Search results for "Acellular"

Different intracellular cation-content present in right and left ventricle dependent on varying extracellular Ca2+-concentrations.

1979

Abstract The different intracellular cation-contents present in the right and left ventricle depend on varying Ca2+-concentrations. The effect of extracellular Ca2+-concentrations varied within the physiological range has been studied on an isolated guinea pig heart preparation, showing excellent stable experimental conditions. By increasing the extracellular Ca2+-concentration from 0.45 m m to 3.6 m m the tissue contents of calcium and potassium were increased dependent on [Ca]e whereas that of Na was reduced. This was due to a change in the composition of the intracellular cations as the extracellular space (inulin) and water-content of the heart muscle tissue were not influenced by incre…

Expansion of intracellular IFN-γ positive lymphocytes during Mycoplasma agalactiae infection in sheep.

2010

Abstract A method to assess the expansion of antigen-specific intracellular IFN-γ positive T cell subsets during the infection will be helpful for a better understanding of mycoplasmal infections physiopathology in the sheep. We analysed the percentage of antigen-specific lymphocytes positive for intracellular IFN-γ during the infection of sheep with Mycoplasma agalactiae by culturing peripheral blood mononuclear cells of infected or uninfected animals with irradiated M. agalactiae . The expansion of antigen-specific IFN-γ positive lymphocytes in infected sheep was initially sustained by CD4 + T cells at day 15 after infection, when antigen specific IgG start to be detectable, followed by C…

Defective stromal remodeling and neutrophil extracellular traps in lymphoid tissues favor the transition from autoimmunity to lymphoma

2013

Abstract Altered expression of matricellular proteins can become pathogenic in the presence of persistent perturbations in tissue homeostasis. Here, we show that autoimmunity associated with Fas mutation was exacerbated and transitioned to lymphomagenesis in the absence of SPARC (secreted protein acidic rich in cysteine). The absence of SPARC resulted in defective collagen assembly, with uneven compartmentalization of lymphoid and myeloid populations within secondary lymphoid organs (SLO), and faulty delivery of inhibitory signals from the extracellular matrix. These conditions promoted aberrant interactions between neutrophil extracellular traps and CD5+ B cells, which underwent malignant …

Neutrophil extracellular traps mediate transfer of cytoplasmic neutrophil antigens to myeloid dendritic cells toward ANCA induction and associated au…

2012

AbstractAntineutrophil cytoplasmic antibodies (ANCAs) target proteins normally retained within neutrophils, indicating that cell death is involved in the autoimmunity process. Still, ANCA pathogenesis remains obscure. ANCAs activate neutrophils inducing their respiratory burst and a peculiar form of cell death, named NETosis, characterized by formation of neutrophil extracellular traps (NETs), decondensed chromatin threads decorated with cytoplasmic proteins endorsed with antimicrobial activity. NETs have been consistently detected in ANCA-associated small-vessel vasculitis, and this association prompted us to test whether the peculiar structure of NET favors neutrophil proteins uploading i…

PCSK9 Confers Inflammatory Properties to Extracellular Vesicles Released by Vascular Smooth Muscle Cells

2022

Vascular smooth muscle cells (VSMCs) are key participants in both early- and late-stage atherosclerosis and influence neighbouring cells possibly by means of bioactive molecules, some of which are packed into extracellular vesicles (EVs). Proprotein convertase subtilisin/kexin type 9 (PCSK9) is expressed and secreted by VSMCs. This study aimed to unravel the role of PCSK9 on VSMCs-derived EVs in terms of content and functionality. EVs were isolated from human VSMCs overexpressing human PCSK9 (VSMCPCSK9-EVs) and tested on endothelial cells, monocytes, macrophages and in a model of zebrafish embryos. Compared to EVs released from wild-type VSMCs, VSMCPCSK9-EVs caused a rise in the expression …

G.P.199

2014

Our group has recently derived skeletal muscle from dermis-derived cells, by using an extracellular matrix that recreates the myogenic niche. After one week of differentiation, we observed isolated, twitching myotubes followed by spontaneous contractions of the entire tissue-engineered muscle construct. In vitro engineered myofibers expressed canonical markers, ultrastructure and electrophysiological characteristics of skeletal muscle. Interestingly, after one-month engineered muscle constructs showed progressive degradation of the myofibers concomitant with fatty infiltration, paralleling the natural course of muscular degeneration. However, we do not yet know how dermis-resident precursor…

Inhibition of the myosin light chain kinase prevents hypoxia-induced blood-brain barrier disruption

2007

Increased mortality after stroke is associated with development of brain edema. The aim of the present study was to examine the contribution of endothelial myosin light chain (MLC) phosphorylation to hypoxia-induced blood-brain barrier (BBB) opening. Measurements of trans-endothelial electrical resistance (TEER) were performed to analyse BBB integrity in an in vitro co-culture model (bovine brain microvascular endothelial cells (BEC) and rat astrocytes). Brain fluid content was analysed in rats after stroke induction using a two-vein occlusion model. Dihydroethidium was used to monitor intracellular generation of reactive oxygen species (ROS) in BEC. MLC phosphorylation was detected using i…

Loss of Nrf2 in bone marrow-derived macrophages impairs antigen-driven CD8+ T cell function by limiting GSH and Cys availability

2015

NF-E2-related factor 2 (Nrf2), known to protect against reactive oxygen species, has recently been reported to resolve acute inflammatory responses in activated macrophages. Consequently, disruption of Nrf2 promotes a proinflammatory macrophage phenotype. In the current study, we addressed the impact of this macrophage phenotype on CD8(+) T cell activation by using an antigen-driven coculture model consisting of Nrf2(-/-) and Nrf2(+/+) bone marrow-derived macrophages (BMDMΦ) and transgenic OT-1 CD8(+) T cells. OT-1 CD8(+) T cells encode a T cell receptor that specifically recognizes MHC class I-presented ovalbumin OVA(257-264) peptide, thereby causing a downstream T cell activation. Interes…

Circulating cell-free DNA (cfDNA) and extracellular vesicles (EVs) as prognostic and predictive biomarkers in patients with advanced Non-Small Cell L…

2022

Intracellular glutathione in human hepatocytes incubated with S-adenosyl-L-methionine and GSH-depleting drugs

1991

Abstract The present study was undertaken to investigate (a) whether S- adenosyl- L -methionine (SAMe) added to culture medium can increase intracellular glutathione (GSH) levels in human hepatocytes and (b) whether SAMe can prevent the GSH depletion found in human hepatocytes incubated with GSH-depleting drugs (paracetamol, opiates, ethanol). Incubation of hepatocytes with increasing concentrations of SAMe resulted in a dose-dependent elevation of intracellular GSH content, which reached its maximum (35% increase) at 30 μM after 20 h. SAMe, as the only sulfur source in the medium, was efficient in repleting GSH-depleted hepatocytes following treatment with diethyl maleate. Incubation of hu…