scholarly journals Caspase-8 and Caspase-3 Are Expressed by Different Populations of Cortical Neurons Undergoing Delayed Cell Death after Focal Stroke in the Rat

1999 ◽  
Vol 19 (14) ◽  
pp. 5932-5941 ◽  
Author(s):  
James J. Velier ◽  
Julie A. Ellison ◽  
Kristine K. Kikly ◽  
Patricia A. Spera ◽  
Frank C. Barone ◽  
...  
Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2177-2177
Author(s):  
Duncan H Mak ◽  
Christa Manton ◽  
Michael Andreeff ◽  
Bing Z Carter

Abstract Abstract 2177 The antiapoptotic function of the inhibitors of apoptosis family of proteins (IAPs) is antagonized by mitochondria-released SMAC protein. The IAP-member XIAP suppresses apoptosis by directly binding and inhibiting caspase-9 and caspase-3, while cIAP1, a component of the cytoplasmic signaling complex containing TNF receptor associated factors, suppresses apoptosis via the caspase-8-mediated pathway. BV-6 (Genentech) is a bivalent SMAC-mimetic and has been shown to promote cell death by inducing cIAP autoubiquitination, NF-κB activation, and TNFα-dependent apoptosis. We examined its effect on leukemic cells and found that BV-6 only moderately induced apoptosis. The EC50 was found to be 15.3±5.1 μM at 48 hours in OCI-AML3 cells which are relatively sensitive. We then determined whether BV-6 sensitizes leukemic cells to the HDM2-inhibitor nutlin-3a and to Ara-C. p53 modulates the expression and activity of Bcl-2 family proteins and promotes the mitochondrial-mediated apoptosis. We showed previously that activation of p53 by nutlin-3a sensitizes AML cells to XIAP inhibition induced-death in part by promoting the release of SMAC from mitochondrion (Carter BZ et al., Blood 2010). We treated OCI-AML3 cells with BV-6, nutlin-3a or Ara-C, and BV-6+nutlin-3a or BV-6+Ara-C and found that the combination of BV-6 and nutlin-3a or BV-6 and Ara-C synergistically induced cell death in OCI-AML3 cells with a combination index (CI) of 0.27±0.11 and 0.22±0.05 (48 hours), respectively. To demonstrate that p53 activation is essential for the synergism of BV-6+nutlin-3a combination, we treated OCI-AML3 vector control and p53 knockdown cells with these two agents and found that the combination synergistically promoted cell death in the vector control (CI=0.47±0.15) but not in the p53 knockdown cells, as expected, while BV6+Ara-C was synergistic in both vector control and p53 knockdown cells (CI=0.15±0.03 and 0.08±0.03, respectively, 48 hours). BV-6 induced activation of caspase-8, caspase-9, and caspase-3 and decreased XIAP levels, but did not cause rapid cIAP1 degradation, as reported by others. To assess the contribution of death receptor-mediated apoptosis in BV-6-induced cell death, we treated Jurkat and caspase-8 mutated Jurkat cells (JurkatI9.2) with BV-6 and found that BV-6 induced cell death and significantly potentiated TRAIL-induced apoptosis in Jurkat cells (CI=0.14±0.08, 48 hours). Caspase-8 mutated JurkatI9.2 cells were significantly less sensitive to BV-6 than Jurkat cells and as expected, JurkatI9.2 was completely resistant to TRAIL. Collectively, we showed that the bivalent SMAC-mimetic BV-6 potentiates p53 activation-, chemotherapy-, and TRAIL-induced cell death, but has only minimal activity by itself in leukemic cells. SMAC-mimetics could be useful in enhancing the efficacy of different classes of therapeutic agents used in AML therapy. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 330-330
Author(s):  
Antonia Cagnetta ◽  
Michele Cea ◽  
Chirag Acharya ◽  
Teresa Calimeri ◽  
Yu-Tzu Tai ◽  
...  

Abstract Abstract 330 Background: Our previous study demonstrated that inhibition of nicotinamide phosphoribosyltransferase (Nampt) acts by severely depleting intracellular NAD+ content and thus eliciting mitochondrial dysfunction and autophagic MM cell death. The proteasome inhibitor Bortezomib induces anti-MM activity by affecting a variety of signaling pathways. However, as with other agents, dose-limiting toxicities and the development of resistance limit its long-term utility. Here, we demonstrate that combining Nampt inhibitor and bortezomb induces synergistic anti-MM cell death both in vitro using MM cell lines or patient CD138+ MM cells and in vivo in a human plasmacytoma xenograft mouse model. Material and Methods: We utilized MM.1S, MM.1R, RPMI-8226, and U266 human MM cell lines, as well as purified tumor cells from patients relapsing after prior therapies. Cell viability and apoptosis assays were performed using Annexin V/PI staining. Intracellular NAD+ level and proteasome activity were quantified after 12, 24, and 48h exposure to single/combination drugs by specific assays. In vitro angiogenesis was assessed by Matrigel capillary-like tube structure formation assay. Immunoblot analysis was performed using antibodies to caspase-8, caspase-9, caspase-3, PARP, Bcl-2, and tubulin. CB-17 SCID male mice (n = 28; 7 mice/EA group) were subcutaneously inoculated with 5.0 × 106 MM.1S cells in 100 microliters of serum free RPMI-1640 medium. When tumors were measurable (3 weeks after MM cell injection), mice were treated for three weeks with vehicle alone, FK866 (30mg/kg 4 days weekly), Bortezomib (0.5 mg/kg twice weekly), or FK866 (30 mg/kg) plus Bortezomib (0.5 mg/kg). Statistical significance of differences observed in FK866, Bortezomib or combination-treated mice was determined using a Student t test. Isobologram analysis was performed using “CalcuSyn” software program. A combination index < 1.0 indicates synergism. Results/Discussion: Combining FK866 and Bortezomib induces synergistic anti-MM activity in vitro against MM cell lines (P<0.005, CI < 1) or patient CD138-positive MM cells (P< 0.004). FK866 plus Bortezomib-induced synergistic effect is associated with: 1)activation of caspase-8, caspase-9, caspase-3, and PARP; 2) improved intracellular NAD+ dissipation; 3) suppression of chymotrypsin-like, caspase-like, and trypsin-like proteolytic activities; 4) inhibition of NF-kappa B signaling; and 5) inhibition of angiogenesis. Importantly, the ectopic overexpression of Nampt rescues this observed synergistic effect; conversely, Nampt knockdown by RNAi significantly enhances the anti-MM effect of bortezomib. In the murine xenograft MM model, low dose combination FK866 (30 mg/kg) and Bortezomib (0.5 mg/kg) is well tolerated, significantly inhibits tumor growth (P < 0.001), and prolongs host survival (2–2.5 months in mice receiving combined drugs, P = 0.001). These findings demonstrate that intracellular NAD+ levels represent a major determinant in the ability of bortezomib to induce apoptosis of MM cells, providing the rationale for clinical protocols evaluating FK866 together with Bortezomib to improve patient outcome in MM. Disclosures: Munshi: Celgene: Consultancy; Millenium: Consultancy; Merck: Consultancy; Onyx: Consultancy.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 251-251
Author(s):  
Patrice N. Wagner ◽  
Qiong Shi ◽  
Yuri D. Fedoriw ◽  
Sandra S. Zinkel

Abstract Multicellular organisms remove damaged or superfluous cells through a highly regulated cellular process known as programmed cell death. There are two main forms of programmed cell death, apoptosis and necrosis. Necrosis (necroptosis) previously thought to be an unregulated death pathway was recently found to be highly regulated. The manner by which a cell dies has important implications. In apoptotic cell death, caspases digest the cell to cause implosion in an immunologically silent process. In necroptotic cell death, increased Rip kinase signaling effects rupture of the plasma membrane, cellular explosion, and the activation of an inflammatory response. Death receptors, such as the TNFα receptor, can activate either apoptotic or necroptotic death. The upstream activators and transducers including Caspase-8, Rip1, and Fadd, are common to both forms of cell death. Interestingly, Caspase-8 and c-FlipL, a caspase homolog, were recently shown to inhibit the necrotic pathway during embryonic development through the formation of a catalytically active complex. The BH3-only Bcl-2 family member, Bid is one of the strongest substrates of Caspase-8, placing it at the interface of the apoptotic and necroptotic pathways, and in position to mediate cell death fate. The role of apoptosis in hematopoietic homeostasis has been well characterized. We developed a mouse model of unrestrained necroptosis in order to determine how unrestrained necroptosis impacts hematopoietic homeostasis and bone marrow function. To do this we generated a mouse model in which apoptosis is prevented by the deletion of the pro-apoptotic effectors Bax and Bak. We further deleted the upstream activator Bid (VavBaxBakBid TKO mice). Surprisingly, these mice die of bone marrow failure due to unrestrained necroptotic cell death. TKO bone marrow displays necroptotic cells by electron microscopy, and markedly increased Rip1 expression by immunofluorescence. TKO mice die of bone marrow failure with marked myeloid dysplasia between the age of 3 and 12 months, and a small number develop leukemia, a phenotype that closely resembles MDS. Further analysis revealed expansion and increased BrdU incorporation of the SLAM-HSC population, consistent with increased HSC proliferation in response to death of more mature cells. To assess function of these HSCs, we performed competitive reconstitution assays. TKO bone marrow initially outcompetes WT bone marrow, but the mice eventually succumb to bone marrow failure beginning at 5 months post–transplantation, despite the presence of ~10-15% wild type bone marrow. These results demonstrate that increased necroptotic signaling results in a cell autonomous stem cell defect. In addition, the presence of necroptotic bone marrow also kills normal HSCs in a non cell-autonomous manner, due to a feed-forward inflammatory process. To further characterize how necroptotic cell death is regulated, we developed myeloid progenitor cell lines (MPCs) from the bone marrow of WT, Bid KO, BaxBak DKO, and BaxBakBid TKO mice to facilitate biochemical and mechanistic studies. Our studies demonstrated increased activation (phosphorylation) and markedly increased levels of Rip1 in the pronecrotic complex (Complex II) with Rip3, Caspase-8, and Fadd in our TKO MPCs following LPS treatment. This association of Rip1 with Complex II is abrogated by reintroduction of Bid by retrovirus into TKO MPCs, demonstrating that Bid inhibits Rip1 association with complex II, suggesting that Bid is a key factor that determines cell death fate. Increased bone marrow cell death is well documented in MDS. To determine if necroptosis plays a role in this bone marrow cell death, we evaluated RIP1 and Caspase 3 expression in 17 human MDS samples. Remarkably, we found increased RIP1 expression, but not activated caspase 3 in bone marrow samples from patients with the RCMD, RAEB-1, and RAEB-2 subtype of MDS, but not in 4 control bone marrow samples (normal lymphoma staging marrows). Our study thus demonstrates that increased necroptosis signaling can result in bone marrow failure with dysplasia, and that necroptotic cell death signaling is increased in bone marrow from MDS patients, highlighting the potential importance of this targetable signaling pathway in bone marrow failure disorders such as MDS. Disclosures No relevant conflicts of interest to declare.


2011 ◽  
Vol 89 (4) ◽  
pp. 552-561 ◽  
Author(s):  
Nobuyuki Kuramoto ◽  
Keiichi Seko ◽  
Chie Sugiyama ◽  
Makoto Shuto ◽  
Kiyokazu Ogita

2003 ◽  
Vol 98 (5) ◽  
pp. 1119-1127 ◽  
Author(s):  
Dara Ditsworth ◽  
Margaret A. Priestley ◽  
Andreas W. Loepke ◽  
Chandra Ramamoorthy ◽  
John McCann ◽  
...  

Background Deep hypothermic circulatory arrest (DHCA), as used in infant heart surgery, carries a risk of brain injury. In a piglet DHCA model, neocortical neurons appear to undergo apoptotic death. Caspases, cytochrome c, tumor necrosis factor (TNF), and Fas play a role in apoptosis in many ischemic models. This study examined the expression of these factors in a DHCA piglet model. Methods Thirty-nine anesthetized piglets were studied. After cardiopulmonary bypass (CPB) cooling of the brain temperature to 19 degrees C, DHCA was induced for 90 min, followed by CPB rewarming. After separation from CPB, piglets were killed at 1, 4, 8, 24, and 72 h and 1 week. Caspase-8 and -3 activity, and concentrations of TNF-alpha, Fas, Fas-ligand, cytochrome c, and adenosine triphosphate (ATP) were measured in the neocortex by enzymatic assay and Western blot analysis. Caspase-8 and -3 activity and cell death were examined histologically. Significance was set at P &lt; 0.05. Results In neocortex, damaged neurons were not observed in control (no CPB), rarely observed in CPB (no DHCA), and rarely observed in the DHCA 1-h, 4-h, and 1-week reperfusion groups. However, they were seen frequently in the DHCA 8-, 24-, and 72-h reperfusion groups. Although neuronal death was widespread 8-72 h after DHCA, cortical ATP concentrations remained unchanged from control. Both caspase-3 and -8 activities were significantly increased at 8 h after DHCA, and caspase-3 concentration remained elevated for as long as 72 h. Caspase-3 and -8 activity was also observed in damaged neocortical neurons. Cytosolic cytochrome c and Fas were significantly expressed at 1 h and 4 h after DHCA, respectively. Fas-ligand and TNF-alpha were not observed in any group. Conclusion After DHCA, induction of apoptosis in the neocortex occurs within a few hours of reperfusion and continues for several days. Increased Fas, cytochrome c, and caspase concentrations, coupled with normal brain ATP concentrations and apoptotic histologic appearance, are consistent with the occurrence of apoptotic cell death.


2017 ◽  
Vol 45 (07) ◽  
pp. 1497-1511 ◽  
Author(s):  
Shinya Okubo ◽  
Takuhiro Uto ◽  
Aya Goto ◽  
Hiroyuki Tanaka ◽  
Tsuyoshi Nishioku ◽  
...  

Berberine (BBR), an isoquinoline alkaloid, is a well-known bioactive compound contained in medicinal plants used in traditional and folk medicines. In this study, we investigated the subcellular localization and the apoptotic mechanisms of BBR were elucidated. First, we confirmed the incorporation of BBR into the cell visually. BBR showed antiproliferative activity and promptly localized to the nucleus from 5[Formula: see text]min to 15[Formula: see text]min after BBR treatment in HL-60 human promyelocytic leukemia cells. Next, we examined the antiproliferative activity of BBR (1) and its biosynthetically related compounds (2-7) in HL-60 cells. BBR exerted strongest antiproliferative activity among 1-7 and the results of structures and activity relation suggested that a methylenedioxyl group in ring A, an [Formula: see text]-alkyl group at C-9 position, and the frame of isoquinoline may be necessary for antiproliferative activity. Moreover, BBR showed the most potent antiproliferative activity in HL-60 cells among human cancer and normal cell lines tested. Next, we examined the effect of BBR on molecular events known as apoptosis induction. In HL-60 cells, BBR induced chromatin condensation and DNA fragmentation, and triggered the activation of PARP, caspase-3 and caspase-8 without the activation of caspase-9. BBR-induced DNA fragmentation was abolished by pretreatment with inhibitors against caspase-3 and caspase-8, but not against caspase-9. ERK and p38 were promptly phosphorylated after 15 min of BBR treatment, and this was correlated with time of localization to the nucleus of BBR. These results demonstrated that BBR translocated into nucleus immediately after treatments and induced apoptotic cell death by activation of caspase-3 and caspase-8.


Reproduction ◽  
2006 ◽  
Vol 132 (3) ◽  
pp. 465-475 ◽  
Author(s):  
Marina C Peluffo ◽  
Leonardo Bussmann ◽  
Richard L Stouffer ◽  
Marta Tesone

Apoptosis is associated with the regression of the corpus luteum (CL) in many species. Since caspases play a central role in apoptosis, we studied several initiators (-2, -8, and -9) and the main effector (-3) caspase in the CL during the estrous cycle of the rat. Two different populations of CL (old and new) were identified on ovaries at estrus and diestrus II (DII). Diminished (P< 0.05) luteal progesterone content and P450scc levels suggested that functional luteolysis occurred between the new CL at DII and old CL at estrus, whereas the decline (P< 0.05) in luteal weight indicated that structural regression was occurring between old CL at estrus to DII. Immunostaining for caspase-2 in luteal and endothelial cells appeared to increase as the luteal phase progressed, peaking at DII in the old CL. However, caspase-8 and -9 immunostaining showed little change with a slight increase at estrus in the old population. Notably, caspase-3 staining appeared to peak at DII in the new CL. Enzyme activity of caspase-9 increased (P< 0.05) in the new CL at DII, followed by that of caspase-2 and -3 in old CL at estrus. Caspase-8 activity did not change at any stage. The number of apoptotic cells increased at DII in the old CL. These results suggest an important role for this protease family during early events of luteolysis in the rat estrous cycle.


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