Search results for " STRESS"
showing 10 items of 3936 documents
Aerobic growth of Rhodococcus aetherivorans BCP1 using selected naphthenic acids as the sole carbon and energy sources
2018
Naphthenic acids (NAs) are an important group of toxic organic compounds naturally occurring in hydrocarbon deposits. This work shows that Rhodococcus aetherivorans BCP1 cells not only utilize a mixture of eight different NAs (8XNAs) for growth but they are also capable of marked degradation of two model NAs, cyclohexanecarboxylic acid (CHCA) and cyclopentanecarboxylic acid (CPCA) when supplied at concentrations from 50 to 500 mgL−1 . The growth curves of BCP1 on 8XNAs, CHCA, and CPCA showed an initial lag phase not present in growth on glucose, which presumably was related to the toxic effects of NAs on the cell membrane permeability. BCP1 cell adaptation responses that allowed survi…
Probiotic yeast Kluyveromyces marxianus CIDCA 8154 shows anti-inflammatory and anti-oxidative stress properties in in vivo models.
2015
Inflammatory bowel diseases (IBDs) are complex affections with increasing incidence worldwide. Multiple factors are involved in the development and maintenance of the symptoms including enhanced oxidative stress in intestinal mucosa. The conventional therapeutic approaches for IBDs are based on the use anti-inflammatory drugs with important collateral effects and partial efficacy. In the present work we tested the anti-inflammatory capacity of Kluyveromyces marxianus CIDCA 8154 in different models. In vitro, we showed that the pretreatment of epithelial cells with the yeast reduce the levels of intracellular reactive oxygen species. Furthermore, in a murine model of trinitro benzene sulfon…
The purine analogues abacavir and didanosine increase acetaminophen-induced hepatotoxicity by enhancing mitochondrial dysfunction
2016
Background NRTIs are essential components of HIV therapy with well-documented, long-term mitochondrial toxicity in hepatic cells, but whose acute effects on mitochondria are unclear. As acetaminophen-induced hepatotoxicity also involves mitochondrial interference, we hypothesized that it would be exacerbated in the context of ART. Methods We evaluated the acute effects of clinically relevant concentrations of the most widely used NRTIs, alone or combined with acetaminophen, on mitochondrial function and cellular viability. Results The purine analogues abacavir and didanosine produced an immediate and concentration-dependent inhibition of oxygen consumption and complex I and III activity. Th…
New Genes Involved in Mild Stress Response Identified by Transposon Mutagenesis in Lactobacillus paracasei
2018
International audience; Lactic acid bacteria (LAB) are associated with various plant, animal, and human niches and are also present in many fermented foods and beverages. Thus, they are subjected to several stress conditions and have developed advanced response mechanisms to resist, adapt, and grow. This work aimed to identify the genes involved in some stress adaptation mechanisms in LAB. For this purpose, global reverse genetics was applied by screening a library of 1287 Lactobacillus paracasei transposon mutants for mild monofactorial stresses. This library was submitted independently to heat (52 degrees C, 30 min), ethanol (170 g.L-1, 30 min), salt (NaCl 0.8 M, 24 h), acid (pH 4.5, 24 h…
Cellular Responses in Human Dental Pulp Stem Cells Treated with Three Endodontic Materials
2017
Human dental pulp stem cells (HDPSCs) are of special relevance in future regenerative dental therapies. Characterizing cytotoxicity and genotoxicity produced by endodontic materials is required to evaluate the potential for regeneration of injured tissues in future strategies combining regenerative and root canal therapies. This study explores the cytotoxicity and genotoxicity mediated by oxidative stress of three endodontic materials that are widely used on HDPSCs: a mineral trioxide aggregate (MTA-Angelus white), an epoxy resin sealant (AH-Plus cement), and an MTA-based cement sealer (MTA-Fillapex). Cell viability and cell death rate were assessed by flow cytometry. Oxidative stress was m…
The mitochondrial antioxidant SS-31 increases SIRT1 levels and ameliorates inflammation, oxidative stress and leukocyte-endothelium interactions in t…
2018
AbstractThere is growing focus on mitochondrial impairment and cardiovascular diseases (CVD) in type 2 diabetes (T2D), and the development of novel therapeutic strategies in this context. It is unknown whether mitochondrial-targeting antioxidants such as SS-31 protect sufficiently against oxidative damage in diabetes. We aimed to evaluate if SS-31 modulates SIRT1 levels and ameliorates leukocyte-endothelium interactions, oxidative stress and inflammation in T2D patients. Anthropometric and metabolic parameters were studied in 51 T2D patients and 57 controls. Production of mitochondrial reactive oxygen species (ROS), mitochondrial membrane potential, glutathione content, leukocyte-endotheliu…
The mitochondria-targeted antioxidant MitoQ modulates oxidative stress, inflammation and leukocyte-endothelium interactions in leukocytes isolated fr…
2016
It is not known if the mitochondria-targeted antioxidants such as mitoquinone (MitoQ) can modulate oxidative stress and leukocyte-endothelium interactions in T2D patients. We aimed to evaluate the beneficial effect of MitoQ on oxidative stress parameters and leukocyte-endothelium interactions in leukocytes of T2D patients. The study population consisted of 98 T2D patients and 71 control subjects. We assessed metabolic and anthropometric parameters, mitochondrial reactive oxygen species (ROS) production, glutathione peroxidase 1 (GPX-1), NFκB-p65, TNFα and leukocyte-endothelium interactions. Diabetic patients exhibited higher weight, BMI, waist circumference, SBP, DBP, glucose, insulin, HOMA…
Does Metformin Protect Diabetic Patients from Oxidative Stress and Leukocyte-Endothelium Interactions?
2017
Since metformin can exert beneficial vascular effects, we aimed at studying its effect on reactive oxygen species (ROS) production, antioxidant enzyme expression, levels of adhesion molecules, and leukocyte-endothelium interactions in the leukocytes from type 2 diabetic (T2D) patients. The study was carried out in 72 T2D patients (41 of whom were treated with metformin for at least 12 months at a dose of 1700 mg per day), and in 40 sex- and age-matched control subjects. Leukocytes from T2D patients exhibited enhanced levels of mitochondrial ROS and decreased mRNA levels of glutathione peroxidase 1 (gpx1) and sirtuin 3 (sirt3) with respect to controls, whereas metformin was shown to revert t…
Insulin Resistance in PCOS Patients Enhances Oxidative Stress and Leukocyte Adhesion: Role of Myeloperoxidase
2016
Cardiovascular diseases and oxidative stress are related to polycystic ovary syndrome (PCOS) and insulin resistance (IR). We have evaluated the relationship between myeloperoxidase (MPO) and leukocyte activation in PCOS patients according to homeostatic model assessment of IR (HOMA-IR), and have explored a possible correlation between these factors and endocrine and inflammatory parameters. This was a prospective controlled study conducted in an academic medical center. The study population consisted of 101 PCOS subjects and 105 control subjects. We divided PCOS subjects into PCOS non-IR (HOMA-IR2.5). Metabolic and anthropometric parameters, total and mitochondrial reactive oxygen species (…
Sng1 associates with Nce102 to regulate the yeast Pkh–Ypk signalling module in response to sphingolipid status
2016
International audience; All cells are delimited by biological membranes, which are consequently a primary target of stress-induced damage. Cold alters membrane functionality by decreasing lipid fluidity and the activity of membrane proteins. In Saccharomyces cerevisiae, evidence links sphingolipid homeostasis and membrane phospholipid asymmetry to the activity of the Ypk1/2 proteins, the yeast orthologous of the mammalian SGK1-3 kinases. Their regulation is mediated by different protein kinases, including the PDK1 orthologous Pkh1/2p, and requires the function of protein effectors, among them Nce102p, a component of the sphingolipid sensor machinery. Nevertheless, the mechanisms and the act…