Search results for "Reactive"
showing 10 items of 1469 documents
Oxidative stress resistance in hippocampal cells is associated with altered membrane fluidity and enhanced nonamyloidogenic cleavage of endogenous am…
2010
Reactive oxygen species (ROS) have important roles as signaling molecules in the regulation of a variety of biological processes. On the other hand, chronic oxidative stress exerted by ROS is widely considered a causative factor in aging. Therefore, cells need to be able to adapt to a chronic oxidative challenge and do so to a certain cell-type-specific extent. Recently, we have shown in oxidative-stress-resistant cell lines, HT22(H2O2) and HT22(Glu), derived from the neuronal cell line HT22 by chronic exposure to sublethal concentrations of H(2)O(2) and glutamate, that, in addition to the known antioxidant defense mechanisms, e.g., activation of antioxidant enzymes or up-regulation of heat…
New neuroprotective effect of lemon integropectin on neuronal cellular model
2021
Lemon IntegroPectin obtained via hydrodynamic cavitation of organic lemon processing waste in water shows significant neuroprotective activity in vitro, as first reported in this study investigating the effects of both lemon IntegroPectin and commercial citrus pectin on cell viability, cell morphology, reactive oxygen species (ROS) production, and mitochondria perturbation induced by treatment of neuronal SH-SY5Y human cells with H2O2. Mediated by ROS, including H2O2 and its derivatives, oxidative stress alters numerous cellular processes, such as mitochondrial regulation and cell signaling, propagating cellular injury that leads to incurable neurodegenerative diseases. These results, and t…
Interplay of oxidants and antioxidants during exercise: Implications for muscle health
2010
Muscle contraction results in generation of reactive oxygen and nitrogen species (RONS) at a rate determined by the intensity, frequency, and duration of the exercise protocols. Strenuous exercise causes oxidation of protein, lipid, and DNA, release of cytosolic enzymes, and other signs of cell damage; however, only exhaustive exercise is detrimental. Indeed, the regulation of vascular tone, the excitation-contraction coupling, growth, and differentiation in skeletal muscle, are governed in part by RONS. This is accomplished by RONS interaction with redox-sensitive transcription factors, leading to increased gene expression of antioxidant enzymes, cytoprotective proteins, and other enzymes …
Studying the Neurovascular Unit: An Improved Blood–Brain Barrier Model
2009
The blood–brain barrier (BBB) closely interacts with the neuronal parenchyma in vivo. To replicate this interdependence in vitro, we established a murine coculture model composed of brain endothelial cell (BEC) monolayers with cortical organotypic slice cultures. The morphology of cell types, expression of tight junctions, formation of reactive oxygen species, caspase-3 activity in BECs, and alterations of electrical resistance under physiologic and pathophysiological conditions were investigated. This new BBB model allows the application of techniques such as laser scanning confocal microscopy, immunohistochemistry, fluorescent live cell imaging, and electrical cell substrate impedance se…
Oligodendrocyte Precursor Cells Synthesize Neuromodulatory Factors
2015
NG2 protein-expressing oligodendrocyte progenitor cells (OPC) are a persisting and major glial cell population in the adult mammalian brain. Direct synaptic innervation of OPC by neurons throughout the brain together with their ability to sense neuronal network activity raises the question of additional physiological roles of OPC, supplementary to generating myelinating oligodendrocytes. In this study we investigated whether OPC express neuromodulatory factors, typically synthesized by other CNS cell types. Our results show that OPC express two well-characterized neuromodulatory proteins: Prostaglandin D2 synthase (PTGDS) and neuronal Pentraxin 2 (Nptx2/Narp). Expression levels of the enzym…
Cell-Free Coelomic Fluid Extracts of the Sea Urchin Arbacia lixula Impair Mitochondrial Potential and Cell Cycle Distribution and Stimulate Reactive …
2020
Triple-negative breast cancer (TNBC) is a highly malignant tumor histotype which lacks effective targeted therapies, thereby being considered as the most aggressive form of breast carcinoma. To identify novel compounds which could counteract TNBC cell growth, we explored the in vitro effects of crude extracts and <
Endoplasmic reticulum stress is involved in response of human laryngeal carcinoma cells to carboplatin but is absent in carboplatin resistant cells
2013
The major obstacle of successful tumor treatment with carboplatin (CBP) is the development of drug resistance. In the present study, we found that following treatment with CBP the amount of platinum which enters the human laryngeal carcinoma (HEp2)-derived CBP- resistant (7T) cells is reduced relative to the parental HEp2. As a consequence, the formation of reactive oxidative species (ROS) is reduced, the induction of endoplasmic reticulum (ER) stress is diminished, the amount of inter- and intrastrand cross-links is lower, and the induction of apoptosis is depressed. In HEp2 cells, ROS scavenger tempol, inhibitor of ER stress salubrinal, as well as gene silencing of ER stress marker CCAAT/…
Pyrrolo[2',3':3,4]cyclohepta[1,2-d][1,2]oxazoles, a New Class of Antimitotic Agents Active against Multiple Malignant Cell Types
2020
A new class of pyrrolo[2',3':3,4]cyclohepta[1,2-d][1,2]oxazoles was synthesized for the treatment of hyperproliferative pathologies, including neoplasms. The new compounds were screened in the 60 human cancer cell lines of the NCI drug screen and showed potent activity with GI50 values reaching the nanomolar level, with mean graph midpoints of 0.08-0.41 μM. All compounds were further tested on six lymphoma cell lines, and eight showed potent growth inhibitory effects with IC50 values lower than 500 nM. Mechanism of action studies showed the ability of the new [1,2]oxazoles to arrest cells in the G2/M phase in a concentration dependent manner and to induce apoptosis through the mitochondrial…
Monocyte-derived dendritic cells of patients with coronary artery disease show an increased expression of costimulatory molecules CD40, CD80 and CD86…
2007
Background Atherosclerosis is a disease triggered by diverse exogenous stimuli and sustained by chronic inflammatory processes. Dendritic cells (DCs) are key regulatory antigen-presenting cells and play a crucial role in regulating the adaptive and innate immune system in any chronic inflammatory process. DCs are present in atherosclerotic lesions in the areas of the highest T-cell density. So far, their role in atherosclerosis has not been fully elucidated. We investigated the phenotypic properties of DCs in patients with coronary artery disease (CAD) in comparison to healthy individuals. Methods Peripheral blood monocytes were isolated from 50 patients with CAD and 19 healthy individuals …
Hypothalamic S-Nitrosylation Contributes to the Counter-Regulatory Response Impairment following Recurrent Hypoglycemia
2013
http://www.ncbi.nlm.nih.gov/pubmed/23894333; International audience; AIMS: Hypoglycemia is a severe side effect of intensive insulin therapy. Recurrent hypoglycemia (RH) impairs the counter-regulatory response (CRR) which restores euglycemia. During hypoglycemia, ventromedial hypothalamus (VMH) production of nitric oxide (NO) and activation of its receptor soluble guanylyl cyclase (sGC) are critical for the CRR. Hypoglycemia also increases brain reactive oxygen species (ROS) production. NO production in the presence of ROS causes protein S-nitrosylation. S-nitrosylation of sGC impairs its function and induces desensitization to NO. We hypothesized that during hypoglycemia, the interaction b…