Search results for "membrane"
showing 10 items of 4477 documents
IL-10-Modulated Human Dendritic Cells for Clinical Use: Identification of a Stable and Migratory Subset with Improved Tolerogenic Activity.
2015
Abstract Dendritic cells (DCs) are key regulators of protective immune responses and tolerance to (self-)Ags. Therefore, the scientific rationale for the use of tolerogenic DC therapy in the fields of allergies, autoimmunity, and transplantation medicine is strong. In this study, we analyzed the tolerogenic capacity of IL-10–modulated DC (IL-10DC) subpopulations to identify a DC subset that combines potent immunosuppressive activities with valuable immune properties for clinical implementation. IL-10DCs consist of two phenotypically distinct subpopulations: CD83highCCR7+ IL-10DCs and CD83lowCCR7− IL-10DCs. Suppressor assays with activated effector T cells revealed that CD4+ regulatory T cel…
COVID-19: viral–host interactome analyzed by network based-approach model to study pathogenesis of SARS-CoV-2 infection
2020
AbstractBackgroundEpidemiological, virological and pathogenetic characteristics of SARS-CoV-2 infection are under evaluation. A better understanding of the pathophysiology associated with COVID-19 is crucial to improve treatment modalities and to develop effective prevention strategies. Transcriptomic and proteomic data on the host response against SARS-CoV-2 still have anecdotic character; currently available data from other coronavirus infections are therefore a key source of information.MethodsWe investigated selected molecular aspects of three human coronavirus (HCoV) infections, namely SARS-CoV, MERS-CoV and HCoV-229E, through a network based-approach. A functional analysis of HCoV-hos…
A rare association of chronic lymphocytic leukemia with c-ANCA-positive Wegener’s granulomatosis: a case report
2016
Background Wegener’s granulomatosis is a systemic vasculitis of the small- and medium-sized vessels, produced by the action of ANCA, which involves the respiratory tract, kidneys, and eyes, with a potential for lethal evolution in the first year after diagnosis. Its association with chronic lymphocytic leukemia is rarely described in the literature, and it may be difficult to diagnose and to treat this association. Case presentation We present the case of a 73-year-old Caucasian patient, a rare case in which Wegener’s granulomatosis is associated in a patient with chronic lymphocytic leukemia, who is admitted in the Infectious Disease Department for fever, diplopia, headache, purulent and h…
Mg2+ homeostasis and transport in cyanobacteria – at the crossroads of bacterial and chloroplast Mg2+ import
2018
Abstract Magnesium cation (Mg2+) is the most abundant divalent cation in living cells, where it is required for various intracellular functions. In chloroplasts and cyanobacteria, established photosynthetic model systems, Mg2+ is the central ion in chlorophylls, and Mg2+ flux across the thylakoid membrane is required for counterbalancing the light-induced generation of a ΔpH across the thylakoid membrane. Yet, not much is known about Mg2+ homoeostasis, transport and distribution within cyanobacteria. However, Mg2+ transport across membranes has been studied in non-photosynthetic bacteria, and first observations and findings are reported for chloroplasts. Cyanobacterial cytoplasmic membranes…
Organization into Higher Ordered Ring Structures Counteracts Membrane Binding of IM30, a Protein Associated with Inner Membranes in Chloroplasts and …
2016
The IM30 (inner membrane-associated protein of 30 kDa), also known as the Vipp1 (vesicle-inducing protein in plastids 1), has a crucial role in thylakoid membrane biogenesis and maintenance. Recent results suggest that the protein binds peripherally to membranes containing negatively charged lipids. However, although IM30 monomers interact and assemble into large oligomeric ring complexes with different numbers of monomers, it is still an open question whether ring formation is crucial for membrane interaction. Here we show that binding of IM30 rings to negatively charged phosphatidylglycerol membrane surfaces results in a higher ordered membrane state, both in the head group and in the inn…
Proton Leakage Is Sensed by IM30 and Activates IM30-Triggered Membrane Fusion
2020
The inner membrane-associated protein of 30 kDa (IM30) is crucial for the development and maintenance of the thylakoid membrane system in chloroplasts and cyanobacteria. While its exact physiological function still is under debate, it has recently been suggested that IM30 has (at least) a dual function, and the protein is involved in stabilization of the thylakoid membrane as well as in Mg2+-dependent membrane fusion. IM30 binds to negatively charged membrane lipids, preferentially at stressed membrane regions where protons potentially leak out from the thylakoid lumen into the chloroplast stroma or the cyanobacterial cytoplasm, respectively. Here we show in vitro that IM30 membrane binding…
Staining SDS-PAGE gels of skeletal matrices after western blot: a way to improve their sharpness.
2015
7 pages; International audience; Denaturing 1D electrophoresis on acrylamide gels - also referred as SDS-PAGE - is a classical technique for fractionating and visualizing the macromolecular constituents of matrices associated to calcified tissues. This technique has been widely used in association with the subsequent silver nitrate staining. But because matrices associated to calcified tissues are very often glycosylated and constituted of numerous polydisperse macromolecules, the obtained pattern is frequently 'smeary' and discrete bands, when present on the gel, are often blurred, thickened or totally masked by the polydisperse macromolecules. In this paper, we present a simple protocol t…
Biophysical and functional characterization of the human olfactory receptor OR1A1 expressed in a mammalian inducible cell line
2014
International audience; Olfactory receptors (ORs) play a crucial role in detecting the odorant molecules present in the surrounding environment. These receptors, which belong to class A G-protein-coupled receptors, constitute the largest transmembrane protein family in the human genome. Functional studies showed that the OR family includes members that are able to respond to a large set of odorants and members that are activated by a relatively small number of related odorants. To understand the molecular mechanisms that govern the receptor-ligand interactions, we overexpressed the human OR hOR1A1 in a stable tetracycline-inducible HEK293S cell line. This receptor was engineered by insertin…
Enhanced autophagic-lysosomal activity and increased BAG3-mediated selective macroautophagy as adaptive response of neuronal cells to chronic oxidati…
2019
Oxidative stress and a disturbed cellular protein homeostasis (proteostasis) belong to the most important hallmarks of aging and of neurodegenerative disorders. The proteasomal and autophagic-lysosomal degradation pathways are key measures to maintain proteostasis. Here, we report that hippocampal cells selected for full adaptation and resistance to oxidative stress induced by hydrogen peroxide (oxidative stress-resistant cells, OxSR cells) showed a massive increase in the expression of components of the cellular autophagic-lysosomal network and a significantly higher overall autophagic activity. A comparative expression analysis revealed that distinct key regulators of autophagy are upregu…
Artemisinin-treatment in pre-symptomatic APP-PS1 mice increases gephyrin phosphorylation at Ser270: a modification regulating postsynaptic GABAAR den…
2021
Abstract Artemisinins, a group of plant-derived sesquiterpene lactones, are efficient antimalarial agents. They also share anti-inflammatory and anti-viral activities and were considered for treatment of neurodegenerative disorders like Alzheimer’s disease (AD). Additionally, artemisinins bind to gephyrin, the multifunctional scaffold of GABAergic synapses, and modulate inhibitory neurotransmission in vitro. We previously reported an increased expression of gephyrin and GABAA receptors in early pre-symptomatic stages of an AD mouse model (APP-PS1) and in parallel enhanced CDK5-dependent phosphorylation of gephyrin at S270. Here, we studied the effects of artemisinin on gephyrin in the brain…