Search results for "death"
showing 10 items of 1744 documents
Dexamethasone treatment of naïve organ of Corti explants alters the expression pattern of apoptosis-related genes.
2009
Dexamethasone treatment of organ of Corti explants challenged with an ototoxic level of an inflammatory cytokine modulates NFkappaB signaling and the expression levels of both pro-and anti-apoptosis-related genes. It is not known if naïve organ of Corti explants will respond in a similar manner to treatment with a corticosteroid. This study examines the response of naïve organ of Corti explants to treatment with dexamethasone.Three-day-old rat organ of Corti explants were cultured for 1, 2, or 4 days. Four-day in vitro cultures were fixed, stained with FITC-phalloidin and hair cells were counted. ELISA was performed on 2-day cultures to determine the levels of phosphorylated nuclear factor …
8,8-bis-(Dihydroconiferyl)-diferulate displayed impressive cytotoxicity towards a panel of human and animal cancer cells
2020
Abstract Background Recalcitrant cancers appear as a major obstacle to chemotherapy, prompting scientists to intensify the search for novel drugs to tackle the cell lines expressing multi-drug resistant (MDR) phenotypes. Purpose The purpose of this study was to evaluate the antiproliferative potential of a ferrulic acid derivative, 8,8-bis-(dihydroconiferyl)-diferulate (DHCF2) on a panel of 18 cancer cell lines, including various sensitive and drug-resistant phenotypes, belonging to human and animals. The mode of induction of cell death by this compound was further studied. Methods The antiproliferative activity, autophagy, ferroptotic and necroptotic cell death were evaluated by the resazu…
Cytotoxicity of apigenin toward multiple myeloma cell lines and suppression of iNOS and COX-2 expression in STAT1-transfected HEK293 cells.
2020
Apigenin is one of the most abundant dietary flavonoids that possesses multiple bio-functions.This study was designed to determine the influence of apigenin on gene expressions, cancer cells, as well as STAT1/COX-2/iNOS pathway mediated inflammation and tumorigenesis in HEK293-STAT1 cells. Furthermore, the cytotoxic activity toward multiple myeloma (MM) cell lines was investigated.Bioinformatic analyses were used to predict the sensitivity and resistance of tumor cells toward apigenin and to determine cellular pathways influenced by this compound. The cytotoxic and ferroptotic activity of apigenin was examined by the resazurin reduction assay. Additionally, we evaluated apoptosis, and cell …
Pyrazolo[3,4-h]quinolines promising photosensitizing agents in the treatment of cancer.
2015
A new series of pyrazolo[3,4-h]quinolines, heteroanalogues of angelicin was conveniently prepared with a broad substitution pattern. A large number of derivatives was obtained and the cellular photocytotoxicity was evaluated in vitro against 5 different human tumor cell lines with GI50 values reaching the nanomolar level (14.52e0.04 mM). Selected compounds were able to photoinduce a massive cell death with the involvement of mitochondria. Their photodamage cellular targets were proteins and lipids and they did not cause any kind of DNA photodamage. This latter event is of considerable importance in the modulation of long term side effects, generally associated with the use of classical furo…
Calcium in plant defence‐signalling pathways
2006
In plant cells, the calcium ion is a ubiquitous intracellular second messenger involved in numerous signalling pathways. Variations in the cytosolic concentration of Ca2+ ([Ca2+]cyt) couple a large array of signals and responses. Here we concentrate on calcium signalling in plant defence responses, particularly on the generation of the calcium signal and downstream calcium-dependent events participating in the establishment of defence responses with special reference to calcium-binding proteins.
Side effects of oxysterols: cytotoxicity, oxidation, inflammation, and phospholipidosis.
2008
Oxysterols are 27-carbon atom molecules resulting from autoxidation or enzymatic oxidation of cholesterol. They are present in numerous foodstuffs and have been demonstrated to be present at increased levels in the plasma of patients with cardiovascular diseases and in atherosclerotic lesions. Thus, their role in lipid disorders is widely suspected, and they might also be involved in important degenerative diseases such as Alzheimer's disease, osteoporosis, and age-related macular degeneration. Since atherosclerosis is associated with the presence of apoptotic cells and with oxidative and inflammatory processes, the ability of some oxysterols, especially 7-ketocholesterol and 7β-hydrox…
Inhibition of proteasome function induces programmed cell death in proliferating endothelial cells.
2000
Proteolysis mediated by the ubiquitin-proteasome system has been implicated in the regulation of programmed cell death. Here we investigated the differential effects of proteasomal inhibitors on the viability of proliferating and quiescent primary endothelial cells in vitro and in vivo. Subconfluent, proliferating cells underwent carbobenzoxy-L-isoleucyl-gamma-t-butyl-L-glutamyl-L-alanyl-L-leucinal (PSI) -induced apoptosis at low concentrations (EC(50)=24 nM), whereas at least 340-fold higher concentrations of PSI were necessary to obtain the same effect in confluent, contact-inhibited cells. PSI-mediated cell death could be blocked by a caspase-3 inhibitor (Ac-DEVD-H), but not by a caspase…
µ-Calpain conversion of antiapoptotic Bfl-1 (BCL2A1) into a prodeath factor reveals two distinct alpha-helices inducing mitochondria-mediated apoptos…
2011
Anti-apoptotic Bfl-1 and pro-apoptotic Bax, two members of the Bcl-2 family sharing a similar structural fold, are classically viewed as antagonist regulators of apoptosis. However, both proteins were reported to be death inducers following cleavage by the cysteine protease µ-calpain. Here we demonstrate that calpain-mediated cleavage of full-length Bfl-1 induces the release of C-terminal membrane active α-helices that are responsible for its conversion into a pro-apoptotic factor. A careful comparison of the different membrane-active regions present in the Bfl-1 truncated fragments with homologous domains of Bax show that helix α5, but not α6, of Bfl-1 induces cell death and cytochrome c r…
Bax inhibitor-1 is likely a pH-sensitive calcium leak channel, not a H+/Ca2+ exchanger.
2014
The endoplasmic reticulum (ER) plays a key role in the synthesis, folding, and sorting of proteins, and disturbances of this delicate system can cause cell death. The ER also serves as the major intracellular calcium (Ca(2+)) store, and release of Ca(2+) from this store controls diverse cellular functions. At the interface of both these functions of the ER is Bax inhibitor-1 (BI-1), an evolutionarily conserved multifunctional protein that mediates Ca(2+) efflux from the ER and protects against ER stress. Several mechanisms have been proposed to explain how BI-1 might mediate Ca(2+) efflux from the ER. Chang et al. present structural evidence that a bacterial homolog of BI-1, BsYetJ, is a pH…
Phytochemical indicaxanthin suppresses 7-ketocholesterol-induced THP-1 cell apoptosis by preventing cytosolic Ca(2+) increase and oxidative stress.
2012
7-Ketocholesterol (7-KC)-induced apoptosis of macrophages is considered a key event in the development of human atheromas. In the present study, the effect of indicaxanthin (Ind), a bioactive pigment from cactus pear fruit, on 7-KC-induced apoptosis of human monocyte/macrophage THP-1 cells was investigated. A pathophysiological condition was simulated by using amounts of 7-KC that can be reached in human atheromatous plaque. Ind was assayed within a micromolar concentration range, consistent with its plasma level after dietary supplementation with cactus pear fruit. Pro-apoptotic effects of 7-KC were assessed by cell cycle arrest, exposure of phosphatidylserine at the plasma membrane, varia…