Search results for "guanosine"
showing 10 items of 171 documents
Visual Working Memory Requires Permissive and Instructive NO/cGMP Signaling at Presynapses in the Drosophila Central Brain.
2017
The gaseous second messenger nitric oxide (NO) has been shown to regulate memory formation by activating retrograde signaling cascades from post- to presynapse that involve cyclic guanosine monophosphate (cGMP) production to induce synaptic plasticity and transcriptional changes. In this study, we analyzed the role of NO in the formation of a visual working memory that lasts only a few seconds. This memory is encoded in a subset of ring neurons that form the ellipsoid body in the Drosophila brain. Using genetic and pharmacological manipulations, we show that NO signaling is required for cGMP-mediated CREB activation, leading to the expression of competence factors like the synaptic homer pr…
Nitric Oxide System and Bronchial Epithelium: More Than a Barrier
2021
Airway epithelium forms a physical barrier that protects the lung from the entrance of inhaled allergens, irritants, or microorganisms. This epithelial structure is maintained by tight junctions, adherens junctions and desmosomes that prevent the diffusion of soluble mediators or proteins between apical and basolateral cell surfaces. This apical junctional complex also participates in several signaling pathways involved in gene expression, cell proliferation and cell differentiation. In addition, the airway epithelium can produce chemokines and cytokines that trigger the activation of the immune response. Disruption of this complex by some inflammatory, profibrotic, and carcinogens agents c…
Uncoupling of dynamin polymerization and GTPase activity revealed by the conformation-specific nanobody dynab
2017
Dynamin is a large GTPase that forms a helical collar at the neck of endocytic pits, and catalyzes membrane fission (Schmid and Frolov, 2011; Ferguson and De Camilli, 2012). Dynamin fission reaction is strictly dependent on GTP hydrolysis, but how fission is mediated is still debated (Antonny et al., 2016): GTP energy could be spent in membrane constriction required for fission, or in disassembly of the dynamin polymer to trigger fission. To follow dynamin GTP hydrolysis at endocytic pits, we generated a conformation-specific nanobody called dynab, that binds preferentially to the GTP hydrolytic state of dynamin-1. Dynab allowed us to follow the GTPase activity of dynamin-1 in real-time. We…
Oxidative Stress in Non-Dialysis-Dependent Chronic Kidney Disease Patients
2021
Background: Cardiovascular complications are the leading cause of morbidity and mortality at any stage of chronic kidney disease (CKD). Moreover, the high rate of cardiovascular mortality observed in these patients is associated with an accelerated atherosclerosis process that likely starts at the early stages of CKD. Thus, traditional and non-traditional or uremic-related factors represent a link between CKD and cardiovascular risk. Among non-conventional risk factors, particular focus has been placed on anaemia, mineral and bone disorders, inflammation, malnutrition and oxidative stress and, in this regard, connections have been reported between oxidative stress and cardiovascular disease…
Studies to Elucidate the Mechanism of Cardio Protective and Hypotensive Activities of Anogeissus acuminata (Roxb. ex DC.) in Rodents
2020
Anogeissus acuminata (Roxb. ex DC.) is a folkloric medicinal plant in Asia
Structural analysis of Cu(II) ligation to the 5'-GMP nucleotide by pulse EPR spectroscopy.
2007
JBIC Journal of Biological Inorganic Chemistry, 12 (6)
Interaction of Novel Metal Complexes with DNA: Synthetic and Structural Aspects
2009
Metal ions bind to nucleic acids at various positions. This binding can be modulated by using metal complexes with appropriate ligands. Novel mono- and especially dinuclear metal complexes could be a powerful tool to detect rare, but still physiologically relevant, forms of DNA, e.g. the left-handed Z-DNA. In this review, our recent research activities in this area of bioinorganic chemistry are summarized. A special emphasis is laid on the synthetic challenges that arose upon the synthesis of the polyamine ligands. Further, some rather unusual approaches to elucidate the solution structure of copper bound to guanosine monophosphate with the help of pulsed EPR techniques like ENDOR and HYSC…
Early ROS-mediated DNA damage and oxidative stress biomarkers in Monoclonal B Lymphocytosis
2012
Monoclonal B Lymphocytosis (MBL) is defined as asymptomatic monoclonal B-cell expansion characterised by a CLL-phenotype, but with less than 5 x 10(9)/I circulating cells. Reactive oxygen species (ROS)-mediated cell damage plays a critical role in the initiation of carcinogenesis as well as in malignant transformation. The goal of this study was to perform an analysis of the oxidative stress statuses of patients affected by MBL and chronic lymphocytic leukaemia (CLL). We examined peripheral blood and urine specimens from 29 patients with MBL, 55 with CLL and 31 healthy subjects. There was a significant increase in the occurrence of the mutagenic base 8-oxo-2'-deoxiguanosine (8-oxo-dG) in th…
Machine learning of reverse transcription signatures of variegated polymerases allows mapping and discrimination of methylated purines in limited tra…
2020
AbstractReverse transcription (RT) of RNA templates containing RNA modifications leads to synthesis of cDNA containing information on the modification in the form of misincorporation, arrest, or nucleotide skipping events. A compilation of such events from multiple cDNAs represents an RT-signature that is typical for a given modification, but, as we show here, depends also on the reverse transcriptase enzyme. A comparison of 13 different enzymes revealed a range of RT-signatures, with individual enzymes exhibiting average arrest rates between 20 and 75%, as well as average misincorporation rates between 30 and 75% in the read-through cDNA. Using RT-signatures from individual enzymes to trai…
Impairment of antioxidant enzymes, lipid peroxidation and 8-oxo-2'-deoxyguanosine in advanced epithelial ovarian carcinoma of a Spanish community.
2006
In the present study, we describe the changes of antioxidant enzyme activities and other oxidative stress-related parameters in a mediterranean cohort of women affected with epithelial ovarian carcinoma (EOC). For that purpose, the most representative enzymatic activities, such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) and the oxidized/reduced glutathione (GSSG/GSH) ratio have been analyzed in tumor tissue biopsies and compared with the normal tissue of the same patient. As oxidation products, the levels of malondialdehyde (MDA) as an indication of lipid peroxidation, and the DNA damaged base 8-oxo-2'-deoxyguanosine (8-oxo-dG) have been also measured. Ad…