction in EC. Moreover, it prevents the EC from cell death and blocks cell proliferation. Non-canonical β-catenin signaling and Akt activation could be identified as a potential mechanism.
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Affiliation(s)
- Pamina Weber
- Experimental Pharmacology Mannheim (EPM), European Center for Angioscience (ECAS), Medical Faculty Mannheim, Heidelberg University, Ludolf-Krehl-Str. 13-17, 68167 Mannheim, Germany; (P.W.); (D.B.)
| | - Doris Baltus
- Experimental Pharmacology Mannheim (EPM), European Center for Angioscience (ECAS), Medical Faculty Mannheim, Heidelberg University, Ludolf-Krehl-Str. 13-17, 68167 Mannheim, Germany; (P.W.); (D.B.)
| | - Aline Jatho
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Robert-Koch-Strasse 40, 37075 Göttingen, Germany; (A.J.); (L.C.Z.)
- DZHK (German Center for Cardiovascular Research) Partner Site Göttingen, Göttingen, Germany
| | - Oliver Drews
- Institute for Clinical Chemistry, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany;
| | - Laura C. Zelarayan
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Robert-Koch-Strasse 40, 37075 Göttingen, Germany; (A.J.); (L.C.Z.)
- DZHK (German Center for Cardiovascular Research) Partner Site Göttingen, Göttingen, Germany
| | - Thomas Wieland
- Experimental Pharmacology Mannheim (EPM), European Center for Angioscience (ECAS), Medical Faculty Mannheim, Heidelberg University, Ludolf-Krehl-Str. 13-17, 68167 Mannheim, Germany; (P.W.); (D.B.)
- DZHK (German Center for Cardiovascular Research) Partner Site Heidelberg/Mannheim, Mannheim, Germany
- Correspondence: (T.W.); (S.L.)
| | - Susanne Lutz
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Robert-Koch-Strasse 40, 37075 Göttingen, Germany; (A.J.); (L.C.Z.)
- DZHK (German Center for Cardiovascular Research) Partner Site Göttingen, Göttingen, Germany
- Correspondence: (T.W.); (S.L.)
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Saffioti NA, Cavalcanti-Adam EA, Pallarola D. Biosensors for Studies on Adhesion-Mediated Cellular Responses to Their Microenvironment. Front Bioeng Biotechnol 2020; 8:597950. [PMID: 33262979 PMCID: PMC7685988 DOI: 10.3389/fbioe.2020.597950] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Accepted: 10/12/2020] [Indexed: 12/28/2022] Open
Abstract
Cells interact with their microenvironment by constantly sensing mechanical and chemical cues converting them into biochemical signals. These processes allow cells to respond and adapt to changes in their environment, and are crucial for most cellular functions. Understanding the mechanism underlying this complex interplay at the cell-matrix interface is of fundamental value to decipher key biochemical and mechanical factors regulating cell fate. The combination of material science and surface chemistry aided in the creation of controllable environments to study cell mechanosensing and mechanotransduction. Biologically inspired materials tailored with specific bioactive molecules, desired physical properties and tunable topography have emerged as suitable tools to study cell behavior. Among these materials, synthetic cell interfaces with built-in sensing capabilities are highly advantageous to measure biophysical and biochemical interaction between cells and their environment. In this review, we discuss the design of micro and nanostructured biomaterials engineered not only to mimic the structure, properties, and function of the cellular microenvironment, but also to obtain quantitative information on how cells sense and probe specific adhesive cues from the extracellular domain. This type of responsive biointerfaces provides a readout of mechanics, biochemistry, and electrical activity in real time allowing observation of cellular processes with molecular specificity. Specifically designed sensors based on advanced optical and electrochemical readout are discussed. We further provide an insight into the emerging role of multifunctional micro and nanosensors to control and monitor cell functions by means of material design.
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Affiliation(s)
- Nicolás Andrés Saffioti
- Instituto de Nanosistemas, Universidad Nacional de General San Martín, San Martín, Argentina
| | | | - Diego Pallarola
- Instituto de Nanosistemas, Universidad Nacional de General San Martín, San Martín, Argentina
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AP-1 and TGFß cooperativity drives non-canonical Hedgehog signaling in resistant basal cell carcinoma. Nat Commun 2020; 11:5079. [PMID: 33033234 PMCID: PMC7546632 DOI: 10.1038/s41467-020-18762-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 09/01/2020] [Indexed: 12/17/2022] Open
Abstract
Tumor heterogeneity and lack of knowledge about resistant cell states remain a barrier to targeted cancer therapies. Basal cell carcinomas (BCCs) depend on Hedgehog (Hh)/Gli signaling, but can develop mechanisms of Smoothened (SMO) inhibitor resistance. We previously identified a nuclear myocardin-related transcription factor (nMRTF) resistance pathway that amplifies noncanonical Gli1 activity, but characteristics and drivers of the nMRTF cell state remain unknown. Here, we use single cell RNA-sequencing of patient tumors to identify three prognostic surface markers (LYPD3, TACSTD2, and LY6D) which correlate with nMRTF and resistance to SMO inhibitors. The nMRTF cell state resembles transit-amplifying cells of the hair follicle matrix, with AP-1 and TGFß cooperativity driving nMRTF activation. JNK/AP-1 signaling commissions chromatin accessibility and Smad3 DNA binding leading to a transcriptional program of RhoGEFs that facilitate nMRTF activity. Importantly, small molecule AP-1 inhibitors selectively target LYPD3+/TACSTD2+/LY6D+ nMRTF human BCCs ex vivo, opening an avenue for improving combinatorial therapies.
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Influence of Endogenous Cardiac Glycosides, Digoxin, and Marinobufagenin in the Physiology of Epithelial Cells. Cardiol Res Pract 2019; 2019:8646787. [PMID: 32089875 PMCID: PMC7024086 DOI: 10.1155/2019/8646787] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 09/20/2019] [Accepted: 11/15/2019] [Indexed: 12/14/2022] Open
Abstract
Cardiac glycosides are a group of compounds widely known for their action in cardiac tissue, some of which have been found to be endogenously produced (ECG). We have previously studied the effect of ouabain, an endogenous cardiac glycoside, on the physiology of epithelial cells, and we have shown that in concentrations in the nanomolar range, it affects key properties of epithelial cells, such as tight junction, apical basolateral polarization, gap junctional intercellular communication (GJIC), and adherent junctions. In this work, we study the influence of digoxin and marinobufagenin, two other endogenously expressed cardiac glycosides, on GJIC as well as the degree of transepithelial tightness due to tight junction integrity (TJ). We evaluated GJIC by dye transfer assays and tight junction integrity by transepithelial electrical resistance (TER) measurements, as well as immunohistochemistry and western blot assays of expression of claudins 2 and 4. We found that both digoxin and marinobufagenin improve GJIC and significantly enhance the tightness of the tight junctions, as evaluated from TER measurements. Immunofluorescence assays show that both compounds promote enhanced basolateral localization of claudin-4 but not claudin 2, while densitometric analysis of western blot assays indicate a significantly increased expression of claudin 4. These changes, induced by digoxin and marinobufagenin on GJIC and TER, were not observed on MDCK-R, a modified MDCK cell line that has a genetically induced insensitive α1 subunit, indicating that Na-K-ATPase acts as a receptor mediating the actions of both ECG. Plus, the fact that the effect of both cardiac glycosides was suppressed by incubation with PP2, an inhibitor of c-Src kinase, PD98059, an inhibitor of mitogen extracellular kinase-1 and Y-27632, a selective inhibitor of ROCK, and a Rho-associated protein kinase, indicate altogether that the signaling pathways involved include c-Src and ERK1/2, as well as Rho-ROCK. These results widen and strengthen our general hypothesis that a very important physiological role of ECG is the control of the epithelial phenotype and the regulation of cell-cell contacts.
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Shigetomi K, Ikenouchi J. Cell Adhesion Structures in Epithelial Cells Are Formed in Dynamic and Cooperative Ways. Bioessays 2019; 41:e1800227. [PMID: 31187900 DOI: 10.1002/bies.201800227] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 04/16/2019] [Indexed: 01/13/2023]
Abstract
There are many morphologically distinct membrane structures with different functions at the surface of epithelial cells. Among these, adherens junctions (AJ) and tight junctions (TJ) are responsible for the mechanical linkage of epithelial cells and epithelial barrier function, respectively. In the process of new cell-cell adhesion formation between two epithelial cells, such as after wounding, AJ form first and then TJ form on the apical side of AJ. This process is very complicated because AJ formation triggers drastic changes in the organization of actin cytoskeleton, the activity of Rho family of small GTPases, and the lipid composition of the plasma membrane, all of which are required for subsequent TJ formation. In this review, the authors focus on the relationship between AJ and TJ as a representative example of specialization of plasma membrane regions and introduce recent findings on how AJ formation promotes the subsequent formation of TJ.
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Affiliation(s)
- Kenta Shigetomi
- Department of Biology, Faculty of Sciences, Kyushu University, 774 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Junichi Ikenouchi
- Department of Biology, Faculty of Sciences, Kyushu University, 774 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.,Japan Science and Technology Agency, Saitama, 332-0012, Japan.,AMED-PRIME, Japan Agency for Medical Research and Development, Tokyo, 100-0004, Japan
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Aktories K, Gierschik P, Heringdorf DMZ, Schmidt M, Schultz G, Wieland T. cAMP guided his way: a life for G protein-mediated signal transduction and molecular pharmacology-tribute to Karl H. Jakobs. Naunyn Schmiedebergs Arch Pharmacol 2019; 392:887-911. [PMID: 31101932 DOI: 10.1007/s00210-019-01650-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 04/02/2019] [Indexed: 12/14/2022]
Abstract
Karl H. Jakobs, former editor-in-chief of Naunyn-Schmiedeberg's Archives of Pharmacology and renowned molecular pharmacologist, passed away in April 2018. In this article, his scientific achievements regarding G protein-mediated signal transduction and regulation of canonical pathways are summarized. Particularly, the discovery of inhibitory G proteins for adenylyl cyclase, methods for the analysis of receptor-G protein interactions, GTP supply by nucleoside diphosphate kinases, mechanisms in phospholipase C and phospholipase D activity regulation, as well as the development of the concept of sphingosine-1-phosphate as extra- and intracellular messenger will presented. His seminal scientific and methodological contributions are put in a general and timely perspective to display and honor his outstanding input to the current knowledge in molecular pharmacology.
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Affiliation(s)
- Klaus Aktories
- Institute for Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert Ludwigs University, 79104, Freiburg, Germany
| | - Peter Gierschik
- Institute of Pharmacology and Toxicology, Ulm University Medical Center, 89070, Ulm, Germany
| | - Dagmar Meyer Zu Heringdorf
- Institute of General Pharmacology and Toxicology, University Hospital Frankfurt am Main, Goethe University, 60590, Frankfurt am Main, Germany
| | - Martina Schmidt
- Department of Molecular Pharmacology, University of Groningen, 9713AV, Groningen, The Netherlands
| | - Günter Schultz
- Department of Pharmacology, Charité University Medical Center Berlin, Campus Benjamin Franklin, 14195, Berlin, Germany
| | - Thomas Wieland
- Experimental Pharmacology Mannheim (EPM), European Center for Angioscience (ECAS), Medical Faculty Mannheim, Heidelberg University, Ludolf-Krehl-Str. 13 - 17, 68167, Mannheim, Germany.
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Braga V. Signaling by Small GTPases at Cell-Cell Junctions: Protein Interactions Building Control and Networks. Cold Spring Harb Perspect Biol 2018; 10:cshperspect.a028746. [PMID: 28893858 DOI: 10.1101/cshperspect.a028746] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
A number of interesting reports highlight the intricate network of signaling proteins that coordinate formation and maintenance of cell-cell contacts. We have much yet to learn about how the in vitro binding data is translated into protein association inside the cells and whether such interaction modulates the signaling properties of the protein. What emerges from recent studies is the importance to carefully consider small GTPase activation in the context of where its activation occurs, which upstream regulators are involved in the activation/inactivation cycle and the GTPase interacting partners that determine the intracellular niche and extent of signaling. Data discussed here unravel unparalleled cooperation and coordination of functions among GTPases and their regulators in supporting strong adhesion between cells.
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Affiliation(s)
- Vania Braga
- Molecular Medicine, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, London SW7 2AZ, United Kingdom
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He L, Pierce RW, Min W. Rare and Low-Frequency Variant of ARHGEF17 Is Associated With Intracranial Aneurysms. CIRCULATION. GENOMIC AND PRECISION MEDICINE 2018; 11:e002248. [PMID: 29997229 PMCID: PMC6082391 DOI: 10.1161/circgen.118.002248] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Li He
- Center for Translational Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China (L.H., W.M.)
| | - Richard W Pierce
- The Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, CT (R.W.P., W.M.)
| | - Wang Min
- Center for Translational Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China (L.H., W.M.).
- The Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, CT (R.W.P., W.M.)
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Yang X, Li J, Fang Y, Zhang Z, Jin D, Chen X, Zhao Y, Li M, Huan L, Kent TA, Dong JF, Jiang R, Yang S, Jin L, Zhang J, Zhong TP, Yu F. Rho Guanine Nucleotide Exchange Factor ARHGEF17 Is a Risk Gene for Intracranial Aneurysms. CIRCULATION. GENOMIC AND PRECISION MEDICINE 2018; 11:e002099. [PMID: 29997225 PMCID: PMC6141028 DOI: 10.1161/circgen.117.002099] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 05/22/2018] [Indexed: 11/16/2022]
Abstract
BACKGROUND Intracranial aneurysm (IA) is usually a late-onset disease, affecting 1% to 3% of the general population and leading to life-threatening subarachnoid hemorrhage. Genetic susceptibility has been implicated in IAs, but the causative genes remain elusive. METHODS We performed next-generation sequencing in a discovery cohort of 20 Chinese IA patients. Bioinformatics filters were exploited to search for candidate deleterious variants with rare and low allele frequency. We further examined the candidate variants in a multiethnic sample collection of 86 whole exome sequenced unsolved familial IA cases from 3 previously published studies. RESULTS We identified that the low-frequency variant c.4394C>A_p.Ala1465Asp (rs2298808) of ARHGEF17 was significantly associated with IA in our Chinese discovery cohort (P=7.3×10-4; odds ratio=7.34). It was subsequently replicated in Japanese familial IA patients (P=0.039; odds ratio=4.00; 95% confidence interval=0.832-14.8) and was associated with IA in the large Chinese sample collection comprising 832 sporadic IA-affected and 599 control individuals (P=0.041; odds ratio=1.51; 95% confidence interval=1.02-Inf). When combining the sequencing data of all familial IA patients from 4 different ethnicities (ie, Chinese, Japanese, European American, and French-Canadian), we identified a significantly increased mutation burden for ARHGEF17 (21/106 versus 11/306; P=8.1×10-7; odds ratio=6.6; 95% confidence interval=2.9-15.8) in cases as compared with controls. In zebrafish, arhgef17 was highly expressed in the brain blood vessel. arhgef17 knockdown caused blood extravasation in the brain region. Endothelial lesions were identified exclusively on cerebral blood vessels in the arhgef17-deficient zebrafish. CONCLUSIONS Our results provide compelling evidence that ARHGEF17 is a risk gene for IA.
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Affiliation(s)
- Xinyu Yang
- Department of Neurosurgery, Tianjin Neurological Institute, Tianjin Medical University General Hospital, China (X.Y., Z.Z., Y.Z., M.L., L.H., R.J., S.Y., J.Z., F.Y.)
| | - Jiani Li
- Human Genome Sequencing Center, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX (J.L., F.Y.)
| | - Yabo Fang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhong Shan Hospital, Fudan University, Shanghai, China (Y.F., D.J., X.C., L.J., T.P.Z.)
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences (Y.F., D.J., L.J., T.P.Z.)
| | - Zhen Zhang
- Department of Neurosurgery, Tianjin Neurological Institute, Tianjin Medical University General Hospital, China (X.Y., Z.Z., Y.Z., M.L., L.H., R.J., S.Y., J.Z., F.Y.)
| | - Daqing Jin
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhong Shan Hospital, Fudan University, Shanghai, China (Y.F., D.J., X.C., L.J., T.P.Z.)
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences (Y.F., D.J., L.J., T.P.Z.)
| | - Xingdong Chen
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhong Shan Hospital, Fudan University, Shanghai, China (Y.F., D.J., X.C., L.J., T.P.Z.)
| | - Yan Zhao
- Department of Neurosurgery, Tianjin Neurological Institute, Tianjin Medical University General Hospital, China (X.Y., Z.Z., Y.Z., M.L., L.H., R.J., S.Y., J.Z., F.Y.)
| | - Mengqi Li
- Department of Neurosurgery, Tianjin Neurological Institute, Tianjin Medical University General Hospital, China (X.Y., Z.Z., Y.Z., M.L., L.H., R.J., S.Y., J.Z., F.Y.)
| | - Linchun Huan
- Department of Neurosurgery, Tianjin Neurological Institute, Tianjin Medical University General Hospital, China (X.Y., Z.Z., Y.Z., M.L., L.H., R.J., S.Y., J.Z., F.Y.)
- Department of Neurosurgery, Linyi People's Hospital, Shandong, China (L.H.)
| | - Thomas A Kent
- Engineering Medicine, Texas A&M Health Science Center and College of Engineering, Houston (T.A.K.)
| | - Jing-Fei Dong
- Blood Works Northwest Research Institute, Seattle, WA (J.-F.D.)
- Division of Hematology, Department of Medicine, University of Washington School of Medicine, Seattle (J.-F.D.)
| | - Rongcai Jiang
- Department of Neurosurgery, Tianjin Neurological Institute, Tianjin Medical University General Hospital, China (X.Y., Z.Z., Y.Z., M.L., L.H., R.J., S.Y., J.Z., F.Y.)
| | - Shuyuan Yang
- Department of Neurosurgery, Tianjin Neurological Institute, Tianjin Medical University General Hospital, China (X.Y., Z.Z., Y.Z., M.L., L.H., R.J., S.Y., J.Z., F.Y.)
| | - Li Jin
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhong Shan Hospital, Fudan University, Shanghai, China (Y.F., D.J., X.C., L.J., T.P.Z.)
| | - Jianning Zhang
- Department of Neurosurgery, Tianjin Neurological Institute, Tianjin Medical University General Hospital, China (X.Y., Z.Z., Y.Z., M.L., L.H., R.J., S.Y., J.Z., F.Y.).
| | - Tao P Zhong
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhong Shan Hospital, Fudan University, Shanghai, China (Y.F., D.J., X.C., L.J., T.P.Z.).
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences (Y.F., D.J., L.J., T.P.Z.)
| | - Fuli Yu
- Department of Neurosurgery, Tianjin Neurological Institute, Tianjin Medical University General Hospital, China (X.Y., Z.Z., Y.Z., M.L., L.H., R.J., S.Y., J.Z., F.Y.).
- Human Genome Sequencing Center, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX (J.L., F.Y.)
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12
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Kwasnik A, von Kriegsheim A, Irving A, Pennington SR. Potential mechanisms of calcium dependent regulation of the mammalian cell cycle revealed by comprehensive unbiased label-free nLC-MS/MS quantitative proteomics. J Proteomics 2018; 170:151-166. [DOI: 10.1016/j.jprot.2017.08.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 08/03/2017] [Accepted: 08/05/2017] [Indexed: 01/27/2023]
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Radeva MY, Waschke J. Mind the gap: mechanisms regulating the endothelial barrier. Acta Physiol (Oxf) 2018; 222. [PMID: 28231640 DOI: 10.1111/apha.12860] [Citation(s) in RCA: 161] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 11/21/2016] [Accepted: 02/16/2017] [Indexed: 12/11/2022]
Abstract
The endothelial barrier consists of intercellular contacts localized in the cleft between endothelial cells, which is covered by the glycocalyx in a sievelike manner. Both types of barrier-forming junctions, i.e. the adherens junction (AJ) serving mechanical anchorage and mechanotransduction and the tight junction (TJ) sealing the intercellular space to limit paracellular permeability, are tethered to the actin cytoskeleton. Under resting conditions, the endothelium thereby builds a selective layer controlling the exchange of fluid and solutes with the surrounding tissue. However, in the situation of an inflammatory response such as in anaphylaxis or sepsis intercellular contacts disintegrate in post-capillary venules leading to intercellular gap formation. The resulting oedema can cause shock and multi-organ failure. Therefore, maintenance as well as coordinated opening and closure of interendothelial junctions is tightly regulated. The two principle underlying mechanisms comprise spatiotemporal activity control of the small GTPases Rac1 and RhoA and the balance of the phosphorylation state of AJ proteins. In the resting state, junctional Rac1 and RhoA activity is enhanced by junctional components, actin-binding proteins, cAMP signalling and extracellular cues such as sphingosine-1-phosphate (S1P) and angiopoietin-1 (Ang-1). In addition, phosphorylation of AJ components is prevented by junction-associated phosphatases including vascular endothelial protein tyrosine phosphatase (VE-PTP). In contrast, inflammatory mediators inhibiting cAMP/Rac1 signalling cause strong activation of RhoA and induce AJ phosphorylation finally leading to endocytosis and cleavage of VE-cadherin. This results in dissolution of TJs the outcome of which is endothelial barrier breakdown.
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Affiliation(s)
- M. Y. Radeva
- Institute of Anatomy and Cell Biology; Ludwig-Maximilians-Universität München; Munich Germany
| | - J. Waschke
- Institute of Anatomy and Cell Biology; Ludwig-Maximilians-Universität München; Munich Germany
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Biomarkers Discovery for Colorectal Cancer: A Review on Tumor Endothelial Markers as Perspective Candidates. DISEASE MARKERS 2016; 2016:4912405. [PMID: 27965519 PMCID: PMC5124654 DOI: 10.1155/2016/4912405] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Revised: 10/02/2016] [Accepted: 10/16/2016] [Indexed: 02/07/2023]
Abstract
Colorectal cancer (CRC) is the third most common cancer in the world. The early detection of CRC, during the promotion/progression stages, is an enormous challenge for a successful outcome and remains a fundamental problem in clinical approach. Despite the continuous advancement in diagnostic and therapeutic methods, there is a need for discovery of sensitive and specific, noninvasive biomarkers. Tumor endothelial markers (TEMs) are associated with tumor-specific angiogenesis and are potentially useful to discriminate between tumor and normal endothelium. The most promising TEMs for oncogenic signaling in CRC appeared to be the TEM1, TEM5, TEM7, and TEM8. Overexpression of TEMs especially TEM1, TEM7, and TEM8 in colorectal tumor tissue compared to healthy tissue suggests their role in tumor blood vessels formation. Thus TEMs appear to be perspective candidates for early detection, monitoring, and treatment of CRC patients. This review provides an update on recent data on tumor endothelial markers and their possible use as biomarkers for screening, diagnosis, and therapy of colorectal cancer patients.
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Otsu K, Ida-Yonemochi H, Fujiwara N, Harada H. The Semaphorin 4D-RhoA-Akt Signal Cascade Regulates Enamel Matrix Secretion in Coordination With Cell Polarization During Ameloblast Differentiation. J Bone Miner Res 2016; 31:1943-1954. [PMID: 27218883 DOI: 10.1002/jbmr.2876] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 05/19/2016] [Accepted: 05/20/2016] [Indexed: 11/08/2022]
Abstract
During tooth development, oral epithelial cells differentiate into ameloblasts in order to form the most mineralized tissue in the vertebrate body: enamel. During this process, ameloblasts directionally secrete enamel matrix proteins and morphologically change from low columnar cells to polarized tall columnar cells, both of which are essential for the proper formation of enamel. In this study, we elucidated the molecular mechanism that integrates ameloblast function and morphology. Immunohistochemistry revealed that the restricted expression of semaphorin 4D (Sema4D) and RhoA activation status are closely associated with ameloblast differentiation in mouse incisors. In addition, in vitro gain-of-function and loss-of-function experiments demonstrated that Sema4D acts upstream of RhoA to regulate cell polarity and amelogenin expression via the Plexin B1/Leukemia-associated RhoGEF (LARG) complex during ameloblast differentiation. Experiments in transgenic mice demonstrated that expression of a dominant-negative form of RhoA in dental epithelium hindered ameloblast differentiation and subsequent enamel formation, as well as perturbing the establishment of polarized cell morphology and vectorial amelogenin expression. Finally, we showed that spatially restricted Akt mediates between Sema4D-RhoA signaling and these downstream cellular events. Collectively, our results reveal a novel signaling network, the Sema4D-RhoA-Akt signal cascade, that coordinates cellular function and morphology and highlights the importance of specific spatiotemporally restricted components of a signaling pathway in the regulation of ameloblast differentiation. © 2016 American Society for Bone and Mineral Research.
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Affiliation(s)
- Keishi Otsu
- Division of Developmental Biology and Regenerative Medicine, Department of Anatomy, Iwate Medical University, Iwate, Japan
| | - Hiroko Ida-Yonemochi
- Division of Anatomy and Cell Biology of the Hard Tissue, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Naoki Fujiwara
- Division of Developmental Biology and Regenerative Medicine, Department of Anatomy, Iwate Medical University, Iwate, Japan
| | - Hidemitsu Harada
- Division of Developmental Biology and Regenerative Medicine, Department of Anatomy, Iwate Medical University, Iwate, Japan
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Small GTPases and their guanine-nucleotide exchange factors and GTPase-activating proteins in neutrophil recruitment. Curr Opin Hematol 2016; 23:44-54. [PMID: 26619317 DOI: 10.1097/moh.0000000000000199] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE OF REVIEW The review describes the roles of Rho- and Rap-guanosine triphosphatases (GTPases) and of their activators, guanine-nucleotide exchange factors (GEFs), and inhibitors, GTPase activating proteins (GAPs), in neutrophil recruitment from the blood stream into inflamed tissues, with a focus on recently identified roles in neutrophils, endothelial cells, and platelets. RECENT FINDINGS Recent studies have identified important roles of Rho- and Rap-GTPases, and of their GEFs and GAPs, in the neutrophil recruitment cascade. These proteins control the upregulation and/or activation of adhesion molecules on the surface of neutrophils, endothelial cells, and platelets, and they alter cell/cell adhesion in the vascular endothelium. This enables the capture of neutrophils from the blood stream, their migration along and through the vessel wall, and their passage into the inflamed tissue. In particular, it has recently become clear that P-Rex and Vav family Rac-GEFs in platelets are crucial for neutrophil recruitment. SUMMARY These recent findings have contributed greatly to our understanding of the signalling pathways that control neutrophil recruitment to sites of inflammation and have opened up new avenues of research in this field.
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Lai YT, Lo CM. Assessing in vitro cytotoxicity of cell micromotion by Hilbert-Huang transform. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2014:3200-3. [PMID: 25570671 DOI: 10.1109/embc.2014.6944303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Electric cell-substrate impedance sensing (ECIS) is a powerful instrument for quantifying cell behavior in tissue culture. As cells attach and spread on the sensing electrode, they restrict the current flow and hence cause the increase of electrical impedance. Furthermore, cell motion may reveal itself as electrical fluctuations, which are always associated with living cells and continue even when the cells become fully confluent. The impedance fluctuation is attributed to incessant changes in the size of the cell-substrate space as cells persistently rearrange their cell-substrate adhesion sites. The magnitude of this sort of vertical motion detected by ECIS is of the order of nanometers and referred to as micromotion. In this study, Hilbert-Huang Transform was used as a micromotion analysis tool to distinguish the in vitro cytotoxicity of human umbilical vein endothelial cells (HUVECs) exposed to low levels of cytochalasin B. Hilbert-Huang Transform consists of two procedures: the empirical mode decomposition (EMD) and the Hilbert Transform. The measured impedance fluctuations due to cell micromotion were decomposed into several intrinsic mode functions (IMFs) by EMD, and then these IMFs were transferred to instantaneous frequencies by Hilbert Transform. Both amplitude and phase of instantaneous frequencies were expressed as a time-frequency spectrum, called Hilbert spectrum, which displayed different distribution pattern in response to different cytochalasin B concentration. The total instantaneous energy (IE) of each IMF was also calculated to quantify the spectral difference. In addition to the observation of a dose-dependent relationship, the IE value of the first IMF at 0.1 μM decreased to about 48% of the control value and significantly distinguished the cytotoxic effect of 0.1 μM of cytochalasin B (P<0.05).
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Abstract
The establishment and maintenance of epithelial cell-cell junctions is crucially important to regulate adhesion, apico-basal polarity and motility of epithelial cells, and ultimately controls the architecture and physiology of epithelial organs. Junctions are supported, shaped and regulated by cytoskeletal filaments, whose dynamic organization and contractility are finely tuned by GTPases of the Rho family, primarily RhoA, Rac1 and Cdc42. Recent research has identified new molecular mechanisms underlying the cross-talk between these GTPases and epithelial junctions. Here we briefly summarize the current knowledge about the organization, molecular evolution and cytoskeletal anchoring of cell-cell junctions, and we comment on the most recent advances in the characterization of the interactions between Rho GTPases and junctional proteins, and their consequences with regards to junction assembly and regulation of cell behavior in vertebrate model systems. The concept of “zonular signalosome” is proposed, which highlights the close functional relationship between proteins of zonular junctions (zonulae occludentes and adhaerentes) and the control of cytoskeletal organization and signaling through Rho GTPases, transcription factors, and their effectors.
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Key Words
- AJ, adherens junction
- AMOT, angiomotin
- AMPK, Adenosine Monophosphate-Activated Protein Kinase
- APC, adenomatous poliposis coli
- CD2AP, CD2-associated protein
- CGN, cingulin
- CGNL1, paracingulin
- Cdc42
- Cdc42, cell division cycle 42
- DLC, deleted in liver cancer
- Dbl, diffuse B-cell lymphoma
- EPLIN, epithelial protein lost in neoplasm
- ERK, extracellular regulated kinase
- FERM, four.point.one, ezrin, radixin, moesin
- FGD5, FYVE, RhoGEF and PH domain containing 5
- GAP, GTPase activating protein
- GEF, guanine nucleotide exchange factor
- GST, glutathione -S- transferase; JAM = junctional adhesion molecule
- MCF-7, Michigan Cancer Foundation - 7
- MDCK, Madin Darby Canine Kidney
- MKLP1, mitotic kinesin-like protein-1
- MRCK, myotonic dystrophy-related Cdc42-binding kinase
- MgcRacGAP, male germ cell racGAP
- PA, puncta adhaerentia
- PAK, p21-activated kinase; PATJ, Pals1 associated tight junction protein
- PCNA, proliferating cell nuclear antigen
- PDZ, Post synaptic density protein (PSD95), Drosophila, disc large tumour suppressor (DlgA), and zonula occludens-1
- PLEKHA7, pleckstrin homology domain containing, family A member 7
- RICH-1, RhoGAP interacting with CIP4 homologues
- ROCK, Rho-associated protein kinase
- Rac
- Rho
- SH3BP1, (SH3 domain 490 binding protein-1)
- TJ, tight junction
- Tbx-3, T-box-3
- Tiam, Tumor invasion and metastasis
- WASP, Wiskott-Aldrich Syndrome Protein
- WAVE, WASP family Verprolin-homologous protein
- ZA, zonula adhaerens
- ZO, zonula occludens
- ZONAB, (ZO-1)–associated nucleic acid binding protein.
- cytoseleton
- epithelium
- junctions
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Affiliation(s)
- Sandra Citi
- a Department of Cell Biology ; University of Geneva ; Geneva , Switzerland
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19
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Abstract
Signaling via the Rho GTPases provides crucial regulation of numerous cell polarization events, including apicobasal (AB) polarity, polarized cell migration, polarized cell division and neuronal polarity. Here we review the relationships between the Rho family GTPases and epithelial AB polarization events, focusing on the 3 best-characterized members: Rho, Rac and Cdc42. We discuss a multitude of processes that are important for AB polarization, including lumen formation, apical membrane specification, cell-cell junction assembly and maintenance, as well as tissue polarity. Our discussions aim to highlight the immensely complex regulatory mechanisms that encompass Rho GTPase signaling during AB polarization. More specifically, in this review we discuss several emerging common themes, that include: 1) the need for Rho GTPase activities to be carefully balanced in both a spatial and temporal manner through a multitude of mechanisms; 2) the existence of signaling feedback loops and crosstalk to create robust cellular responses; and 3) the frequent multifunctionality that exists among AB polarity regulators. Regarding this latter theme, we provide further discussion of the potential plasticity of the cell polarity machinery and as a result the possible implications for human disease.
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Key Words
- AB, Apicobasal
- AJ, Adherens junction
- Amot, Angiomotin
- Arp2/3, Actin-related protein-2/3
- Baz, Bazooka
- C. elegans, Caenorhabditis elegans
- CA, Constitutively-active
- CD2AP, CD2-associated protein
- Caco2, Human colon carcinoma
- Cdc42
- Cora, Coracle
- Crb, Crumbs
- DN, Dominant-negative
- Dia1, Diaphanous-related formin 1
- Dlg, Discs large
- Drosophila, Drosophila melanogaster
- Dys-β, Dystrobrevin-β
- ECM, Extracellular matrix
- Ect2, Epithelial cell transforming sequence 2 oncogene
- Eya1, Eyes absent 1
- F-actin, Filamentous actin
- FRET, Fluorescence resonance energy transfer
- GAP, GTPase-activating protein
- GDI, Guanine nucleotide dissociation inhibitor
- GEF, Guanine nucleotide exchange factor
- GTPases
- JACOP, Junction-associated coiled-coiled protein
- JAM, Junctional adhesion molecule
- LKB1, Liver kinase B1
- Lgl, Lethal giant larvae
- MDCK, Madin-Darby canine kidney
- MTOC, Microtubule-organizing center
- NrxIV, Neurexin IV
- Pals1, Protein associated with Lin-7 1
- Par, Partitioning-defective
- Patj, Pals1-associated TJ protein
- ROCK, Rho-associated kinase
- Rac
- Rho
- Rich1, RhoGAP interacting with CIP4 homologues
- S. cerevisiae, Saccharomyces cerevisiae
- S. pombe, Schizosaccharomyces pombe
- SH3BP1, SH3-domain binding protein 1
- Scrib, Scribble
- Std, Stardust
- TEM4, Tumor endothelial marker 4
- TJ, Tight junction
- Tiam1, T-cell lymphoma invasion and metastasis-inducing protein 1
- WASp, Wiskott-aldrich syndrome protein
- Yrt, Yurt
- ZA, zonula adherens
- ZO, Zonula occludens
- aPKC, Atypical Protein Kinase C
- apicobasal
- epithelia
- junction
- par
- polarity
- α-cat, Alpha-catenin
- β-cat, Beta-Catenin
- β2-syn, Beta-2-syntrophin
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Affiliation(s)
- Natalie Ann Mack
- a School of Life Sciences; Queens Medical Center ; University of Nottingham ; Nottingham , UK
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Timmerman I, Heemskerk N, Kroon J, Schaefer A, van Rijssel J, Hoogenboezem M, van Unen J, Goedhart J, Gadella TWJ, Yin T, Wu Y, Huveneers S, van Buul JD. A local VE-cadherin and Trio-based signaling complex stabilizes endothelial junctions through Rac1. J Cell Sci 2015; 128:3041-54. [PMID: 26116572 DOI: 10.1242/jcs.168674] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 06/22/2015] [Indexed: 01/08/2023] Open
Abstract
Endothelial cell-cell junctions maintain a restrictive barrier that is tightly regulated to allow dynamic responses to permeability-inducing angiogenic factors, as well as to inflammatory agents and adherent leukocytes. The ability of these stimuli to transiently remodel adherens junctions depends on Rho-GTPase-controlled cytoskeletal rearrangements. How the activity of Rho-GTPases is spatio-temporally controlled at endothelial adherens junctions by guanine-nucleotide exchange factors (GEFs) is incompletely understood. Here, we identify a crucial role for the Rho-GEF Trio in stabilizing junctions based around vascular endothelial (VE)-cadherin (also known as CDH5). Trio interacts with VE-cadherin and locally activates Rac1 at adherens junctions during the formation of nascent contacts, as assessed using a novel FRET-based Rac1 biosensor and biochemical assays. The Rac-GEF domain of Trio is responsible for the remodeling of junctional actin from radial into cortical actin bundles, a crucial step for junction stabilization. This promotes the formation of linear adherens junctions and increases endothelial monolayer resistance. Collectively, our data show the importance of spatio-temporal regulation of the actin cytoskeleton through Trio and Rac1 at VE-cadherin-based cell-cell junctions in the maintenance of the endothelial barrier.
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Affiliation(s)
- Ilse Timmerman
- Department of Molecular Cell Biology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, Amsterdam 1066 CX, The Netherlands
| | - Niels Heemskerk
- Department of Molecular Cell Biology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, Amsterdam 1066 CX, The Netherlands
| | - Jeffrey Kroon
- Department of Molecular Cell Biology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, Amsterdam 1066 CX, The Netherlands
| | - Antje Schaefer
- Department of Molecular Cell Biology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, Amsterdam 1066 CX, The Netherlands
| | - Jos van Rijssel
- Department of Molecular Cell Biology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, Amsterdam 1066 CX, The Netherlands
| | - Mark Hoogenboezem
- Department of Molecular Cell Biology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, Amsterdam 1066 CX, The Netherlands
| | - Jakobus van Unen
- Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, Amsterdam 1098 XH, The Netherlands
| | - Joachim Goedhart
- Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, Amsterdam 1098 XH, The Netherlands
| | - Theodorus W J Gadella
- Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, Amsterdam 1098 XH, The Netherlands
| | - Taofei Yin
- Center for Cell Analysis and Modelling, University of Connecticut Health Center, Farmington, CT 06032, USA
| | - Yi Wu
- Center for Cell Analysis and Modelling, University of Connecticut Health Center, Farmington, CT 06032, USA
| | - Stephan Huveneers
- Department of Molecular Cell Biology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, Amsterdam 1066 CX, The Netherlands
| | - Jaap D van Buul
- Department of Molecular Cell Biology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, Amsterdam 1066 CX, The Netherlands
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21
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Nakahara S, Tsutsumi K, Zuinen T, Ohta Y. FilGAP, a Rho–ROCK-regulated GAP for Rac, controls adherens junctions in MDCK cells. J Cell Sci 2015; 128:2047-56. [DOI: 10.1242/jcs.160192] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 04/14/2015] [Indexed: 01/05/2023] Open
Abstract
ABSTRACT
Rho family small GTPases are essential for the formation of adherens junctions in epithelial cells. Here, we found that FilGAP (also known as ARHGAP24), a Rac-specific Rho GTPase-activating protein, promoted the formation of adherens junctions in Madin–Darby canine kidney (MDCK) cells. Knockdown of FilGAP by siRNA stimulated the disassembly and migration of MDCK cells induced by hepatocyte growth factor (HGF). By contrast, forced expression of FilGAP induced accumulation of E-cadherin at adherens junctions. Endogenous FilGAP colocalized with E-cadherin at adherens junctions, and depletion of FilGAP reduced the amount of E-cadherin expressed at the surface. The Rac GAP domain of FilGAP was necessary for the suppression of cell scattering induced by HGF. In agreement with this, siRNA-mediated knockdown of both Rac1 and FilGAP suppressed cell scattering induced by HGF. Forced expression of Rho kinase (ROCK, of which there are two isoforms ROCK1 and ROCK2) induced the accumulation of E-cadherin at the adherens junction, and depletion of FilGAP prevented the accumulation of E-cadherin. Moreover, wild-type FilGAP but not a non-phosphorylatable FilGAP mutant rescued the accumulation of E-cadherin at adherens junctions. These results suggest that FilGAP might regulate cell–cell adhesion through inactivation of Rac downstream of Rho–ROCK-signaling in MDCK cells.
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Affiliation(s)
- Shinichiro Nakahara
- Division of Cell Biology, Department of Biosciences, School of Science, Kitasato University, Kanagawa 252-0373, Japan
| | - Koji Tsutsumi
- Division of Cell Biology, Department of Biosciences, School of Science, Kitasato University, Kanagawa 252-0373, Japan
| | - Takuya Zuinen
- Division of Cell Biology, Department of Biosciences, School of Science, Kitasato University, Kanagawa 252-0373, Japan
| | - Yasutaka Ohta
- Division of Cell Biology, Department of Biosciences, School of Science, Kitasato University, Kanagawa 252-0373, Japan
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22
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van Buul JD, Geerts D, Huveneers S. Rho GAPs and GEFs: controling switches in endothelial cell adhesion. Cell Adh Migr 2015; 8:108-24. [PMID: 24622613 PMCID: PMC4049857 DOI: 10.4161/cam.27599] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Within blood vessels, endothelial cell–cell and cell–matrix adhesions are crucial to preserve barrier function, and these adhesions are tightly controlled during vascular development, angiogenesis, and transendothelial migration of inflammatory cells. Endothelial cellular signaling that occurs via the family of Rho GTPases coordinates these cell adhesion structures through cytoskeletal remodelling. In turn, Rho GTPases are regulated by GTPase-activating proteins (GAPs) and guanine nucleotide exchange factors (GEFs). To understand how endothelial cells initiate changes in the activity of Rho GTPases, and thereby regulate cell adhesion, we will discuss the role of Rho GAPs and GEFs in vascular biology. Many potentially important Rho regulators have not been studied in detail in endothelial cells. We therefore will first overview which GAPs and GEFs are highly expressed in endothelium, based on comparative gene expression analysis of human endothelial cells compared with other tissue cell types. Subsequently, we discuss the relevance of Rho GAPs and GEFs for endothelial cell adhesion in vascular homeostasis and disease.
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Affiliation(s)
- Jaap D van Buul
- Department of Molecular Cell Biology; Sanquin Research and Swammerdam Institute for Life Sciences; University of Amsterdam; The Netherlands
| | - Dirk Geerts
- Department of Pediatric Oncology/Hematology; Erasmus University Medical Center; Rotterdam, The Netherlands
| | - Stephan Huveneers
- Department of Molecular Cell Biology; Sanquin Research and Swammerdam Institute for Life Sciences; University of Amsterdam; The Netherlands
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23
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Durgan J, Tao G, Walters MS, Florey O, Schmidt A, Arbelaez V, Rosen N, Crystal RG, Hall A. SOS1 and Ras regulate epithelial tight junction formation in the human airway through EMP1. EMBO Rep 2015; 16:87-96. [PMID: 25394671 PMCID: PMC4304732 DOI: 10.15252/embr.201439218] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 10/23/2014] [Accepted: 10/24/2014] [Indexed: 11/09/2022] Open
Abstract
The human airway is lined with respiratory epithelial cells, which create a critical barrier through the formation of apical tight junctions. To investigate the molecular mechanisms underlying this process, an RNAi screen for guanine nucleotide exchange factors (GEFs) was performed in human bronchial epithelial cells (16HBE). We report that SOS1, acting through the Ras/MEK/ERK pathway, is essential for tight junction formation. Global microarray analysis identifies epithelial membrane protein 1 (EMP1), an integral tetraspan membrane protein, as a major transcriptional target. EMP1 is indispensable for tight junction formation and function in 16HBE cells and in a human airway basal progenitor-like cell line (BCi-NS1.1). Furthermore, EMP1 is significantly downregulated in human lung cancers. Together, these data identify important roles for SOS1/Ras and EMP1 in tight junction assembly during airway morphogenesis.
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Affiliation(s)
- Joanne Durgan
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Guangbo Tao
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Matthew S Walters
- Department of Genetic Medicine, Weill Cornell Medical College, New York, NY, USA
| | - Oliver Florey
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Anja Schmidt
- MRC Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Vanessa Arbelaez
- Department of Genetic Medicine, Weill Cornell Medical College, New York, NY, USA
| | - Neal Rosen
- Molecular Pharmacology & Chemistry Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Ronald G Crystal
- Department of Genetic Medicine, Weill Cornell Medical College, New York, NY, USA
| | - Alan Hall
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
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24
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Zhao X, Rotenberg SA. Phosphorylation of Cdc42 effector protein-4 (CEP4) by protein kinase C promotes motility of human breast cells. J Biol Chem 2014; 289:25844-54. [PMID: 25086031 DOI: 10.1074/jbc.m114.577783] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Cdc42 effector protein-4 (CEP4) was recently identified by our laboratory to be a substrate of multiple PKC isoforms in non-transformed MCF-10A human breast cells. The significance of phosphorylated CEP4 to PKC-stimulated motility of MCF-10A cells was evaluated. Single site mutants at Ser residues embedded in potential PKC consensus sites (Ser(18), Ser(77), Ser(80), and Ser(86)) were individually replaced with Asp residues to simulate phosphorylation. Following expression in weakly motile MCF-10A cells, the S18D and S80D mutants each promoted increased motility, and the double mutant (S18D/S80D) produced a stronger effect. MS/MS analysis verified that Ser(18) and Ser(80) were directly phosphorylated by PKCα in vitro. Phosphorylation of CEP4 severely diminished its affinity for Cdc42 while promoting Rac activation and formation of filopodia (microspikes). In contrast, the phosphorylation-resistant double mutant S18A/S80A-CEP4 blocked CEP4 phosphorylation and inhibited motility of MCF-10A cells that had been stimulated with PKC activator diacylglycerol lactone. In view of the dissociation of phospho-CEP4 from Cdc42, intracellular binding partners were explored by expressing each CEP4 double mutant from a tandem affinity purification vector followed by affinity chromatography, SDS-PAGE, and identification of protein bands evident only with S18D/S80D-CEP4. One binding partner was identified as tumor endothelial marker-4 (TEM4; ARHGEF17), a guanine nucleotide exchange factor that is involved in migration. In motile cells expressing S18D/S80D-CEP4, knockdown of TEM4 inhibited both Rac activation and motility. These findings support a model in which PKC-mediated phosphorylation of CEP4 at Ser(18) and Ser(80) causes its dissociation from Cdc42, thereby increasing its affinity for TEM4 and producing Rac activation, filopodium formation, and cell motility.
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Affiliation(s)
- Xin Zhao
- From the Department of Chemistry and Biochemistry, Queens College, Flushing, New York 11367 and The Graduate Center, The City University of New York, New York, New York 10016
| | - Susan A Rotenberg
- From the Department of Chemistry and Biochemistry, Queens College, Flushing, New York 11367 and
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Ngok SP, Lin WH, Anastasiadis PZ. Establishment of epithelial polarity--GEF who's minding the GAP? J Cell Sci 2014; 127:3205-15. [PMID: 24994932 DOI: 10.1242/jcs.153197] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Cell polarization is a fundamental process that underlies epithelial morphogenesis, cell motility, cell division and organogenesis. Loss of polarity predisposes tissues to developmental disorders and contributes to cancer progression. The formation and establishment of epithelial cell polarity is mediated by the cooperation of polarity protein complexes, namely the Crumbs, partitioning defective (Par) and Scribble complexes, with Rho family GTPases, including RhoA, Rac1 and Cdc42. The activation of different GTPases triggers distinct downstream signaling pathways to modulate protein-protein interactions and cytoskeletal remodeling. The spatio-temporal activation and inactivation of these small GTPases is tightly controlled by a complex interconnected network of different regulatory proteins, including guanine-nucleotide-exchange factors (GEFs), GTPase-activating proteins (GAPs), and guanine-nucleotide-dissociation inhibitors (GDIs). In this Commentary, we focus on current understanding on how polarity complexes interact with GEFs and GAPs to control the precise location and activation of Rho GTPases (Crumbs for RhoA, Par for Rac1, and Scribble for Cdc42) to promote apical-basal polarization in mammalian epithelial cells. The mutual exclusion of GTPase activities, especially that of RhoA and Rac1, which is well established, provides a mechanism through which polarity complexes that act through distinct Rho GTPases function as cellular rheostats to fine-tune specific downstream pathways to differentiate and preserve the apical and basolateral domains. This article is part of a Minifocus on Establishing polarity.
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Affiliation(s)
- Siu P Ngok
- Department of Cancer Biology, Mayo Clinic Comprehensive Cancer Center, Griffin Cancer Research Building, Room 307, 4500 San Pablo Road, Jacksonville, FL 32224, USA
| | - Wan-Hsin Lin
- Department of Cancer Biology, Mayo Clinic Comprehensive Cancer Center, Griffin Cancer Research Building, Room 307, 4500 San Pablo Road, Jacksonville, FL 32224, USA
| | - Panos Z Anastasiadis
- Department of Cancer Biology, Mayo Clinic Comprehensive Cancer Center, Griffin Cancer Research Building, Room 307, 4500 San Pablo Road, Jacksonville, FL 32224, USA
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Takeichi M. Dynamic contacts: rearranging adherens junctions to drive epithelial remodelling. Nat Rev Mol Cell Biol 2014; 15:397-410. [PMID: 24824068 DOI: 10.1038/nrm3802] [Citation(s) in RCA: 403] [Impact Index Per Article: 40.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Epithelial cells display dynamic behaviours, such as rearrangement, movement and shape changes, particularly during embryonic development and in equivalent processes in adults. Accumulating evidence suggests that the remodelling of cell junctions, especially adherens junctions (AJs), has major roles in controlling these behaviours. AJs comprise cadherin adhesion receptors and cytoplasmic proteins that associate with them, including catenins and actin filaments, and exhibit various forms, such as linear or punctate. Remodelling of AJs induces epithelial reshaping in various ways, including by planar-polarized apical constriction that is driven by the contraction of AJ-associated actomyosin and that occurs during neural plate bending and germband extension. RHO GTPases and their effectors regulate actin polymerization and actomyosin contraction at AJs during the epithelial reshaping processes.
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Affiliation(s)
- Masatoshi Takeichi
- RIKEN Center for Developmental Biology, 2-2-3 Chuo-ku, Kobe 650-0047, Japan
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Amado-Azevedo J, Valent ET, Van Nieuw Amerongen GP. Regulation of the endothelial barrier function: a filum granum of cellular forces, Rho-GTPase signaling and microenvironment. Cell Tissue Res 2014; 355:557-76. [PMID: 24633925 DOI: 10.1007/s00441-014-1828-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 01/24/2014] [Indexed: 12/20/2022]
Abstract
Although the endothelium is an extremely thin single-cell layer, it performs exceedingly well in preventing blood fluids from leaking into the surrounding tissues. However, specific pathological conditions can affect this cell layer, compromising the integrity of the barrier. Vascular leakage is a hallmark of many cardiovascular diseases and despite its medical importance, no specialized therapies are available to prevent it or reduce it. Small guanosine triphosphatases (GTPases) of the Rho family are known to be key regulators of various aspects of cell behavior and studies have shown that they can exert both positive and negative effects on endothelial barrier integrity. Moreover, extracellular matrix stiffness has now been implicated in the regulation of Rho-GTPase signaling, which has a direct impact on the integrity of endothelial junctions. However, knowledge about both the precise mechanism of this regulation and the individual contribution of the specific regulatory proteins remains fragmentary. In this review, we discuss recent findings concerning the balanced activities of Rho-GTPases and, in particular, aspects of the regulation of the endothelial barrier. We highlight the role of Rho-GTPases in the intimate relationships between biomechanical forces, microenvironmental influences and endothelial intercellular junctions, which are all interwoven in a beautiful filigree-like fashion.
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Affiliation(s)
- Joana Amado-Azevedo
- Laboratory for Physiology, Institute for Cardiovascular Research, VU University Medical Center, Van den Boechorststraat 7, 1081BT, Amsterdam, The Netherlands
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Schlegel N, Waschke J. cAMP with other signaling cues converges on Rac1 to stabilize the endothelial barrier- a signaling pathway compromised in inflammation. Cell Tissue Res 2013; 355:587-96. [PMID: 24322391 DOI: 10.1007/s00441-013-1755-y] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Accepted: 10/31/2013] [Indexed: 12/20/2022]
Abstract
cAMP is one of the most potent signaling molecules to stabilize the endothelial barrier, both under resting conditions as well as under challenge of barrier-destabilizing mediators. The two main signaling axes downstream of cAMP are activation of protein kinase A (PKA) as well as engagement of exchange protein directly activated by cAMP (Epac) and its effector GTPase Rap1. Interestingly, both pathways activate GTP exchange factors for Rac1, such as Tiam1 and Vav2 and stabilize the endothelial barrier via Rac1-mediated enforcement of adherens junctions and strengthening of the cortical actin cytoskeleton. On the level of Rac1, cAMP signaling converges with other barrier-enhancing signaling cues induced by sphingosine-1-phosphate (S1P) and angiopoietin-1 (Ang1) rendering Rac1 as an important signaling hub. Moreover, activation of Rap1 and inhibition of RhoA also contribute to barrier stabilization, emphasizing that regulation of small GTPases is a central mechanism in this context. The relevance of cAMP/Rac1-mediated barrier protection under pathophysiologic conditions can be concluded from data showing that inflammatory mediators causing multi-organ failure in systemic inflammation or sepsis interfere with this signaling axis on the level of cAMP or Rac1. This is in line with the well-known efficacy of cAMP to abrogate the barrier breakdown in response to most barrier-compromising stimuli. New is the notion that the tight endothelial barrier under resting conditions is maintained by (1) continuous cAMP formation induced by hormones such as epinephrine or (2) by activation of Rac1 downstream of S1P that is secreted by erythrocytes and activated platelets.
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Affiliation(s)
- Nicolas Schlegel
- Department of General-, Visceral, Vascular and Pediatric surgery, University Hospital Wuerzburg, Oberduerrbacherstrasse 6, 97080, Wuerzburg, Germany
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Ngok SP, Anastasiadis PZ. Rho GEFs in endothelial junctions: Effector selectivity and signaling integration determine junctional response. Tissue Barriers 2013; 1:e27132. [PMID: 24790803 DOI: 10.4161/tisb.27132] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 11/07/2013] [Accepted: 11/08/2013] [Indexed: 12/31/2022] Open
Abstract
Rho GTPases are cytoskeleton-regulating proteins that mediate the formation of intercellular junctions. Their localized activation by Rho GEFs (guanine-nucleotide exchange factors) and the selective activation of downstream effectors have emerged as areas of active research in the cell adhesion field. We reported recently that the Rho-specific GEFs Syx (Synectin-binding RhoA exchange factor) and TEM4 (Tumor Endothelial Marker 4) are both essential for endothelial junction maturation and barrier function. Syx is recruited to cell contacts via its C-terminal PDZ binding motif and it's interaction with Mupp1 and the Crumbs polarity complex, while the junctional localization of TEM4 requires it's N-terminal domain and interaction with the cadherin-catenin complex. Our findings support multiple roles for RhoA in junction formation and maintenance. They also suggest that selective coupling of RhoA activation to Dia1 and/or ROCK signaling is critical for determining endothelial junction integrity.
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Affiliation(s)
- Siu P Ngok
- Department of Cancer Biology; Mayo Clinic Comprehensive Cancer Center; Jacksonville, FL, USA
| | - Panos Z Anastasiadis
- Department of Cancer Biology; Mayo Clinic Comprehensive Cancer Center; Jacksonville, FL, USA
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