Search results for "Tissue"

Protease‐activated receptor signaling in intestinal permeability regulation

2019

Protease-activated receptors (PARs) are a unique class of G-protein-coupled transmembrane receptors, which revolutionized the perception of proteases from degradative enzymes to context-specific signaling factors. Although PARs are traditionally known to affect several vascular responses, recent investigations have started to pinpoint the functional role of PAR signaling in the gastrointestinal (GI) tract. This organ is exposed to the highest number of proteases, either from the gut lumen or from the mucosa. Luminal proteases include the host's digestive enzymes and the proteases released by the commensal microbiota, while mucosal proteases entail extravascular clotting factors and the enzy…

Human R1441C LRRK2 regulates the synaptic vesicle proteome and phosphoproteome in a Drosophila model of Parkinson's disease

2016

International audience; Mutations in leucine-rich repeat kinase 2 (LRRK2) cause late-onset, autosomal dominant familial Parkinsons disease (PD) and variation at the LRRK2 locus contributes to the risk for idiopathic PD. LRRK2 can function as a protein kinase and mutations lead to increased kinase activity. To elucidate the pathophysiological mechanism of the R1441C mutation in the GTPase domain of LRRK2, we expressed human wild-type or R1441C LRRK2 in dopaminergic neurons of Drosophila and observe reduced locomotor activity, impaired survival and an age-dependent degeneration of dopaminergic neurons thereby creating a new PD-like model. To explore the function of LRRK2 variants in vivo, we …

Quantitative Proteomics Reveals Changes Induced by TIMP-3 on Cell Membrane Composition and Novel Metalloprotease Substrates

2021

Ectodomain shedding is a key mechanism of several biological processes, including cell-communication. Disintegrin and metalloproteinases (ADAMs), together with the membrane-type matrix metalloproteinases, play a pivotal role in shedding transmembrane proteins. Aberrant shedding is associated to several pathological conditions, including arthritis. Tissue inhibitor of metalloproteases 3 (TIMP-3), an endogenous inhibitor of ADAMs and matrix metalloproteases (MMPs), has been proven to be beneficial in such diseases. Thus, strategies to increase TIMP-3 bioavailability in the tissue have been sought for development of therapeutics. Nevertheless, high levels of TIMP-3 may lead to mechanism-based …

Innovative Approaches Using Lichen Enriched Media to Improve Isolation and Culturability of Lichen Associated Bacteria

2016

Lichens, self-supporting mutualistic associations between a fungal partner and one or more photosynthetic partners, also harbor non-photosynthetic bacteria. The diversity and contribution of these bacteria to the functioning of lichen symbiosis have recently begun to be studied, often by culture-independent techniques due to difficulties in their isolation and culture. However, culturing as yet unculturable lichenic bacteria is critical to unravel their potential functional roles in lichen symbiogenesis, to explore and exploit their biotechnological potential and for the description of new taxa. Our objective was to improve the recovery of lichen associated bacteria by developing novel isol…

Association between urticaria and nematode infections

2018

Background The association between parasites and urticaria was first suggested in the last century. A wide range, 0-75.4%, of the prevalence of parasitic infection has been reported with chronic urticaria (CU). Moreover, urticaria may be detected in patients with parasitosis. Nematodes are a type of helminth that infect hundreds of millions of people throughout the world. Objective The aim of this work was to collect and review the published studies and cases of urticaria associated with nematode infections. Methods A search of scientific literature data bases from January 1960 until May 2017 was carried out. Results Numerous nematode infections have been associated with urticaria and/or an…

2018

Background The expression and localization of transforming growth factor-β (TGF-β) pathway proteins in different compartments of the lower airways of patients with stable COPD is unclear. We aimed to determine TGF-β pathway protein expression in patients with stable COPD. Methods The expression and localization of TGF-β pathway components was measured in the bronchial mucosa and peripheral lungs of patients with stable COPD (n = 44), control smokers with normal lung function (n = 24), and control nonsmoking subjects (n = 11) using immunohistochemical analysis. Results TGF-β1, TGF-β3, and connective tissue growth factor expression were significantly decreased in the bronchiolar epithelium, w…

Blood group antigen A type 3 expression is a favorable prognostic factor in advanced NSCLC.

2015

Abstract Objectives Several blood group-related carbohydrate antigens are prognosis-relevant markers of tumor tissues. A type 3 (repetitive A) is a blood group antigen specific for A 1 erythrocytes. Its potential expression in tumor tissues has so far not been examined. Material and methods We have evaluated its expression in normal lung and in lung cancer using a novel antibody (A69-A/E8). For comparison an anti-A antibody specific to A types 1 and 2 was used, because its expression on lung cancer tissue has been previously reported to be of prognostic relevance. Resected tissue samples of 398 NSCLC patients were analyzed in immunohistochemistry using tissue microarrays. Results and conclu…

Functional characterization of a novel 3D model of the epithelial-mesenchymal trophic unit

2017

Background/Aim: Epithelial-mesenchymal communication plays a key role in tissue homeostasis and abnormal signaling contributes to chronic airways disease such as COPD. Most in vitro models are limited in complexity and poorly represent this epithelial-mesenchymal trophic unit. We postulated that cellular outgrowth from bronchial tissue would enable development of a mucosal structure that recapitulates better in vivo tissue architecture. Materials and Methods: Bronchial tissue was embedded in Matrigel and outgrowth cultures monitored using time-lapse microscopy, electrical resistance, light and electron microscopy. Cultures were challenged repetitively with cigarette smoke extract (CSE). Res…

Endogenous β-neurexins on axons and within synapses show regulated dynamic behavior

2021

Summary: Neurexins are key organizer molecules that regulate synaptic function and are implicated in autism and schizophrenia. β-neurexins interact with numerous cell adhesion and receptor molecules, but their neuronal localization remains elusive. Using single-molecule tracking and high-resolution microscopy to detect neurexin1β and neurexin3β in primary hippocampal neurons from knockin mice, we demonstrate that endogenous β-neurexins are present in fewer than half of excitatory and inhibitory synapses. Moreover, we observe a large extrasynaptic pool of β-neurexins on axons and show that axonal β-neurexins diffuse with higher surface mobility than those transiently confined within synapses…

Small Rab GTPases in Intracellular Vesicle Trafficking: The Case of Rab3A/Raphillin-3A Complex in the Kidney

2021

Small Rab GTPases, the largest group of small monomeric GTPases, regulate vesicle trafficking in cells, which are integral to many cellular processes. Their role in neurological diseases, such as cancer and inflammation have been extensively studied, but their implication in kidney disease has not been researched in depth. Rab3a and its effector Rabphillin-3A (Rph3A) expression have been demonstrated to be present in the podocytes of normal kidneys of mice rats and humans, around vesicles contained in the foot processes, and they are overexpressed in diseases with proteinuria. In addition, the Rab3A knockout mice model induced profound cytoskeletal changes in podocytes of high glucose fed a…