Search results for "fas Receptor"

Knockout of myeloid cell leukemia-1 induces liver damage and increases apoptosis susceptibility of murine hepatocytes

2008

Apoptosis, or programmed cell death, regulates tissue development and homeostasis in multi-cellular organisms. Extrinsic or intrinsic death signals activate pro-apoptotic pathways, resulting in the activation of caspases and finally in cell death. An important event during apoptosis process is the permeabilization of the outer mitochondrial membrane (OMM). Integrity of the OMM is regulated by the Bcl-2 protein family, which is divided into three groups: anti-apoptotic members Bcl-2, Bcl-xL and myeloid cell leukemia-1 (Mcl-1), pro-apoptotic multidomain members Bax and Bak, and pro-apoptotic BH3-only proteins. Mitochondrial activation is regulated by selective interactions of Bcl-2 proteins v…

NF-κB Inhibition Restores Sensitivity to Fas-Mediated Apoptosis in Lymphoma Cell Lines

2003

Failure to perform the Fas-related apoptosis pathway can account for tumor resistance both to chemotherapeutic agents and to immunological effectors. We studied the role of NK-kappaB in Fas-resistance, employing the Fas-sensitive human T-lymphoma HuT78 cell line and its Fas-resistant variants HuT78B1 and HuT78G9. All these cell lines expressed high levels of constitutively activated NF-kappaB. Pretreatment of cells with NF-kappaB inhibitors (PDTC, MG132, or SN50) strongly enhanced CH11-induced apoptosis in HuT78 and Hut78G9 cells, while only MG132 showed a similar potentiating effect in HuT78B1. The described synergism was significantly inhibited by pretreatment with the anti-Fas-blocking a…

Apoptosis in liver disease

2001

A variety of biological functions are regulated through extracellular signals. Amongst the best studied examples is growth control, which is achieved by the regulatory function of growth factors. In recent years it has become apparent that cell death (apoptosis) is controlled in a similar fashion. Apoptosis, firstly a morphologically defined process, is a highly controlled type of cell death that plays a critical role in embryonic development, deletion of autoreactive T-cells and adult tissue homoeostasis. There is increasing evidence that derangement of the apoptotic program is the underlying cause of a series of diseases including liver diseases. The deadly program can be initiated by lig…

Triclosan induces Fas receptor-dependent apoptosis in mouse neocortical neurons in vitro

2014

Triclosan (TCS) is a commonly used antimicrobial agent in personal care and sanitizing products, as well as in household items. Numerous studies have demonstrated the presence of TCS in various human tissues. Several studies have reported the accumulation of TCS in fish and human brain tissue. The aim of the present study was to investigate the effect of TCS on apoptosis in mouse neocortical neurons after 7 days of culture in vitro following 3, 6 and 24 h of exposure. To explore the mechanism underlying the effects of TCS in neurons, we studied the activation and protein expression of the Fas receptor (FasR) and caspase- 8, caspase-9 and caspase-3, as well as DNA fragmentation in TCS-treate…

dsRNA induces apoptosis through an atypical death complex associating TLR3 to caspase-8

2012

Toll-like receptor 3 (TLR3) is a pattern-recognition receptor known to initiate an innate immune response when stimulated by double-stranded RNA (dsRNA). Components of TLR3 signaling, including TIR domain-containing adapter inducing IFN-α (TRIF), have been demonstrated to contribute to dsRNA-induced cell death through caspase-8 and receptor interacting protein (RIP)1 in various human cancer cells. We provide here a detailed analysis of the caspase-8 activating machinery triggered in response to Poly(I:C) dsRNA. Engagement of TLR3 by dsRNA in both type I and type II lung cancer cells induces the formation of an atypical caspase-8-containing complex that is devoid of classical death receptors…

Role of GATA-1 and HSP70 in the Dyserythropoiesis of Early Myelodysplastic Syndromes.

2009

Abstract Abstract 3823 Poster Board III-759 Myelodysplastic syndromes (MDS) are heterogeneous hematopoietic stem cell disorders characterized by a hypercellular dysplastic bone marrow (BM) with peripheral blood cytopenias, mainly anemia. Early MDS with less than 10% BM blasts which belong in most cases to low and intermediate-1 (int-1) risk groups according to the International Prognostic Scoring System (IPSS), usually demonstrate dyserythropoiesis. The growth of erythroid progenitors is altered, with increased caspase activation leading to excessive cell death, and cellular dysplasia characterized, in liquid culture of CD34+-derived erythroid progenitors, by a delayed expression of the gly…

Drosophila melanogaster overexpression FAS live longer

2018

FAS and FAS ligand is critical in the control of the extension of extrinsic pathway of apoptosis. In previous studies we have performed transcriptomics peripheral blood cells from centenarians, octogenarians and young persons and we found over expression in centenarians of the FAS receptor. To confirm the role of FAS ligand in longevity across animal species, we have generated Drosophila melanogaster that over expresses this gene using the GAL4-UAS technique. The results show that flies overexpressing FAS increase maximal longevity in twelve percent and average longevity in six percent. Therefore, we confirm that FAS is related to longevity flight.

Post-Translational Regulation of Fas/CD95 in Cell Death and Survival: Role of Nitric Oxide

2010

Autoimmune thyroid disease: new models of cell death in autoimmunity

2002

Autoimmunity to thyroid antigens leads to two distinct pathogenic processes with opposing clinical outcomes: hypothyroidism in Hashimoto's thyroiditis and hyperthyroidism in Graves' disease. The high frequency of these diseases and easy accessibility of the thyroid gland has allowed the identification of key pathogenic mechanisms in organ-specific autoimmune diseases. In early investigations, antibody- and T-cell-mediated death mechanisms were proposed as being responsible for autoimmune thyrocyte depletion. Later, studies on apoptosis have provided new insights into autoimmune target destruction, indicating the involvement of death receptors and cytokine-regulated apoptotic pathways in the…

Effect of tauroursodeoxycholic acid on bile acid-induced apoptosis in primary human hepatocytes

2000

Background/aims The accumulation of endogenous bile acids contributes to hepatocellular damage during cholestatic liver disease. To evaluate the potential role of apoptotic cell death due to increased concentrations of bile acids, primary human hepatocytes were treated with hydrophobic and hydrophilic bile acids. Because the Fas receptor–ligand system may mediate apoptosis in human liver cells, the effect of toxic bile acids on hepatocellular Fas receptor expression was evaluated. Materials and methods Primary human hepatocytes were incubated with 50 and 100 μM glycochenodeoxycholic acid (GCDCA) and co-incubated with equimolar concentrations of tauroursodeoxycholic acid (TUDCA). To evaluate…