scholarly journals Interplay between Anakonda, Gliotactin and M6 for tricellular junction assembly and anchoring of septate junctions in Drosophila epithelium

2020 ◽  
Author(s):  
Thomas Esmangart de Bournonville ◽  
Roland Le Borgne
Keyword(s):  
Barrier Function ◽  
Adherens Junctions ◽  
Proteolipid Protein ◽  
Tissue Homeostasis ◽  
Septate Junctions ◽  
Tissue Integrity ◽  
Mechanical Signals ◽  
Complex Process ◽  
Tensile Forces

SummaryIn epithelia, Tricellular junctions (TCJs) serve as pivotal sites for barrier function and integration of both biochemical and mechanical signals. While essential for tissue homeostasis, TCJ assembly, composition and links to adjacent bicellular junctions (BCJs) remain poorly understood. Here we have characterized the assembly of TCJs within the plane of adherens junctions (tAJ) and the plane of septate junctions (tSJ) in Drosophila and report that their formation is spatiotemporally decoupled. The assembly and stabilization of previously described tSJ components Anakonda (Aka) and Gliotactin (Gli) as well as the newly reported tSJ proteolipid protein M6, is shown to be a complex process. Aka and M6, whose localization is interdependent, act upstream to locate Gli. In turn, Gli stabilizes Aka at tSJ. Those results unravel a previous unknown role of M6 at tSJ and a tight interplay between tSJ components to assemble and maintain tSJs. In addition, tSJ components are not only essential at vertex as we found that loss of tSJ integrity also induces micron-length bicellular SJs deformations that are free of tensile forces. This phenotype is associated with the disappearance of SJ components at tricellular contacts, indicating that bSJ are no longer connected to tSJs. Reciprocally, SJ components are in turn required to restrict the localization of Aka and Gli at vertex. We propose that tSJs function as pillars to anchor bSJs to ensure the maintenance of tissue integrity in Drosophila proliferative epithelia.

Questions on the role of biofilms for the adaptation of microorganisms to unfavorable environmental factors by the example of P. aeruginosa

2020 ◽  
Vol 99 (4) ◽  
pp. 379-383
Author(s):  
Vasily N. Afonyushkin ◽  
N. A. Donchenko ◽  
Ju. N. Kozlova ◽  
N. A. Davidova ◽  
V. Yu. Koptev ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Environmental Factors ◽  
Barrier Function ◽  
Infectious Agent ◽  
Antagonistic Activity ◽  
The Body ◽  
Main Function ◽  
Pathogenic Potential ◽  
The Face

Pseudomonas aeruginosa is a widely represented species of bacteria possessing of a pathogenic potential. This infectious agent is causing wound infections, fibrotic cystitis, fibrosing pneumonia, bacterial sepsis, etc. The microorganism is highly resistant to antiseptics, disinfectants, immune system responses of the body. The responses of a quorum sense of this kind of bacteria ensure the inclusion of many pathogenicity factors. The analysis of the scientific literature made it possible to formulate four questions concerning the role of biofilms for the adaptation of P. aeruginosa to adverse environmental factors: Is another person appears to be predominantly of a source an etiological agent or the source of P. aeruginosa infection in the environment? Does the formation of biofilms influence on the antibiotic resistance? How the antagonistic activity of microorganisms is realized in biofilm form? What is the main function of biofilms in the functioning of bacteria? A hypothesis has been put forward the effect of biofilms on the increase of antibiotic resistance of bacteria and, in particular, P. aeruginosa to be secondary in charcter. It is more likely a biofilmboth to fulfill the function of storing nutrients and provide topical competition in the face of food scarcity. In connection with the incompatibility of the molecular radii of most antibiotics and pores in biofilm, biofilm is doubtful to be capable of performing a barrier function for protecting against antibiotics. However, with respect to antibodies and immunocompetent cells, the barrier function is beyond doubt. The biofilm is more likely to fulfill the function of storing nutrients and providing topical competition in conditions of scarcity of food resources.

Social Cohesion, Breaks, and Transformations in Italy, 535–600

2018 ◽  
Author(s):  
Walter Pohl
Keyword(s):  
The Political ◽  
Late Antique ◽  
Religious Context ◽  
Ancient Society ◽  
Complex Process ◽  
Term Change ◽  
Two Generations ◽  
Classical Culture

When the Gothic War began in Italy in 535, the country still conserved many features of classical culture and late antique administration. Much of that was lost in the political upheavals of the following decades. Building on Chris Wickham’s work, this contribution sketches an integrated perspective of these changes, attempting to relate the contingency of events to the logic of long-term change, discussing political options in relation to military and economic means, and asking in what ways the erosion of consensus may be understood in a cultural and religious context. What was the role of military entrepreneurs of more or less barbarian or Roman extraction in the distribution or destruction of resources? How did Christianity contribute to the transformation of ancient society? The old model of barbarian invasions can contribute little to understanding this complex process. It is remarkable that for two generations, all political strategies in Italy ultimately failed.

scholarly journals STAT3 Signalling via the IL-6ST/gp130 Cytokine Receptor Promotes Epithelial Integrity and Intestinal Barrier Function during DSS-Induced Colitis

Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 187
Author(s):  
Lokman Pang ◽  
Jennifer Huynh ◽  
Mariah G. Alorro ◽  
Xia Li ◽  
Matthias Ernst ◽  
...  
Keyword(s):  
Barrier Function ◽  
Intestinal Barrier ◽  
Intestinal Barrier Function ◽  
Intestinal Epithelial ◽  
Barrier Dysfunction ◽  
Epithelial Integrity ◽  
Barrier Integrity ◽  
Gp130 Receptor ◽  
Stat3 Signalling

The intestinal epithelium provides a barrier against commensal and pathogenic microorganisms. Barrier dysfunction promotes chronic inflammation, which can drive the pathogenesis of inflammatory bowel disease (IBD) and colorectal cancer (CRC). Although the Signal Transducer and Activator of Transcription-3 (STAT3) is overexpressed in both intestinal epithelial cells and immune cells in IBD patients, the role of the interleukin (IL)-6 family of cytokines through the shared IL-6ST/gp130 receptor and its associated STAT3 signalling in intestinal barrier integrity is unclear. We therefore investigated the role of STAT3 in retaining epithelial barrier integrity using dextran sulfate sodium (DSS)-induced colitis in two genetically modified mouse models, to either reduce STAT1/3 activation in response to IL-6 family cytokines with a truncated gp130∆STAT allele (GP130∆STAT/+), or by inducing short hairpin-mediated knockdown of Stat3 (shStat3). Here, we show that mice with reduced STAT3 activity are highly susceptible to DSS-induced colitis. Mechanistically, the IL-6/gp130/STAT3 signalling cascade orchestrates intestinal barrier function by modulating cytokine secretion and promoting epithelial integrity to maintain a defence against bacteria. Our study also identifies a crucial role of STAT3 in controlling intestinal permeability through tight junction proteins. Thus, therapeutically targeting the IL-6/gp130/STAT3 signalling axis to promote barrier function may serve as a treatment strategy for IBD patients.

scholarly journals Consciousness, decision making, and volition: freedom beyond chance and necessity

2021 ◽  
Author(s):  
Hans Liljenström
Keyword(s):  
Decision Making ◽  
Free Will ◽  
Brain Activity ◽  
Brain Structures ◽  
Complex Process ◽  
Neural Information ◽  
Neural Information Processing ◽  
Stochastic Population Model ◽  
The Brain

AbstractWhat is the role of consciousness in volition and decision-making? Are our actions fully determined by brain activity preceding our decisions to act, or can consciousness instead affect the brain activity leading to action? This has been much debated in philosophy, but also in science since the famous experiments by Libet in the 1980s, where the current most common interpretation is that conscious free will is an illusion. It seems that the brain knows, up to several seconds in advance what “you” decide to do. These studies have, however, been criticized, and alternative interpretations of the experiments can be given, some of which are discussed in this paper. In an attempt to elucidate the processes involved in decision-making (DM), as an essential part of volition, we have developed a computational model of relevant brain structures and their neurodynamics. While DM is a complex process, we have particularly focused on the amygdala and orbitofrontal cortex (OFC) for its emotional, and the lateral prefrontal cortex (LPFC) for its cognitive aspects. In this paper, we present a stochastic population model representing the neural information processing of DM. Simulation results seem to confirm the notion that if decisions have to be made fast, emotional processes and aspects dominate, while rational processes are more time consuming and may result in a delayed decision. Finally, some limitations of current science and computational modeling will be discussed, hinting at a future development of science, where consciousness and free will may add to chance and necessity as explanation for what happens in the world.

scholarly journals Pivotal role of MUC1 glycosylation by cigarette smoke in modulating disruption of airway adherens junctions in vitro

2014 ◽  
Vol 234 (1) ◽  
pp. 60-73 ◽  
Author(s):  
Lili Zhang ◽  
Marianne Gallup ◽  
Lorna Zlock ◽  
Yu Ting Feeling Chen ◽  
Walter E Finkbeiner ◽  
...  
Keyword(s):  
Cigarette Smoke ◽  
Adherens Junctions ◽  
Pivotal Role

scholarly journals Az ösztrogénmetabolom biológiai és klinikai jelentősége lokális folyamatokban

2017 ◽  
Vol 158 (24) ◽  
pp. 929-937
Author(s):  
Krisztián Kovács ◽  
Barna Vásárhelyi ◽  
Katalin Mészáros ◽  
Attila Patócs ◽  
Gellért Karvaly
Keyword(s):  
Biological Activity ◽  
Clinical Significance ◽  
Physiological Role ◽  
Tissue Homeostasis ◽  
Diagnostic Significance ◽  
Peripheral Tissues ◽  
Breakdown Process ◽  
Specific Manner ◽  
Related Compounds

Abstract: Considerable knowledge has been gathered on the physiological role of estrogens. However, fairly little information is available on the role of compounds produced in the breakdown process of estrone and estradiol wich may play a role in various diseases associated with estrogen impact. To date, approximately 15 extragonadal estrogen-related compounds have been identified. These metabolites may exert protective, or, instead, pro-inflammatory and/or pro-oncogenic activity in a tissue-specific manner. Systemic and local estrogen metabolite levels are not necesserily correlated, which may promote the diagnostic significance of the locally produced estrogen metabolites in the future. The aim of the present study is a bibliographic review of the extragonadal metabolome in peripheral tissues, and to highlight the role of the peripheral tissue homeostasis of estrogens as well as the non-hormonal biological activity and clinical significance of the estrogen metabolome. Orv Hetil. 2017; 158(24): 929–937.

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