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Apical polarity

Jae Seung Yang, Jun Ho Jeon, Mi Seon Jang, Seok-Seong Kang, Ki Bum Ahn, Manki Song, Cheol-Heui Yun, Seung Hyun Han
Although Vibrio cholerae colonizes the small intestine and induces acute inflammatory responses, less is known about the molecular mechanisms of V. cholerae-induced inflammatory responses in the intestine. We recently reported that OmpU, one of the most abundant outer membrane proteins of V. cholerae, plays an important role in the innate immunity of the whole bacteria. In this study, we evaluated the role of OmpU in induction of IL-8, a representative chemokine that recruits various inflammatory immune cells, in the human intestinal epithelial cell (IEC) line, HT-29...
November 13, 2017: Molecular Immunology
Wang Xi, Surabhi Sonam, Thuan Beng Saw, Benoit Ladoux, Chwee Teck Lim
Collective epithelial behaviors are essential for the development of lumens in organs. However, conventional assays of planar systems fail to replicate cell cohorts of tubular structures that advance in concerted ways on out-of-plane curved and confined surfaces, such as ductal elongation in vivo. Here, we mimic such coordinated tissue migration by forming lumens of epithelial cell sheets inside microtubes of 1-10 cell lengths in diameter. We show that these cell tubes reproduce the physiological apical-basal polarity, and have actin alignment, cell orientation, tissue organization, and migration modes that depend on the extent of tubular confinement and/or curvature...
November 15, 2017: Nature Communications
Mikiko Nagashima, Jeremy Hadidjojo, Linda K Barthel, David K Lubensky, Pamela A Raymond
BACKGROUND: The multiplex, lattice mosaic of cone photoreceptors in the adult fish retina is a compelling example of a highly ordered epithelial cell pattern, with single cell width rows and columns of cones and precisely defined neighbor relationships among different cone types. Cellular mechanisms patterning this multiplex mosaic are not understood. Physical models can provide new insights into fundamental mechanisms of biological patterning. In earlier work, we developed a mathematical model of photoreceptor cell packing in the zebrafish retina, which predicted that anisotropic mechanical tension in the retinal epithelium orients planar polarized adhesive interfaces to align the columns as cone photoreceptors are generated at the retinal margin during post-embryonic growth...
November 15, 2017: Neural Development
Alejandra I Romero-Morales, Natalya A Ortolano, Vivian Gama
Establishment of apico-basal polarity is critical for the lumenal epiblast-like morphogenesis of human pluripotent stem cells (hPSCs). In this issue, Taniguchi et al. (2017. J Cell Biol. describe a structure called the apicosome, generated in single hPSCs, that allows them to self-organize and form the lumenal epiblast-like stage.
November 14, 2017: Journal of Cell Biology
Chantal Roubinet, Anna Tsankova, Tri Thanh Pham, Arnaud Monnard, Emmanuel Caussinus, Markus Affolter, Clemens Cabernard
Asymmetric cell division, creating sibling cells with distinct developmental potentials, can be manifested in sibling cell size asymmetry. This form of physical asymmetry occurs in several metazoan cells, but the underlying mechanisms and function are incompletely understood. Here we use Drosophila neural stem cells to elucidate the mechanisms involved in physical asymmetry establishment. We show that Myosin relocalizes to the cleavage furrow via two distinct cortical Myosin flows: at anaphase onset, a polarity induced, basally directed Myosin flow clears Myosin from the apical cortex...
November 9, 2017: Nature Communications
Claire Colas, Masayuki Masuda, Kazuaki Sugio, Seiji Miyauchi, Yongjun Hu, David E Smith, Avner Schlessinger
In humans, peptides derived from dietary proteins and peptide-like drugs are transported via the proton-dependent oligopeptide transporter hPepT1 (SLC15A1). hPepT1 is located across the apical membranes of the small intestine and kidney, where it serves as a high-capacity low-affinity transporter of a broad range of di- and tri-peptides. hPepT1 is also overexpressed in the colon of Inflammatory Bowel Disease (IBD) patients, where it mediates the transport of harmful peptides of bacterial origin. Therefore, hPepT1 is a drug target for prodrug substrates interacting with intracellular protein or inhibitors blocking the transport of toxic bacterial products...
November 7, 2017: Molecular Pharmaceutics
Eric Bailly, Alexandra Walton, Jean-Paul Borg
Planar cell polarity (PCP) refers to the capacity of a tissue, typically, but not exclusively, an epithelium, to transmit directional information across the tissue plane such that its cellular constituents can differentiate, divide or move in a coordinated manner and along a common axis, generally orthogonal to the apical-basal axis. PCP relies on a core module of highly conserved proteins originally identified in Drosophila which can act intra- and extracellularly. In this review, we focuse on the vertebrate ortholog of one of these core PCP components, namely the Vangl2 protein...
October 27, 2017: Seminars in Cell & Developmental Biology
Kaceauy VanderVorst, Jason Hatakeyama, Anastasia Berg, Hyun Lee, Kermit L Carraway
While the mutational activation of oncogenes drives tumor initiation and growth by promoting cellular transformation and proliferation, increasing evidence suggests that the subsequent re-engagement of largely dormant developmental pathways contributes to cellular phenotypes associated with the malignancy of solid tumors. Genetic studies from a variety of organisms have defined many of the components that maintain epithelial planar cell polarity (PCP), or cellular polarity in the axis orthogonal to the apical-basal axis...
October 26, 2017: Seminars in Cell & Developmental Biology
Matthias Rübsam, Aaron F Mertz, Akiharu Kubo, Susanna Marg, Christian Jüngst, Gladiola Goranci-Buzhala, Astrid C Schauss, Valerie Horsley, Eric R Dufresne, Markus Moser, Wolfgang Ziegler, Masayuki Amagai, Sara A Wickström, Carien M Niessen
Generation of a barrier in multi-layered epithelia like the epidermis requires restricted positioning of functional tight junctions (TJ) to the most suprabasal viable layer. This positioning necessitates tissue-level polarization of junctions and the cytoskeleton through unknown mechanisms. Using quantitative whole-mount imaging, genetic ablation, and traction force microscopy and atomic force microscopy, we find that ubiquitously localized E-cadherin coordinates tissue polarization of tension-bearing adherens junction (AJ) and F-actin organization to allow formation of an apical TJ network only in the uppermost viable layer...
November 1, 2017: Nature Communications
Isobel Massie, Kristina Spaniol, Andreas Barbian, Gereon Poschmann, Kai Stühler, Gerd Geerling, Marco Metzger, Sonja Mertsch, Stefan Schrader
Purpose: Dry eye syndrome (DES) can cause blindness in severe cases, but mainly palliative treatments exist. A tissue-engineered lacrimal gland (LG) could provide a curative treatment. We aimed to evaluate decellularized porcine jejunum (SIS-Muc) as a scaffold for porcine LG epithelial cells. Methods: To evaluate SIS-Muc as a potential scaffold, basement membrane proteins in SIS-Muc and native LG were compared (immunohistochemistry [IHC]). Porcine LG epithelial cells cultured on plastic were characterized (immunocytochemistry), and their culture supernatant was compared with porcine tears (proteomics)...
October 1, 2017: Investigative Ophthalmology & Visual Science
Fabrizio Araniti, Leonardo Bruno, Francesco Sunseri, Marianna Pacenza, Ivano Forgione, Maria Beatrice Bitonti, Maria Rosa Abenavoli
Farnesene is a sesquiterpene with semiochemical activity involved in interspecies communication. This molecule, known for its phytotoxic potential and its effects on root morphology and anatomy, caused anisotropic growth, bold roots and a "left-handedness" phenotype. These clues suggested an alteration of auxin distribution, and for this reason, the aim of the present study was to evaluate its effects on: i) PIN-FORMED proteins (PIN) distribution, involved in polar auxin transport; ii) PIN genes expression iii) apical meristem anatomy of primary root, in 7 days old Arabidopsis thaliana seedlings treated with farnesene 250 μM...
October 19, 2017: Plant Physiology and Biochemistry: PPB
Jesús Gómez-Escudero, Vanessa Moreno, Mara Martín-Alonso, M Victoria Hernández de Riquer, Tamar Feinberg, Ángel Colmenar, Enrique Calvo, Emilio Camafeita, Fernando Martínez, Menno J Oudhoff, Stephen J Weiss, Alicia G Arroyo
Cadherin-based intercellular adhesions are essential players in epithelial homeostasis, but their dynamic regulation during tissue morphogenesis and remodeling remain largely undefined. Herein, we characterize an unexpected role for the membrane-anchored metalloproteinase MT2-MMP in regulating epithelial cell quiescence. Following co-immunoprecipitation and mass spectrometry, the MT2-MMP cytosolic tail was found to interact with the zonula occludens protein-1 (ZO-1) at the apical junctions of polarized epithelial cells...
October 23, 2017: Journal of Cell Science
Zarah M Löf-Öhlin, Pia Nyeng, Matthew E Bechard, Katja Hess, Eric Bankaitis, Thomas U Greiner, Jacqueline Ameri, Christopher V Wright, Henrik Semb
Apicobasal polarity is known to affect epithelial morphogenesis and cell differentiation, but it remains unknown how these processes are mechanistically orchestrated. We find that ligand-specific EGFR signalling via PI(3)K and Rac1 autonomously modulates apicobasal polarity to enforce the sequential control of morphogenesis and cell differentiation. Initially, EGF controls pancreatic tubulogenesis by negatively regulating apical polarity induction. Subsequently, betacellulin, working via inhibition of atypical protein kinase C (aPKC), causes apical domain constriction within neurogenin3(+) endocrine progenitors, which results in reduced Notch signalling, increased neurogenin3 expression, and β-cell differentiation...
November 2017: Nature Cell Biology
Nima Mesbah Ardakani, Nathan Tobias Harvey, Vanessa Mansford, Benjamin Andrew Wood
Basal cell carcinoma (BCC) is the most common cutaneous malignancy, comprising approximately 75%-80% of all skin cancers. Surgical excision is the most common first line treatment modality, with the intent of obtaining clear margins. If the initial excision is incomplete or inadequate, a re-excision will often be performed in an attempt to achieve histological clearance. The pathological examination of these specimens requires a balance between the need for adequate assessment and efficient use of laboratory resources...
November 2017: American Journal of Dermatopathology
Elsa Bazellières, Veronika Aksenova, Magali Barthélémy-Requin, Dominique Massey-Harroche, André Le Bivic
Epithelial cell organization relies on a set of proteins that interact in an intricate way and which are called polarity complexes. These complexes are involved in the determination of the apico-basal axis and in the positioning and stability of the cell-cell junctions called adherens junctions at the apico-lateral border in invertebrates. Among the polarity complexes, two are present at the apical side of epithelial cells. These are the Par complex including aPKC, PAR3 and PAR6 and the Crumbs complex including, CRUMBS, PALS1 and PATJ/MUPP1...
October 19, 2017: Seminars in Cell & Developmental Biology
Simona Paladino, Stephanie Lebreton, Mickaël Lelek, Patrizia Riccio, Sergio De Nicola, Christophe Zimmer, Chiara Zurzolo
Spatio-temporal compartmentalization of membrane proteins is critical for the regulation of diverse vital functions in eukaryotic cells. It was previously shown that, at the apical surface of polarized MDCK cells, glycosylphosphatidylinositol (GPI)-anchored proteins (GPI-APs) are organized in small cholesterol-independent clusters of single GPI-AP species (homoclusters), which are required for the formation of larger cholesterol-dependent clusters formed by multiple GPI-APs species (heteroclusters). This clustered organization is crucial for the biological activities of GPI-APs, hence, understanding the spatio-temporal properties of their membrane organization is of fundamental importance...
October 18, 2017: Biochemical Journal
Stefan Nehls, Andreas Janshoff
The mechanical response of adherent, polarized cells to indentation is frequently attributed to the presence of an endogenous actin cortex attached to the inner leaflet of the plasma membrane. Here, we scrutinized the elastic properties of apical membranes separated from living cells and attached to a porous mesh in the absence of intracellular factors originating from the cytosol, organelles, the substrate, neighbors, and the nucleus. We found that a tension-based model describes the data very well providing essentially the prestress of the shell generated by adhesion of the apical membrane patches to the pore rim and the apparent area compressibility modulus, an intrinsic elastic modulus modulated by the surface excess stored in membrane reservoirs...
October 17, 2017: Biophysical Journal
Alexander X Cartagena-Rivera, Christina M Van Itallie, James M Anderson, Richard S Chadwick
Maintenance of epithelial tissue integrity requires coordination between cell-cell adherens junctions, tight junctions (TJ), and the perijunctional actomyosin cytoskeleton. Here we addressed the hypothesis that alterations in TJ structure and remodeling of the actomyosin cytoskeleton modify epithelial mechanics. Current methods to measure supracellular mechanical properties disrupt intact monolayers, therefore, we developed a novel method using noncontact acoustic frequency-modulation atomic force microscopy (FM-AFM) and tested it on MDCK polarized monolayers...
October 18, 2017: Nature Communications
Koji Nakaya, Masahisa Onoguchi, Yoshihiro Nishimua, Keisuke Kiso, Hideki Otsuka, Yoshifumi Nouno, Takayuki Shibutani, Eisuke Yasuda
Background: Prone single photon emission computed tomography (SPECT) is suitable for evaluating the cardiac inferior wall as it suppresses attenuation artifacts from the diaphragm. The solid-state dedicated cardiac camera (D-SPECT) allows upright imaging, which can also be used to avoid attenuation artifacts from the diaphragm. We compared prone and upright imaging for inferior wall evaluation using (201)TlCl myocardial perfusion SPECT. Methods: The study targeted 45 patients. The prone imaging group included 23 subjects who underwent additional prone imaging because supine imaging indicated that the inferior wall had reduced uptake...
October 17, 2017: Journal of Nuclear Medicine Technology
Meng Zhu, Chuen Yan Leung, Marta N Shahbazi, Magdalena Zernicka-Goetz
Establishment of cell polarity in the mammalian embryo is fundamental for the first cell fate decision that sets aside progenitor cells for both the new organism and the placenta. Yet the sequence of events and molecular mechanism that trigger this process remain unknown. Here, we show that de novo polarisation of the mouse embryo occurs in two distinct phases at the 8-cell stage. In the first phase, an apical actomyosin network is formed. This is a pre-requisite for the second phase, in which the Par complex localises to the apical domain, excluding actomyosin and forming a mature apical cap...
October 13, 2017: Nature Communications
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