Search results for "BCL-2"
showing 10 items of 197 documents
α-Tocopherol impairs 7-ketocholesterol-induced caspase-3-dependent apoptosis involving GSK-3 activation and Mcl-1 degradation on 158N murine oligoden…
2011
Abstract In important and severe neurodegenerative pathologies, 7-ketocholesterol, mainly resulting from cholesterol autoxidation, may contribute to dys- or demyelination processes. On various cell types, 7-ketocholesterol has often been shown to induce a complex mode of cell death by apoptosis associated with phospholipidosis. On 158N murine oligodendrocytes treated with 7-ketocholesterol (20 μg/mL corresponding to 50 μM, 24–48 h), the induction of a mode of cell death by apoptosis characterised by the occurrence of cells with condensed and/or fragmented nuclei, caspase activation (including caspase-3) and internucleosomal DNA fragmentation was observed. It was associated with a loss of tr…
MYC and EGR1 synergize to trigger tumor cell death by controlling NOXA and BIM transcription upon treatment with the proteasome inhibitor bortezomib
2014
The c-MYC (MYC afterward) oncogene is well known for driving numerous oncogenic programs. However, MYC can also induce apoptosis and this function of MYC warrants further clarification. We report here that a clinically relevant proteasome inhibitor significantly increases MYC protein levels and that endogenous MYC is necessary for the induction of apoptosis. This kind of MYC-induced cell death is mediated by enhanced expression of the pro-apoptotic BCL2 family members NOXA and BIM. Quantitative promoter-scanning chromatin immunoprecipitations (qChIP) further revealed binding of MYC to the promoters of NOXA and BIM upon proteasome inhibition, correlating with increased transcription. Both pr…
Transmembrane BAX Inhibitor-1 Motif Containing Protein 5 (TMBIM5) Sustains Mitochondrial Structure, Shape, and Function by Impacting the Mitochondria…
2020
The Transmembrane Bax Inhibitor-1 motif (TMBIM)-containing protein family is evolutionarily conserved and has been implicated in cell death susceptibility. The only member with a mitochondrial localization is TMBIM5 (also known as GHITM or MICS1), which affects cristae organization and associates with the Parkinson&rsquo
Peptides Derived from the Transmembrane Domain of Bcl-2 Proteins as Potential Mitochondrial Priming Tools
2014
The Bcl-2 family of proteins is crucial for apoptosis regulation. Members of this family insert through a specific C-terminal anchoring trans membrane domain (TMD) in the mitochondrial outer membrane where they hierarchically interact to determine cell fate. While the mitochondrial membrane has been proposed to actively participate in these protein protein interactions, the influence of the TMD in the membrane-mediated interaction is poorly understood. Synthetic peptides (TMD-pepts) corresponding to the putative TMD of antiapoptotic (Bcl-2, Bcl-xL, Bcl-w, and Mcl-1) and pro-apoptotic (Bax, Bak) members were synthesized and characterized. TMD-pepts bound more efficiently to mitochondria-like…
Rho protein inactivation induced apoptosis of cultured human endothelial cells.
2002
Small GTP-binding Rho GTPases regulate important signaling pathways in endothelial cells, but little is known about their role in endothelial cell apoptosis. Clostridial cytotoxins specifically inactivate GTPases by glucosylation [ Clostridium difficile toxin B-10463 (TcdB-10463), C. difficile toxin B-1470 (TcdB-1470)] or ADP ribosylation ( C. botulinum C3 toxin). Exposure of human umbilical cord vein endothelial cells (HUVEC) to TcdB-10463, which inhibits RhoA/Rac1/Cdc42, or to C3 toxin, which inhibits RhoA, -B, -C, resulted in apoptosis, whereas inactivation of Rac1/Cdc42 with TcdB-1470 was without effect, suggesting that Rho inhibition was responsible for endothelial apoptosis. Disruptio…
Rho prevents apoptosis through Bcl-2 expression: Implications for interleukin-2 receptor signal transduction
1997
Here we describe a Rho-mediated apoptosis suppression pathway driven by Bcl-2 expression in the interleukin (IL)-4- or IL-2-dependent murine T cell line TS1 alpha beta. IL-2, but not IL-4, induces Bcl-2 expression through RhoA activation which is inhibited by the specific Rho family inhibitor, Clostridium difficile Toxin B, as well as by a dominant negative RhoA mutant. Using transient transfections of RhoA mutants tagged with the vesicular stomatitis virus glycoprotein, we show that a constitutively active RhoA mutant induces Bcl-2 expression and prevents apoptosis upon IL-4 withdrawal. Finally, we have identified the signaling pathway involved together with RhoA in Bcl-2 induction and sho…
Hamster Bcl-2 Protein Is Cleaved in Vitro and in Cells by Caspase-9 and Caspase-3
2001
Full-length cDNA of hamster bcl-2 (771 nt) was cloned by RT-PCR and inserted into pGEX-4T-1 to produce the recombinant hamster Bcl-2 protein. The purified recombinant Bcl-2 protein (26.4 kDa) was used as a substrate for the active human caspase-3 and caspase-9 in vitro. It is shown here that Bcl-2 is efficiently cleaved by caspase-3 to a 23 kDa fragment. Although not possessing a putative caspase-9 cleavage site in its sequence, hamster Bcl-2 was also cleaved by caspase-9 into exactly the same 23 kDa cleavage product, indicating that cleavage occurred at the same site. Caspase-3- and caspase-9-mediated cleavage of Bcl-2 was efficiently blocked by caspase-3 (zDEVD) and caspase-9 (zLEHD) inhi…
SAHA/TRAIL combination induces detachment and anoikis of MDA-MB231 and MCF-7 breast cancer cells
2012
Abstract SAHA, an inhibitor of histone deacetylase activity, has been shown to sensitize tumor cells to apoptosis induced by TRAIL, a member of TNF-family. In this paper we investigated the effect of SAHA/TRAIL combination in two breast cancer cell lines, the ERα−positive MCF-7 and the ERα−negative MDA-MB231. Treatment of MDA-MB231 and MCF-7 cells with SAHA in combination with TRAIL caused detachment of cells followed by anoikis, a form of apoptosis which occurs after cell detachment, while treatment with SAHA or TRAIL alone did not produce these effects. The effects were more evident in MDA-MB231 cells, which were chosen for ascertaining the mechanism of SAHA/TRAIL action. Our results show…
A new vicious cycle involving glutamate excitotoxicity, oxidative stress and mitochondrial dynamics
2011
Glutamate excitotoxicity leads to fragmented mitochondria in neurodegenerative diseases, mediated by nitric oxide and S-nitrosylation of dynamin-related protein 1, a mitochondrial outer membrane fission protein. Optic atrophy gene 1 (OPA1) is an inner membrane protein important for mitochondrial fusion. Autosomal dominant optic atrophy (ADOA), caused by mutations in OPA1, is a neurodegenerative disease affecting mainly retinal ganglion cells (RGCs). Here, we showed that OPA1 deficiency in an ADOA model influences N-methyl-D-aspartate (NMDA) receptor expression, which is involved in glutamate excitotoxicity and oxidative stress. Opa1enu/+mice show a slow progressive loss of RGCs, activation …
Vesicle transport and photoreceptor death: fishing for molecular links.
2013
Intracellular vesicle transport defects can induce retinal degeneration and photoreceptor cell death, but the molecular connections between these processes remains poorly understood. Reporting in Developmental Cell, Nishiwaki et al. (2013) suggest that a vesicle fusion cis-SNARE complex component translates vesicular transport defects into photoreceptor cell apoptosis.