1
|
Yang YA, Nguyen E, Sankara Narayana GHN, Heuzé M, Fu C, Yu H, Mège RM, Ladoux B, Sheetz MP. Local contractions regulate E-cadherin rigidity sensing. SCIENCE ADVANCES 2022; 8:eabk0387. [PMID: 35089785 PMCID: PMC8797795 DOI: 10.1126/sciadv.abk0387] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
E-cadherin is a major cell-cell adhesion molecule involved in mechanotransduction at cell-cell contacts in tissues. Because epithelial cells respond to rigidity and tension in tissue through E-cadherin, there must be active processes that test and respond to the mechanical properties of these adhesive contacts. Using submicrometer, E-cadherin-coated polydimethylsiloxane pillars, we find that cells generate local contractions between E-cadherin adhesions and pull to a constant distance for a constant duration, irrespective of pillar rigidity. These cadherin contractions require nonmuscle myosin IIB, tropomyosin 2.1, α-catenin, and binding of vinculin to α-catenin. Cells spread to different areas on soft and rigid surfaces with contractions, but spread equally on soft and rigid without. We further observe that cadherin contractions enable cells to test myosin IIA-mediated tension of neighboring cells and sort out myosin IIA-depleted cells. Thus, we suggest that epithelial cells test and respond to the mechanical characteristics of neighboring cells through cadherin contractions.
Collapse
Affiliation(s)
- Yi-An Yang
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
| | - Emmanuelle Nguyen
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
| | | | - Melina Heuzé
- Université de Paris, CNRS, Institut Jacques Monod, F-75013 Paris, France
| | - Chaoyu Fu
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
| | - Hanry Yu
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
- Department of Physiology, Institute for Digital Medicine (WisDM), Yong Loo Lin School of Medicine, Singapore 117593, Singapore
- Institute of Bioengineering and Bioimaging, A*STAR, Singapore 138669, Singapore
- CAMP, Singapore-MIT Alliance for Research and Technology, Singapore 138602, Singapore
| | - René-Marc Mège
- Université de Paris, CNRS, Institut Jacques Monod, F-75013 Paris, France
| | - Benoit Ladoux
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
- Université de Paris, CNRS, Institut Jacques Monod, F-75013 Paris, France
- Corresponding author. (M.P.S.); (B.L.)
| | - Michael P. Sheetz
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
- Corresponding author. (M.P.S.); (B.L.)
| |
Collapse
|
2
|
Polanco J, Reyes-Vigil F, Weisberg SD, Dhimitruka I, Brusés JL. Differential Spatiotemporal Expression of Type I and Type II Cadherins Associated With the Segmentation of the Central Nervous System and Formation of Brain Nuclei in the Developing Mouse. Front Mol Neurosci 2021; 14:633719. [PMID: 33833667 PMCID: PMC8021962 DOI: 10.3389/fnmol.2021.633719] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 02/10/2021] [Indexed: 11/20/2022] Open
Abstract
Type I and type II classical cadherins comprise a family of cell adhesion molecules that regulate cell sorting and tissue separation by forming specific homo and heterophilic bonds. Factors that affect cadherin-mediated cell-cell adhesion include cadherin binding affinity and expression level. This study examines the expression pattern of type I cadherins (Cdh1, Cdh2, Cdh3, and Cdh4), type II cadherins (Cdh6, Cdh7, Cdh8, Cdh9, Cdh10, Cdh11, Cdh12, Cdh18, Cdh20, and Cdh24), and the atypical cadherin 13 (Cdh13) during distinct morphogenetic events in the developing mouse central nervous system from embryonic day 11.5 to postnatal day 56. Cadherin mRNA expression levels obtained from in situ hybridization experiments carried out at the Allen Institute for Brain Science (https://alleninstitute.org/) were retrieved from the Allen Developing Mouse Brain Atlas. Cdh2 is the most abundantly expressed type I cadherin throughout development, while Cdh1, Cdh3, and Cdh4 are expressed at low levels. Type II cadherins show a dynamic pattern of expression that varies between neuroanatomical structures and developmental ages. Atypical Cdh13 expression pattern correlates with Cdh2 in abundancy and localization. Analyses of cadherin-mediated relative adhesion estimated from their expression level and binding affinity show substantial differences in adhesive properties between regions of the neural tube associated with the segmentation along the anterior–posterior axis. Differences in relative adhesion were also observed between brain nuclei in the developing subpallium (basal ganglia), suggesting that differential cell adhesion contributes to the segregation of neuronal pools. In the adult cerebral cortex, type II cadherins Cdh6, Cdh8, Cdh10, and Cdh12 are abundant in intermediate layers, while Cdh11 shows a gradated expression from the deeper layer 6 to the superficial layer 1, and Cdh9, Cdh18, and Cdh24 are more abundant in the deeper layers. Person’s correlation analyses of cadherins mRNA expression patterns between areas and layers of the cerebral cortex and the nuclei of the subpallium show significant correlations between certain cortical areas and the basal ganglia. The study shows that differential cadherin expression and cadherin-mediated adhesion are associated with a wide range of morphogenetic events in the developing central nervous system including the organization of neurons into layers, the segregation of neurons into nuclei, and the formation of neuronal circuits.
Collapse
Affiliation(s)
- Julie Polanco
- Department of Natural Sciences, Mercy College, Dobbs Ferry, NY, United States
| | - Fredy Reyes-Vigil
- Department of Natural Sciences, Mercy College, Dobbs Ferry, NY, United States
| | - Sarah D Weisberg
- Department of Natural Sciences, Mercy College, Dobbs Ferry, NY, United States
| | - Ilirian Dhimitruka
- Department of Natural Sciences, Mercy College, Dobbs Ferry, NY, United States
| | - Juan L Brusés
- Department of Natural Sciences, Mercy College, Dobbs Ferry, NY, United States
| |
Collapse
|
3
|
Fedele L, Brand T. The Intrinsic Cardiac Nervous System and Its Role in Cardiac Pacemaking and Conduction. J Cardiovasc Dev Dis 2020; 7:jcdd7040054. [PMID: 33255284 PMCID: PMC7712215 DOI: 10.3390/jcdd7040054] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 11/19/2020] [Accepted: 11/20/2020] [Indexed: 12/11/2022] Open
Abstract
The cardiac autonomic nervous system (CANS) plays a key role for the regulation of cardiac activity with its dysregulation being involved in various heart diseases, such as cardiac arrhythmias. The CANS comprises the extrinsic and intrinsic innervation of the heart. The intrinsic cardiac nervous system (ICNS) includes the network of the intracardiac ganglia and interconnecting neurons. The cardiac ganglia contribute to the tight modulation of cardiac electrophysiology, working as a local hub integrating the inputs of the extrinsic innervation and the ICNS. A better understanding of the role of the ICNS for the modulation of the cardiac conduction system will be crucial for targeted therapies of various arrhythmias. We describe the embryonic development, anatomy, and physiology of the ICNS. By correlating the topography of the intracardiac neurons with what is known regarding their biophysical and neurochemical properties, we outline their physiological role in the control of pacemaker activity of the sinoatrial and atrioventricular nodes. We conclude by highlighting cardiac disorders with a putative involvement of the ICNS and outline open questions that need to be addressed in order to better understand the physiology and pathophysiology of the ICNS.
Collapse
Affiliation(s)
- Laura Fedele
- Correspondence: (L.F.); (T.B.); Tel.: +44-(0)-207-594-6531 (L.F.); +44-(0)-207-594-8744 (T.B.)
| | - Thomas Brand
- Correspondence: (L.F.); (T.B.); Tel.: +44-(0)-207-594-6531 (L.F.); +44-(0)-207-594-8744 (T.B.)
| |
Collapse
|
4
|
Tang W, Fang F, Liu K, Huang Z, Li H, Yin Y, Wang J, Wang G, Wei L, Ou Y, Wang Y. Aligned Biofunctional Electrospun PLGA-LysoGM1 Scaffold for Traumatic Brain Injury Repair. ACS Biomater Sci Eng 2020; 6:2209-2218. [PMID: 33455302 DOI: 10.1021/acsbiomaterials.9b01636] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Due to poor regenerative capabilities of the brain, a treatment for traumatic brain injury (TBI) presents a serious challenge to modern medicine. Biofunctional scaffolds that can support neuronal growth, guide neurite elongation, and re-establish impaired brain tissues are urgently needed. To this end, we developed an aligned biofunctional scaffold (aPLGA-LysoGM1), in which poly (lactic-co-glycolic acid) (PLGA) was functionalized with sphingolipid ceramide N-deacylase (SCDase)-hydrolyzed monosialotetrahexosylganglioside (LysoGM1) and electrospinning was used to form an aligned fibrous network. As a ganglioside of neuronal membranes, the functionalized LysoGM1 endows the scaffold with unique biological properties favoring the growth of neuron and regeneration of injured brain tissues. Moreover, we found that the aligned PLGA-LysoGM1 fibers acted as a topographical cue to guide neurite extension, which is critical for organizing the formation of synaptic networks (neural networks). Systematic in vitro studies demonstrated that the aligned biofunctional scaffold promotes neuronal viability, neurite outgrowth, and synapse formation and also protects neurons from pressure-related injury. Additionally, in a rat TBI model, we demonstrated that the implantation of aPLGA-LysoGM1 scaffold supported recovery from brain injury, as more endogenous neurons were found to migrate and infiltrate into the defect zone compared with alternative scaffold. These results suggest that the aligned biofunctional aPLGA-LysoGM1 scaffold represents a promising therapeutic strategy for brain tissue regeneration following TBI.
Collapse
Affiliation(s)
- Wei Tang
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Fei Fang
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, China
| | - Ke Liu
- Institute of Biomedicine and Biotechnology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Zhi Huang
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, China
| | - Hui Li
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Ying Yin
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, China
| | - Jun Wang
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, China
| | - Guocheng Wang
- Institute of Biomedicine and Biotechnology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Liyu Wei
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Yun Ou
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.,Hunan Provincial Key Laboratory of Health Maintenance for Mechanical Equipment, Hunan University of Science and Technology, Xiangtan 411201, China
| | - Yazhou Wang
- School of Medicine, Chongqing University, Chongqing 400044, China.,Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, China
| |
Collapse
|
5
|
Yamagata M, Duan X, Sanes JR. Cadherins Interact With Synaptic Organizers to Promote Synaptic Differentiation. Front Mol Neurosci 2018; 11:142. [PMID: 29760652 PMCID: PMC5936767 DOI: 10.3389/fnmol.2018.00142] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 04/09/2018] [Indexed: 01/17/2023] Open
Abstract
Classical cadherins, a set of ~20 related recognition and signaling molecules, have been implicated in many aspects of neural development, including the formation and remodeling of synapses. Mechanisms underlying some of these steps have been studied by expressing N-cadherin (cdh2), a Type 1 cadherin, in heterologous cells, but analysis is complicated because widely used lines express cdh2 endogenously. We used CRISPR-mediated gene editing to generate a Human embryonic kidney (HEK)293 variant lacking Cdh2, then compared the behavior of rodent cortical and hippocampal neurons co-cultured with parental, cdh2 mutant and cdh2-rescued 293 lines. The comparison demonstrated that Cdh2 promotes neurite branching and that it is required for three synaptic organizers, neurologin1 (NLGL1), leucine-rich repeat transmembrane protein 2 (LRRtm2), and Cell Adhesion Molecule 1 (Cadm1/SynCAM) to stimulate presynaptic differentiation, assayed by clustering of synaptic vesicles at sites of neurite-293 cell contact. Similarly, Cdh2 is required for a presynaptic organizing molecule, Neurexin1β, to promote postsynaptic differentiation in dendrites. We also show that another Type I cadherin, Cdh4, and a Type II cadherin, Cdh6, can substitute for Cdh2 in these assays. Finally, we provide evidence that the effects of cadherins require homophilic interactions between neurites and the heterologous cells. Together, these results indicate that classical cadherins act together with synaptic organizers to promote synaptic differentiation, perhaps in part by strengthening the intracellular adhesion required for the organizers to act efficiently. We propose that cadherins promote high affinity contacts between appropriate partners, which then enable synaptic differentiation.
Collapse
Affiliation(s)
- Masahito Yamagata
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, United States
| | - Xin Duan
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, United States
| | - Joshua R Sanes
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, United States
| |
Collapse
|
6
|
Yang C, Li X, Wang C, Fu S, Li H, Guo Z, Zhao S, Lin J. N-cadherin regulates beta-catenin signal and its misexpression perturbs commissural axon projection in the developing chicken spinal cord. J Mol Histol 2016; 47:541-554. [PMID: 27650519 DOI: 10.1007/s10735-016-9698-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 09/14/2016] [Indexed: 12/31/2022]
Abstract
N-cadherin is a calcium-sensitive cell adhesion molecule that plays an important role in the formation of the neural circuit and the development of the nervous system. In the present study, we investigated the function of N-cadherin in cell-cell connection in vitro with HEK293T cells, and in commissural axon projections in the developing chicken spinal cord using in ovo electroporation. Cell-cell connections increased with N-cadherin overexpression in HEK293T cells, while cell contacts disappeared after co-transfection with an N-cadherin-shRNA plasmid. The knockdown of N-cadherin caused the accumulation of β-catenin in the nucleus, supporting the notion that N-cadherin regulates β-catenin signaling in vitro. Furthermore, N-cadherin misexpression perturbed commissural axon projections in the spinal cord. The overexpression of N-cadherin reduced the number of axons that projected alongside the contralateral margin of the floor plate, and formed intermediate longitudinal commissural axons. In contrast, the knockdown of N-cadherin perturbed commissural axon projections significantly, affecting the projections alongside the contralateral margin of the floor plate, but did not affect intermediate longitudinal commissural axons. Taken together, these findings suggest that N-cadherin regulates commissural axon projections in the developing chicken spinal cord.
Collapse
Affiliation(s)
- Ciqing Yang
- College of Life Science and Technology, Xinxiang Medical University, Xinxiang, 453003, China.,Henan Key Laboratory of Medical Tissue Regeneration, Xinxiang, 453003, China
| | - Xiaoying Li
- College of Life Science and Technology, Xinxiang Medical University, Xinxiang, 453003, China
| | - Congrui Wang
- Henan Key Laboratory of Medical Tissue Regeneration, Xinxiang, 453003, China
| | - Sulei Fu
- College of Life Science and Technology, Xinxiang Medical University, Xinxiang, 453003, China
| | - Han Li
- College of Life Science and Technology, Xinxiang Medical University, Xinxiang, 453003, China.,Advanced Medical and Dental Institute, Universiti Sains Malaysia, 13200, Bertam, Penang, Malaysia
| | - Zhikun Guo
- Henan Key Laboratory of Medical Tissue Regeneration, Xinxiang, 453003, China
| | - Shanting Zhao
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, China
| | - Juntang Lin
- College of Life Science and Technology, Xinxiang Medical University, Xinxiang, 453003, China. .,Henan Key Laboratory of Medical Tissue Regeneration, Xinxiang, 453003, China. .,Institute of Anatomy I, Jena University Hospital, 07743, Jena, Germany.
| |
Collapse
|
7
|
Haque A, Adnan N, Motazedian A, Akter F, Hossain S, Kutsuzawa K, Nag K, Kobatake E, Akaike T. An Engineered N-Cadherin Substrate for Differentiation, Survival, and Selection of Pluripotent Stem Cell-Derived Neural Progenitors. PLoS One 2015; 10:e0135170. [PMID: 26244942 PMCID: PMC4526632 DOI: 10.1371/journal.pone.0135170] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 07/18/2015] [Indexed: 11/18/2022] Open
Abstract
For stem cell-based treatment of neurodegenerative diseases a better understanding of key developmental signaling pathways and robust techniques for producing neurons with highest homogeneity are required. In this study, we demonstrate a method using N-cadherin-based biomimetic substrate to promote the differentiation of mouse embryonic stem cell (ESC)- and induced pluripotent stem cell (iPSC)-derived neural progenitor cells (NPCs) without exogenous neuro-inductive signals. We showed that substrate-dependent activation of N-cadherin reduces Rho/ROCK activation and β-catenin expression, leading to the stimulation of neurite outgrowth and conversion into cells expressing neural/glial markers. Besides, plating dissociated cells on N-cadherin substrate can significantly increase the differentiation yield via suppression of dissociation-induced Rho/ROCK-mediated apoptosis. Because undifferentiated ESCs and iPSCs have low affinity to N-cadherin, plating dissociated cells on N-cadherin-coated substrate increase the homogeneity of differentiation by purging ESCs and iPSCs (~30%) from a mixture of undifferentiated cells with NPCs. Using this label-free cell selection approach we enriched differentiated NPCs plated as monolayer without ROCK inhibitor. Therefore, N-cadherin biomimetic substrate provide a powerful tool for basic study of cell—material interaction in a spatially defined and substrate-dependent manner. Collectively, our approach is efficient, robust and cost effective to produce large quantities of differentiated cells with highest homogeneity and applicable to use with other types of cells.
Collapse
Affiliation(s)
- Amranul Haque
- Department of Biomolecular Engineering, Tokyo Institute of Technology, Yokohama, Japan
| | - Nihad Adnan
- Department of Biomolecular Engineering, Tokyo Institute of Technology, Yokohama, Japan
| | - Ali Motazedian
- Department of Biomolecular Engineering, Tokyo Institute of Technology, Yokohama, Japan
| | - Farhima Akter
- Department of Biological Information, Tokyo Institute of Technology, Yokohama, Japan
| | - Sharif Hossain
- Department of Biomolecular Engineering, Tokyo Institute of Technology, Yokohama, Japan
| | - Koichi Kutsuzawa
- Department of Biomolecular Engineering, Tokyo Institute of Technology, Yokohama, Japan
| | - Kakon Nag
- Department of Biomolecular Engineering, Tokyo Institute of Technology, Yokohama, Japan
| | - Eiry Kobatake
- Department of Biological Information, Tokyo Institute of Technology, Yokohama, Japan
| | - Toshihiro Akaike
- Department of Biomolecular Engineering, Tokyo Institute of Technology, Yokohama, Japan
- * E-mail:
| |
Collapse
|
8
|
Friedman LG, Benson DL, Huntley GW. Cadherin-based transsynaptic networks in establishing and modifying neural connectivity. Curr Top Dev Biol 2015; 112:415-65. [PMID: 25733148 DOI: 10.1016/bs.ctdb.2014.11.025] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
It is tacitly understood that cell adhesion molecules (CAMs) are critically important for the development of cells, circuits, and synapses in the brain. What is less clear is what CAMs continue to contribute to brain structure and function after the early period of development. Here, we focus on the cadherin family of CAMs to first briefly recap their multidimensional roles in neural development and then to highlight emerging data showing that with maturity, cadherins become largely dispensible for maintaining neuronal and synaptic structure, instead displaying new and narrower roles at mature synapses where they critically regulate dynamic aspects of synaptic signaling, structural plasticity, and cognitive function. At mature synapses, cadherins are an integral component of multiprotein networks, modifying synaptic signaling, morphology, and plasticity through collaborative interactions with other CAM family members as well as a variety of neurotransmitter receptors, scaffolding proteins, and other effector molecules. Such recognition of the ever-evolving functions of synaptic cadherins may yield insight into the pathophysiology of brain disorders in which cadherins have been implicated and that manifest at different times of life.
Collapse
Affiliation(s)
- Lauren G Friedman
- Fishberg Department of Neuroscience, Friedman Brain Institute and the Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, USA
| | - Deanna L Benson
- Fishberg Department of Neuroscience, Friedman Brain Institute and the Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, USA
| | - George W Huntley
- Fishberg Department of Neuroscience, Friedman Brain Institute and the Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, USA.
| |
Collapse
|
9
|
Brusés JL. Cell surface localization of α3β4 nicotinic acetylcholine receptors is regulated by N-cadherin homotypic binding and actomyosin contractility. PLoS One 2013; 8:e62435. [PMID: 23626818 PMCID: PMC3633863 DOI: 10.1371/journal.pone.0062435] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 03/21/2013] [Indexed: 11/18/2022] Open
Abstract
Neuronal nicotinic acetylcholine receptors (nAChRs) are widely expressed throughout the central and peripheral nervous system and are localized at synaptic and extrasynaptic sites of the cell membrane. However, the mechanisms regulating the localization of nicotinic receptors in distinct domains of the cell membrane are not well understood. N-cadherin is a cell adhesion molecule that mediates homotypic binding between apposed cell membranes and regulates the actin cytoskeleton through protein interactions with the cytoplasmic domain. At synaptic contacts, N-cadherin is commonly localized adjacent to the active zone and the postsynaptic density, suggesting that N-cadherin contributes to the assembly of the synaptic complex. To examine whether N-cadherin homotypic binding regulates the cell surface localization of nicotinic receptors, this study used heterologous expression of N-cadherin and α3β4 nAChR subunits C-terminally fused to a myc-tag epitope in Chinese hamster ovary cells. Expression levels of α3β4 nAChRs at cell-cell contacts and at contact-free cell membrane were analyzed by confocal microscopy. α3β4 nAChRs were found distributed over the entire surface of contacting cells lacking N-cadherin. In contrast, N-cadherin-mediated cell-cell contacts were devoid of α3β4 nAChRs. Cell-cell contacts mediated by N-cadherin-deleted proteins lacking the β-catenin binding region or the entire cytoplasmic domain showed control levels of α3β4 nAChRs expression. Inhibition of actin polymerization with latrunculin A and cytochalasin D did not affect α3β4 nAChRs localization within N-cadherin-mediated cell-cell contacts. However, treatment with the Rho associated kinase inhibitor Y27632 resulted in a significant increase in α3β4 nAChR levels within N-cadherin-mediated cell-cell contacts. Analysis of α3β4 nAChRs localization in polarized Caco-2 cells showed specific expression on the apical cell membrane and colocalization with apical F-actin and the actin nucleator Arp3. These results indicate that actomyosin contractility downstream of N-cadherin homotypic binding regulates the cell surface localization of α3β4 nAChRs presumably through interactions with a particular pool of F-actin.
Collapse
Affiliation(s)
- Juan L Brusés
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, Kansas, United States of America.
| |
Collapse
|