Search results for "programme"
showing 10 items of 874 documents
Induction of Apoptosis, Autophagy and Ferroptosis by Thymus vulgaris and Arctium lappa Extract in Leukemia and Multiple Myeloma Cell Lines
2020
Thymus vulgaris and Arctium lappa have been used as a folk remedy in the Iraqi Kurdistan region to deal with different health problems. The aim of the current study is to investigate the cytotoxicity of T. vulgaris and A. lappa in leukemia and multiple myeloma (MM) cell lines and determine the mode of cell death triggered by the most potent cytotoxic fractions of both plants in MM. Resazurin assay was used to evaluate cytotoxic and ferroptosis activity, apoptosis, and modulation in the cell cycle phase were investigated via Annexin V-FITC/PI dual stain and cell-cycle arrest assays. Furthermore, we used western blotting assay for the determination of autophagy cell death. n-Hexane, chlorofor…
The Role of Autophagy and Apoptosis During Embryo Development
2015
Programmed cell death (PCD) and cell survival are two sides of the same coin. Autopha‐ gy and apoptosis are crucial processes during embryo development of Invertebrates and Vertebrates organisms, as they are necessary for the formation of a new organism, start‐ ing from a fertilized egg. Fertilization triggers cell remodeling from each gamete to a toti‐ potent zygote. During embryogenesis, the cells undergo various processes, thus allowing the transformation of the embryo into an adult organism. In particular, cells require the appropriate tools to suddenly modify their morphology and protein content in order to respond to intrinsic and external stimuli. Autophagy and apoptosis are involved…
Studies on the fat body of oncopeltus fasciatus invaded by pseudomonas aeruginosa1
1977
A fatal disease in laboratory cultures of Oncopeltus fasciatus is caused by Pseudomonas aeruginosa , which invades the fat body and destroys it. The cellular breakdown was studied by electron microscopy. Infected fat body tissue shrinks, disintegrates, and dissolves. The nuclei, apparently, remain intact until immediately before cell death. Bacteria, which are found singularly in cytoplasm, form an expanding electron-lucent halo. Within this halo, free ribosomes and ribosomes of rough endoplasmic reticulum (ER) disappear. The changes are presumably caused by proteolytic activity of the parasite, which results in the destruction of the fat body and death of the host. Lipid droplets dissolve,…
Autophagy-Dependent Anticancer Immune Responses Induced by Chemotherapeutic Agents in Mice
2011
Antineoplastic chemotherapies are particularly efficient when they elicit immunogenic cell death, thus provoking an anticancer immune response. Here we demonstrate that autophagy, which is often disabled in cancer, is dispensable for chemotherapy-induced cell death but required for its immunogenicity. In response to chemotherapy, autophagy-competent, but not autophagy-deficient, cancers attracted dendritic cells and T lymphocytes into the tumor bed. Suppression of autophagy inhibited the release of adenosine triphosphate (ATP) from dying tumor cells. Conversely, inhibition of extracellular ATP-degrading enzymes increased pericellular ATP in autophagy-deficient tumors, reestablished the recr…
Assessment of Endoplasmic Reticulum Stress and the Unfolded Protein Response in Endothelial Cells
2011
In the vascular wall, the most inner cell layer that separates the blood from organelles is comprised of only a single layer of endothelial cells (ECs). This cell type is fundamental to a large variety of processes, ranging from blood coagulation and interaction with inflammatory cells to cardiovascular diseases such as hypertension, diabetes, and atherosclerosis. Dysfunction of ECs is often causally linked to these processes such that research exploring such events attracted much attention. Damage of ECs and subsequent disruption of the intact endothelial barrier can result not only from oxidative stress, but also from conditions that stress the endoplasmic reticulum (ER) and induce a sign…
Death of mitochondria during programmed cell death of leaf mesophyll cells
2005
The role of plant mitochondria in the programmed cell death (PCD) is widely discussed. However, spectrum and sequence of mitochondrial structural changes during different types of PCD in leaves are poorly described. Pea, cucumber and rye plants were grown under controlled growing conditions. A part of them were sprinkled with ethylene releaser to accelerate cell death. During yellowing the palisade parenchyma mitochondria were attracted to nuclear envelope. Mitochondrial matrix became electron translucent. Mitochondria entered vacuole by invagination of tonoplast and formed multivesicular bodies. Ethephon treatment increased the frequency of sticking of mitochondria to the nuclear envelope …
Caspase 3 Targeted Cargo Delivery in Apoptotic Cells Using Capped Mesoporous Silica Nanoparticles
2015
[EN] Excessive apoptotic cell death is at the origin of several pathologies, such as degenerative disorders, stroke or ischemia-reperfusion damage. In this context, strategies to improve inhibition of apoptosis and other types of cell death are of interest and may represent a pharmacological opportunity for the treatment of cell-death-related disorders. In this scenario new peptide-containing delivery systems (solids S1-P1and S1-P2) are described based on meso-porous silica nanoparticles (MSNs) loaded with a dye and capped with the KKGDEVDKKARDEVDK (P1) peptide that contains two repeats of the DEVD target sequence that are selectively hydrolyzed by caspase3 (C3). This enzyme plays a central…
How to Select a Mate: Kel1 is a Phosphorylation-Regulated Suppressor of the Pheromone Signaling Pathway
2021
Mechanisms have evolved that allow cells to detect signals and generate an appropriate response. The accuracy of these responses relies on the ability of cells to discriminate between signal and noise. How cells filter noise in signaling pathways is not well understood. We have analyzed noise suppression in the yeast pheromone signaling pathway. By combining synthetic genetic array screening, mass spectrometry and single-cell time-resolved microscopy, we discovered that the poorly characterized protein Kel1 serves as a major noise suppressor of the pathway. At the molecular level, Kel1 suppresses spontaneous activation of the pheromone response by inhibiting membrane recruitment of Ste5 and…
Role Of S-Nitrosylation In The Extrinsic Apoptotic Signalling Pathway In Cancer.
2015
One of the key features of tumour cells is the acquisition of resistance to apoptosis. Thus, determining therapeutic strategies that circumvent apoptotic resistance and result in tumor regression is a challenge. One strategy to induce apoptosis is to activate death receptor signalling pathways. Members of the Tumor Necrosis Factor TNF-family death receptors ligand (TRAIL, FasL and TNF-α) can originate from immune and non-immune cells. Death receptors, engaged by cognate ligands, can initiate multiple signaling pathways, which can generate diverse outcomes, including non-apoptosis-related signal. Knowledge on the molecular mechanisms (that determine death or survival of tumour cells) followi…
Docosahexaenoic acid protects human RPE cells against oxidative stress via PI3K/Akt m-TOR/p70-p85S6K pathways
2012
Purpose Oxidative Stress (OS) plays a critical role in the pathogenesis of age-related macular degeneration (AMD), especially by targeting the retinal pigment epithelium (RPE). Dietary habits with high consumption of docosahexaenoic acid (DHA) have been shown to prevent the development and evolution of AMD. Nevertheless, it is still unclear how DHA affects AMD. Our study aimed to investigate the involvement of the PI3K/Akt and m-TOR/p70-p85S6K pathways in human RPE cells after induction of OS, and then to assess the effect of DHA in the signaling pathways and in the protection against RPE cell death. Methods For this purpose, we used ARPE-19 cells exposed to the prooxidant agent, tert-butyl…