Search results for "Acellular"
showing 10 items of 1986 documents
The impact of dehydration rate on the production and cellular location of reactive oxygen species in an aquatic moss.
2012
† Background and Aims The aquatic moss Fontinalis antipyretica requires a slow rate of dehydration to survive a desiccation event. The present work examined whether differences in the dehydration rate resulted in corresponding differences in the production of reactive oxygen species (ROS) and therefore in the amount of cell damage. † Methods Intracellular ROS production by the aquatic moss was assessed with confocal laser microscopy and the ROS-specific chemical probe 2,7-dichlorodihydrofluorescein diacetate. The production of hydrogen peroxide was also quantified and its cellular location was assessed. † Key Results The rehydration of slowly dried cells was associated with lower ROS produc…
ATR-FTIR spectroscopy for the routine quality control of exosome isolations
2021
Abstract Exosomes are nanosized vesicles containing specific cargos of DNA, RNA, proteins, metabolites, and intracellular and membrane lipids. Exosome isolation needs to be optimized carefully depending on the type of biofluid and tissue and the retrieved exosomes need to be characterized. The main objective of this study was to determine the feasibility of a multimodal analysis of Attenuated Total Reflectance – Fourier Transform Infrared (ATR-FTIR) spectroscopy and UPLC–QqTOF-MSMS for the development of a routine quality control tool of isolated exosomes and the rapid characterization of their lipid profiles and total protein content. Using human milk as model example, exosomes were isolat…
Isolation and characterization of Wnt pathway-related genes from Porifera.
2006
The Wnt signal acts by binding to Frizzled receptors, with the subsequent activation of two different signal transduction cascades, the canonical and the non-canonical Wnt pathways, involved in cell growth, differentiation, migration and fate. The canonical pathway functions through the translocation of beta-catenin to the nucleus and the activation of TCF/LEF transcription factors; it plays an important role in developmental patterning and cell fate decisions during embryogenesis. The non-canonical Wnt pathway is responsible for the planar cell polarity process in invertebrates, and for the convergent-extension movements during vertebrate gastrulation. The final effect of the non-canonical…
Cell Wall and Secreted Proteins ofCandida albicans: Identification, Function, and Expression
1998
SUMMARYThe cell wall is essential to nearly every aspect of the biology and pathogenicity of Candida albicans. Although it was intially considered an almost inert cellular structure that protected the protoplast against osmotic offense, more recent studies have demonstrated that it is a dynamic organelle. The major components of the cell wall are glucan and chitin, which are associated with structural rigidity, and mannoproteins. The protein component, including both mannoprotein and nonmannoproteins, comprises some 40 or more moieties. Wall proteins may differ in their expression, secretion, or topological location within the wall structure. Proteins may be modified by glycosylation (prima…
Some biological features of Candida albicans mutants for genes coding fungal proteins containing the CFEM domain
2011
Several biological features of Candida albicans genes (PGA10, RBT5 and CSA1) coding for putative polypeptide species belonging to a subset of fungal proteins containing an eight-cysteine domain referred as common in several fungal extracellular membrane (CFEM) are described. The deletion of these genes resulted in a cascade of pleiotropic effects. Thus, mutant strains exhibited higher cell surface hydrophobicity levels and an increased ability to bind to inert or biological substrates. Confocal scanning laser microscopy using concanavalin A-Alexafluor 488 (which binds to mannose and glucose residues) and FUN-1 (a cytoplasmic fluorescent probe for cell viability) dyes showed that mutant stra…
Isolation and characterization of extracellular vesicles in Candida albicans
2020
Background : The occurrence of systemic infections due to C. albicans has increased especially in critically ill patients. In fungal infections, secretory mechanisms are key events for disease establishment. Recent findings demonstrate that fungal organisms release many molecular components to the extracellular space in extracellular vesicles. Aims: We develop a method to obtain exosomes from yeast cultures of the Candida albicans . Methods : Yeast strains used in this work were C. albicans SC5314, C. parapsilosis (ATCC 22019) and C. krusei (ATCC 6258). Yeasts were grown at 37.º in liquid YPD medium. The cell cultures were centrifuged and the supernatant filtered through sterile nitrocellul…
As2O3-induced oxidative stress and cycle progression in a human intestinal epithelial cell line (Caco-2)
2007
Foods and drinking water are the main routes for human exposure to inorganic arsenic, the intestinal epithelium being the first barrier against such exogenous toxicants. The present study evaluates the effect of As(III) (0.5-25 microM) upon Caco-2 cells as an intestinal epithelia model. Cell viability, intracellular formation of reactive oxygen species (ROS), mitochondrial membrane potential (Deltapsim) changes, and cell cycle distribution in exposed cultures were evaluated. The intracellular production of ROS was seen to increase in a non-dose dependent manner at all concentrations tested, with impairment of cell mitochondrial enzyme function secondary to a loss of Deltapsim. Concentration…
Melanoma cells release extracellular vesicles which contain H1° RNA and RNA-binding proteins
2015
G26/24 oligodendroglioma cells produce EVs that contain pro-apoptotic proteins, such as FasL and TRAIL, able to induce neuronal- [1] and astrocytic- [2] death. Cancer cells release EVs [3] through which transferring proteins, such as extracellular matrix remodelling proteases [4], and H1°, a differentiation-specific histone [5]. By releasing H1°, cells could escape differentiation cues [5]. To verify the role of EVs in releasing specific proteins and mRNAs, in this study we used A375 melanoma cells. EVs were purified from cell culture media as previously reported [1, 2]. T1 RNase-protection assays were performed on total cell lysates and EVs, as described elsewhere [6]. RNA-binding proteins…
Transporter-mediated replacement of extracellular glutamate for GABA in the developing murine neocortex
2013
During early development, cortical neurons migrate from their places of origin to their final destinations where they differentiate and establish synaptic connections. During corticogenesis, radially migrating cells move from deeper zone to the marginal zone, but they do not invade the latter. This "stop" function of the marginal zone is mediated by a number of factors, including glutamate and γ-aminobutyric acid (GABA), two main neurotransmitters in the central nervous system. In the marginal zone, GABA has been shown to be released via GABA transporters (GAT)-2/3, whereas glutamate transporters (EAATs) operate in the uptake mode. In this study, GABAergic postsynaptic currents (GPSCs) were…
Alteraciones de la neurotransmisión en hipocampo de ratas hiperamonémicas. papel de la neuroinflamación. modulación por GMPc extracelular
2021
La Encefalopatía Hepática (EH) es un síndrome neuropsiquiátrico complejo producido por un fallo hepático. Cuando el hígado falla se producen hiperamonemia (HA) e inflamación que actúan sinérgicamente produciendo neuroinflamación, lo que da lugar a alteraciones en la neurotransmisión y alteraciones cognitivas y motoras. Estudios anteriores del grupo han demostrado que el aumento de los niveles de GMPc extracelular disminuye la neuroinflamación y revierte las alteraciones cognitivas y motoras observadas en ratas hiperamonémicas. Sin embargo, los mecanismos responsables se desconocían. En la presente tesis doctoral hemos demostrado que la hiperamonemia crónica reduce la respuesta de los recept…