Search results for "STRESS"
showing 10 items of 6278 documents
FRI0014 Antioxidant role of microvesicles from adipose tissue-derived mesenchymal stem cells in human osteoarthritic chondrocytes
2017
Background Oxidative stress results in the disruption of normal physiologic signaling leading to inflammatory changes, cartilage degradation and osteoarthritis (OA) progression (1). Recent advances have revealed the role of cell-derived microvesicles (MV) as a new mechanism of cell-to-cell communication with potential therapeutic applications. We have shown previously the antiinflammatory effects of human adipose tissue-derived mesenchymal stem cells (AD-MSC) conditioned medium in OA chondrocytes (2). Objectives We have isolated the MV fraction from the secretome of AD-MSC to investigate its activity on oxidative stress and inflammation in OA chondrocytes stimulated with interleukin (IL)-1β…
Effect of oxidant stressors and phenolic antioxidants on the ochratoxigenic fungusAspergillus carbonarius
2015
BACKGROUND There are few studies dealing with the relationship between oxidative stress and ochratoxin A (OTA) biosynthesis. In this work, we analyzed the effect of the oxidant stressor menadione and the antioxidants 3,5-di-tert-butyl-4-hydroxytoluene (BHT), catechin, resveratrol and a polyphenolic extract on growth, generation of reactive oxygen species (ROS), OTA production and gene expression of antioxidant enzymes of Aspergillus carbonarius. RESULTS Exposure to menadione concentrations higher than 20 µmol L−1 led to increases in ROS and OTA levels and a decrease in growth rate. Exposure to 2.5–10 mmol L−1 BHT also led to higher ROS and OTA levels, although growth rate was only affected …
Cytomics of Oxidative Stress: Probes and Problems
2017
Oxidative stress has been implicated in cellular senescence and aging, as well as in the onset and progression of many diverse genetic and acquired diseases and conditions. However, reactive oxygen (ROS) and nitrogen (RNS) species initiating oxidative stress also serve important regulatory roles, mediated by intercellular and intracellular signaling, adaptation to endogenous and exogenous stress, and destruction of invading pathogens. Fluorescence-based analysis of oxidative stress and related processes is an important cytomic application; almost 4000 papers were published between 1989 and 2016. To ascertain the specific role of ROS and RNS in oxidative stress studies by cytomic methodologi…
Neuroprotection and antioxidative effects of Sijunzi Tang Decoction in the nematode Caenorhabditis elegans
2016
Abstract Introduction Knowledge about the pharmacological properties of traditional TCM formulas is scarce as is their impact on aging. This study evaluated the potential effects of Sijunzi Tang Decoction (SJZTD), Si-Wu-Tang Decoction (SWTD), and Liuwei Dihuang Decoction (LWDHD) against oxidative stress and glucotoxic stress-induced neuronal dysfunction and lifespan reduction. Methods Nematodes ( C. elegans ) were cultivated under 10 mmol/L paraquat or 400 mmol/L glucose to assess the protective effects of a systemic Traditional Chinese Medicine (TCM) treatment. Lifespan was determined by calculation of Kaplan-Meier survival curves, formation of reactive oxygen species was quantified by hyd…
Redox Regulation by HGF/c-Met in Liver Disease
2017
Reactive oxygen species (ROS) have gained considerable attention in recent years because of their direct involvement in the regulation of multiple physiological and pathological processes. Under normal conditions, ROS have an important role in cell signaling and function as essential mediators of cell homeostasis. However, imbalance between ROS and antioxidant systems induces oxidative stress, which leads to cell and tissue damage. The cellular redox modulation by hepatocyte growth factor (HGF) and its receptor c-Met in the liver has been studied extensively in the past. The generation of liver-specific c-Met–knockout mice has allowed to demonstrate the fundamental importance of HGF/c-Met i…
Dimethyl fumarate alters intracellular Ca2+ handling in immune cells by redox-mediated pleiotropic effects
2019
Dimethyl fumarate (DMF) is widely used to treat the human autoimmune diseases multiple sclerosis (MS) and psoriasis. DMF causes short-term oxidative stress and activates the antioxidant response via the transcription factor Nrf2 but its immunosuppressive effect is not well understood. Immune cell activation depends on calcium signaling which itself is influenced by the cellular redox state. We therefore measured calcium, reactive oxygen species levels and glutathione content in lymphocytes from immunized mice before onset of experimental autoimmune encephalomyelitis, in peripheral blood mononuclear cells from MS patients treated with DMF, and in mouse splenocytes treated ex vivo with DMF. T…
Impact of Oxidative Stress on the Heart and Vasculature
2017
Abstract Vascular disease and heart failure impart an enormous burden in terms of global morbidity and mortality. Although there are many different causes of cardiac and vascular disease, most causes share an important pathological mechanism: oxidative stress. In the failing heart, oxidative stress occurs in the myocardium and correlates with left ventricular dysfunction. Reactive oxygen species (ROS) negatively affect myocardial calcium handling, cause arrhythmia, and contribute to cardiac remodeling by inducing hypertrophic signaling, apoptosis, and necrosis. Similarly, oxidative balance in the vasculature is tightly regulated by a wealth of pro- and antioxidant systems that orchestrate r…
The role of Ca(2+) in cell death caused by oxidative glutamate toxicity and ferroptosis
2018
Ca(2+) ions play a fundamental role in cell death mediated by oxidative glutamate toxicity or oxytosis, a form of programmed cell death similar and possibly identical to other forms of cell death like ferroptosis. Ca(2+) influx from the extracellular space occurs late in a cascade characterized by depletion of the intracellular antioxidant glutathione, increases in cytosolic reactive oxygen species and mitochondrial dysfunction. Here, we aim to compare oxidative glutamate toxicity with ferroptosis, address the signaling pathways that culminate in Ca(2+) influx and cell death and discuss the proteins that mediate this. Recent evidence hints toward a role of the machinery responsible for stor…
Evaluation of Carotenoids Protection Against Oxidative Stress in the Animal Model Caenorhabditis elegans
2019
The nematode Caenorhabditis elegans is a versatile and powerful model organism for animal experimental research and, despite being an invertebrate, displays remarkably similar molecular bases and conserved cellular pathways to those of humans. Oxidative stress is an etiological factor that influences numerous diseases, degenerative processes and aging. C. elegans has revealed as an opportune and feasible organism to investigate the antioxidant effects of different bioactives or complex food matrices, and a number of protocols have been developed by using different oxidative stressors. Carotenoids are recognized as quenchers and scavengers of reactive oxygen species, and many of their relate…
Erwinia amylovoracatalases KatA and KatG are virulence factors and delay the starvation-induced viable but non-culturable (VBNC) response
2017
The life cycle of the plant pathogen Erwinia amylovora comprises periods inside and outside the host in which it faces oxidative stress caused by hydrogen peroxide (H2 O2 ) and other compounds. The sources of this stress are plant defences, other microorganisms and/or exposure to starvation or other environmental challenges. However, the functional roles of H2 O2 -neutralizing enzymes, such as catalases, during plant-pathogen interactions and/or under starvation conditions in phytopathogens of the family Erwiniaceae or closely related families have not yet been investigated. In this work, the contribution of E. amylovora catalases KatA and KatG to virulence and survival in non-host environm…