Search results for " senes"
showing 10 items of 146 documents
Carbocysteine counteracts the effects of cigarette smoke on cell growth and on the SIRT1/FoxO3 axis in bronchial epithelial cells
2016
Abstract Background Cigarette smoke may accelerate cellular senescence by increasing oxidative stress. Altered proliferation and altered expression of anti-aging factors, including SIRT1 and FoxO3, characterise cellular senescence. The effects of carbocysteine on the SIRT1/FoxO3 axis and on downstream molecular mechanisms in human bronchial epithelial cells exposed to cigarette smoke are largely unknown. Aims Aim of this study was to explore whether carbocysteine modulated SIRT1/FoxO3 axis, and downstream molecular mechanisms associated to cellular senescence, in a bronchial epithelial cell line (16-HBE) exposed to cigarette smoke. Methods 16HBE cells were stimulated with/without cigarette …
Foliar influences on the vegetative development of grapevine
1997
<p style="text-align: justify;">Various defoliation treatments were applied to grapevine shoots during the whole duration of the growth period: full defoliation of every shoot of vine, defoliations retaining a various number of adult leaves to the base of every shoot and defoliations retaining a various number of young leaves to the top. The effects of these treatments allow to identify the major foliar influences on the vegetative development. Total defoliation induced a lesser intemodal elongation. This result is probably due, in part, to a carbohydrates deficiency consecutive to this drastic treatment. The defoliations with variation of the number of young leaves showed that the le…
Down-regulation of nuclear binding activities of OXBOX-REBOX transcription factors during cellular senescence.
1996
Functional capacity of mitochondria declines during aging and this impairment may have a major role in aging process. Several observations indicate that transcriptional efficiency is reduced during aging. Our purpose was to find out whether aging and cellular senescence affect the nuclear binding activities of transcription factors which bind to OXBOX-REBOX sequence present in promoter regions of numerous nuclear genes encoding mitochondrial proteins. These factors regulate and coordinate the expression of mitochondrial proteins. We observed a strong down-regulation in the nuclear binding activities of OXBOX-REBOX factors in replicatively senesced human WI-38 and IMR-90 fibroblasts. On the …
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…
p53 as the main traffic controller of the cell signaling network
2010
Among different pathological conditions that affect human beings, cancer has received a great deal of attention primarily because it leads to significant morbidity and mortality. This is essentially due to increasing world-wide incidence of this disease and the inability to discover the cause and molecular mechanisms by which normal human cells acquire the characteristics that define cancer cells. Since the discovery of p53 over a quarter of a century ago, it is now recognized that virtually all cell fate pathways of live cells and the decision to die are under the control of p53. Such extensive involvement indicates that p53 protein is acting as a major traffic controller in the cell signa…
Water-Soluble Chlorophyll Protein (WSCP) Stably Binds Two or Four Chlorophylls
2017
Water-soluble chlorophyll proteins (WSCPs) of class IIa from Brassicaceae form tetrameric complexes containing one chlorophyll (Chl) per apoprotein but no carotenoids. The complexes are remarkably stable toward dissociation and protein denaturation even at 100 °C and extreme pH values, and the Chls are partially protected against photooxidation. There are several hypotheses that explain the biological role of WSCPs, one of them proposing that they function as a scavenger of Chls set free upon plant senescence or pathogen attack. The biochemical properties of WSCP described in this paper are consistent with the protein acting as an efficient and flexible Chl scavenger. At limiting Chl concen…
Decreased response to acetylcholine during aging of Aplysia neuron R15
2013
How aging affects the communication between neurons is poorly understood. To address this question, we have studied the electrophysiological properties of identified neuron R15 of the marine mollusk Aplysia californica . R15 is a bursting neuron in the abdominal ganglia of the central nervous system and is implicated in reproduction, water balance, and heart function. Exposure to acetylcholine (ACh) causes an increase in R15 burst firing. Whole-cell recordings of R15 in the intact ganglia dissected from mature and old Aplysia showed specific changes in burst firing and properties of action potentials induced by ACh. We found that while there were no significant changes in resting membrane p…
Benzo[a]pyrene represses DNA repair through altered E2F1/E2F4 function marking an early event in DNA damage-induced cellular senescence
2020
AbstractTranscriptional regulation of DNA repair is of outmost importance for the restoration of DNA integrity upon genotoxic stress. Here we report that the potent environmental carcinogen benzo[a]pyrene (B[a]P) activates a cellular DNA damage response resulting in transcriptional repression of mismatch repair (MMR) genes (MSH2, MSH6, EXO1) and of RAD51, the central homologous recombination repair (HR) component, ultimately leading to downregulation of MMR and HR. B[a]P-induced gene repression is caused by abrogated E2F1 signalling. This occurs through proteasomal degradation of E2F1 in G2-arrested cells and downregulation of E2F1 mRNA expression in G1-arrested cells. Repression of E2F1-me…
Estudio de la transformación fibroblasto-miofibroblasto, la senescencia y el metabolismo de fibroblastos aislados de pacientes con fibrosis pulmonar …
2021
La Fibrosis Pulmonar idiopática (FPI) está definida como una neumonía intersticial fibrosante crónica de causa desconocida, progresiva y fatal que afecta fundamentalmente a adultos mayores de 60 años, limitada a los pulmones y asociada con el patrón histopatológico de neumonía intersticial usual (NIU). La ausencia de manifestaciones específicas de la FPI supone un obstáculo para su detección temprana. Es una enfermedad de diagnóstico difícil y tardío, con un abordaje terapéutico de eficacia reducida. Estas características suscitan la necesidad de encontrar nuevos biomarcadores asociados a la fibrosis y nuevas dianas terapéuticas para un diagnóstico temprano e incrementar la calidad y espera…
Sponges (Porifera) model systems to study the shift from immortal to senescent somatic cells: the telomerase activity in somatic cells.
1998
Abstract Sponges (Porifera) represent the lowest metazoan phylum, characterized by a pronounced plasticity in the determination of cell lineages. In a first approach to elucidate the molecular mechanisms controlling the switch from the cell lineage with a putative indefinite growth capacity to senescent, somatic cells, the activity of the telomerase as an indicator for immortality has been determined. The studies were performed with the marine demosponges Suberites domuncula and Geodia cydonium . It was found that the activity for the telomerase in the tissue of both sponges is high; a quantitative analysis revealed that the extract from S. domuncula contained 10.3 TPG units per 5000 cell e…