scholarly journals Commitment and Effector Phases of the Physiological Cell Death Pathway Elucidated with Respect to Bcl-2, Caspase, and Cyclin-Dependent Kinase Activities

1998 ◽  
Vol 18 (5) ◽  
pp. 2912-2922 ◽  
Author(s):  
Kevin J. Harvey ◽  
James F. Blomquist ◽  
David S. Ucker
Keyword(s):  
Cell Death ◽  
Caspase 3 ◽  
Chromatin Condensation ◽  
Cysteine Proteases ◽  
Death Process ◽  
Common Mechanism ◽  
Cyclin Dependent Kinase ◽  
Conserved Sequence ◽  
Cell Death Pathway ◽  
Physiological Cell Death

ABSTRACT Physiological cell deaths occur ubiquitously throughout biology and have common attributes, including apoptotic morphology with mitosis-like chromatin condensation and prelytic genome digestion. The fundamental question is whether a common mechanism of dying underlies these common hallmarks of death. Here we describe evidence of such a conserved mechanism in different cells induced by distinct stimuli to undergo physiological cell death. Our genetic and quantitative biochemical analyses of T- and B-cell deaths reveal a conserved pattern of requisite components. We have dissected the role of cysteine proteases (caspases) in cell death to reflect two obligate classes of cytoplasmic activities functioning in an amplifying cascade, with upstream interleukin-1β-converting enzyme-like proteases activating downstream caspase 3-like caspases. Bcl-2 spares cells from death by punctuating this cascade, preventing the activation of downstream caspases while leaving upstream activity undisturbed. This observation permits an operational definition of the stages of the cell death process. Upstream steps, which are necessary but not themselves lethal, are modulators of the death process. Downstream steps are effectors of, and not dissociable from, actual death; the irreversible commitment to cell death reflects the initiation of this downstream phase. In addition to caspase 3-like proteases, the effector phase of death involves the activation in the nucleus of cell cycle kinases of the cyclin-dependent kinase (Cdk) family. Nuclear recruitment and activation of Cdk components is dependent on the caspase cascade, suggesting that catastrophic Cdk activity may be the actual effector of cell death. The conservation of the cell death mechanism is not reflected in the molecular identity of its individual components, however. For example, we have detected different cyclin-Cdk pairs in different instances of cell death. The ordered course of events that we have observed in distinct cases reflects essential thematic elements of a conserved sequence of modulatory and effector activities comprising a common pathway of physiological cell death.

scholarly journals Condensin I recruitment and uneven chromatin condensation precede mitotic cell death in response to DNA damage

2006 ◽  
Vol 174 (2) ◽  
pp. 195-206 ◽  
Author(s):  
Michael Blank ◽  
Yaniv Lerenthal ◽  
Leonid Mittelman ◽  
Yosef Shiloh
Keyword(s):  
Dna Damage ◽  
Cell Death ◽  
Chromatin Condensation ◽  
Mitotic Cell ◽  
Clear Distinction ◽  
Death Process ◽  
Cyclin Dependent Kinase ◽  
Mitotic Abnormalities ◽  
Cell Death Process ◽  
Mitotic Chromatin

Mitotic cell death (MCD) is a prominent but poorly defined form of death that stems from aberrant mitosis. One of the early steps in MCD is premature mitosis and uneven chromatin condensation (UCC). The mechanism underlying this phenomenon is currently unknown. In this study, we show that DNA damage in cells with a compromised p53-mediated G2/M checkpoint triggers the unscheduled activation of cyclin-dependent kinase 1 (Cdk1), activation and chromatin loading of the condensin I complex, and UCC followed by the appearance of multimicronucleated cells, which is evidence of MCD. We demonstrate that these processes engage some of the players of normal mitotic chromatin packaging but not those that drive the apoptotic chromatin condensation. Our findings establish a link between the induction of DNA damage and mitotic abnormalities (UCC) through the unscheduled activation of Cdk1 and recruitment of condensin I. These results demonstrate a clear distinction between the mechanisms that drive MCD-associated and apoptosis-related chromatin condensation and provide mechanistic insights and new readouts for a major cell death process in treated tumors.

scholarly journals Lamin proteolysis facilitates nuclear events during apoptosis.

1996 ◽  
Vol 135 (6) ◽  
pp. 1441-1455 ◽  
Author(s):  
L Rao ◽  
D Perez ◽  
E White
Keyword(s):  
Cell Death ◽  
Aspartic Acid ◽  
Transcriptional Activation ◽  
Chromatin Condensation ◽  
Interleukin 1 ◽  
Cysteine Proteases ◽  
Lamin A ◽  
Nuclear Lamins ◽  
Cell Death Pathway ◽  
Nuclear Events

Expression of the adenovirus E1A oncogene stimulates both cell proliferation and p53-dependent apoptosis in rodent cells. p53 implements apoptosis in all or in part through transcriptional activation of bax, the product of which promotes cell death. The adenovirus E1B 19K product is homologous in sequence and in function to Bcl-2, both of which bind to and inhibit the activity of Bax and thereby suppress apoptosis. The E1B 19K protein also interacts with the nuclear lamins, but the role of this interaction in the regulation of apoptosis is not known. Lamins are, however, substrates for members of the interleukin-1 beta-converting enzyme (ICE) family of cysteine proteases that are activated during apoptosis and function downstream of Bcl-2 in the cell death pathway. lamins are degraded during E1A-induced p53-dependent apoptosis. Lamin A and C are cleaved into 47- and 37-kD fragments, respectively, and the site of proteolysis is mapped to a conserved aspartic acid residue at position 230. The cleavage of lamins during apoptosis is consistent with the activation of an ICE-related cysteine protease down-stream of p53. No lamin protease activity was detected in cells expressing the E1B 19K protein, indicating that 19K functions upstream of protease activation in inhibiting apoptosis. Substitution of the aspartic acid at the cleavage site produced a mutant lamin protein that was resistant to proteolysis both in vitro and in vivo. Expression of uncleavable mutant lamin A or B attenuated apoptosis, delaying cell death and the associated DNA fragmentation by 12 h. Mutant lamin expressing cells failed to show the signs of chromatin condensation and nuclear shrinkage typical of cell death by apoptosis. Instead, the nuclear envelope collapsed and the nuclear lamina remained intact. However, the late stage of apoptosis was morphologically unaltered and formation of apoptotic bodies was evident. Thus, lamin breakdown by proteolytic degradation facilitates the nuclear events of apoptosis perhaps by facilitating nuclear breakdown.

Two steroidal saponins from Camassia cusickii induce L1210 cell death through the apoptotic mechanism

2001 ◽  
Vol 79 (11) ◽  
pp. 953-958 ◽  
Author(s):  
Ellyawati Candra ◽  
Kimihiro Matsunaga ◽  
Hironori Fujiwara ◽  
Yoshihiro Mimaki ◽  
Yutaka Sashida ◽  
...  
Keyword(s):  
Cell Death ◽  
Caspase 3 ◽  
Apoptotic Cell ◽  
Chromatin Condensation ◽  
Flow Cytometric Analysis ◽  
Apoptotic Cell Death ◽  
Morphological Observation ◽  
Steroidal Saponin ◽  
Steroidal Saponins ◽  
L1210 Cells

Two steroidal saponins, tigogenin hexasaccharide-1 (TGHS-1, (25R)-5α-spirostan-3β-yl 4-O-[2-O-[3-O- (α-L-rhamnopyranosyl)-β-D-glucopyranosyl]-3-O-[4-O-(α-L-rhamnopyranosyl)-β-D-glucopyranosyl]-β-D-glucopyranosyl]- β-D-galactopyranoside) and tigogenin hexasaccharide-2 (TGHS-2, (25R)-5α-spirostan-3β-yl 4-O-[2-O-[3-O- (β-D-glucopyranosyl)-β-D-glucopyranosyl]-3-O-[4-O-(α-L-rhamnopyranosyl)-β-D-glucopyranosyl]-β-D-glucopyranosyl]- β-D-galactopyranoside), were isolated from the fresh bulbs of Camassia cusickii. In murine leukemic L1210 cells, both compounds showed cytotoxicity with an EC50 value of 0.06 µM. The morphological observation revealed that TGHS-1 and TGHS-2 induced shrinkage in cell soma and chromatin condensation, suggesting apoptotic cell death. The cell death was confirmed to be apoptosis by Annexin V binding to phosphatidylserine in the cell membrane and excluding propidium iodide. A typical apoptotic DNA ladder and the cleavage of caspase-3 were observed after treatment with TGHS-1 and TGHS-2. In the presence of both the compounds, cells with sub-G1 DNA content were detected by flow cytometric analysis, indicating that TGHS-1 and TGHS-2 (each EC50 value of 0.1 µM) are the most powerful apoptotic saponins known. These results suggest that TGHS-1 and TGHS-2 induce apoptotic cell death through caspase-3 activation.Key words: steroidal saponin, tigogenin hexasaccharide, apoptosis, DNA fragmentation, murine leukemic L1210 cells.

Increased cell death in osteopontin-deficient cardiac fibroblasts occurs by a caspase-3-independent pathway

2004 ◽  
Vol 287 (4) ◽  
pp. H1730-H1739 ◽  
Author(s):  
Ron Zohar ◽  
Baoqian Zhu ◽  
Peter Liu ◽  
Jaro Sodek ◽  
C. A. McCulloch
Keyword(s):  
Cell Death ◽  
Caspase 3 ◽  
Cardiac Fibroblasts ◽  
Chromatin Condensation ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Tunel Staining ◽  
Wild Type ◽  
Nuclear Fragmentation ◽  
A Cell

Reperfusion-induced oxidative injury to the myocardium promotes activation and proliferation of cardiac fibroblasts and repair by scar formation. Osteopontin (OPN) is a proinflammatory cytokine that is upregulated after reperfusion. To determine whether OPN enhances fibroblast survival after exposure to oxidants, cardiac fibroblasts from wild-type (WT) or OPN-null (OPN−/−) mice were treated in vitro with H2O2to model reperfusion injury. Within 1 h, membrane permeability to propidium iodide (PI) was increased from 5 to 60% in OPN−/−cells but was increased to only 20% in WT cells. In contrast, after 1–8 h of treatment with H2O2, the percent of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-stained cells was more than twofold higher in WT than OPN−/−cells. Electron microscopy of WT cells treated with H2O2showed chromatin condensation, nuclear fragmentation, and cytoplasmic and nuclear shrinkage, which are consistent with apoptosis. In contrast, H2O2-treated OPN−/−cardiac fibroblasts exhibited cell and nuclear swelling and membrane disruption that are indicative of cell necrosis. Treatment of OPN−/−and WT cells with a cell-permeable caspase-3 inhibitor reduced the percentage of TUNEL staining by more than fourfold in WT cells but decreased staining in OPN−/−cells by ∼30%. Although the percentage of PI-permeable WT cells was reduced threefold, the percent of PI-permeable OPN−/−cells was not altered. Restoration of OPN expression in OPN−/−fibroblasts reduced the percentage of PI-permeable cells but not TUNEL staining after H2O2treatment. Thus H2O2-induced cell death in OPN-deficient cardiac fibroblasts is mediated by a caspase-3-independent, necrotic pathway. We suggest that the increased expression of OPN in the myocardium after reperfusion may promote fibrosis by protecting cardiac fibroblasts from cell death.

PANDER-induced cell-death genetic networks in islets reveal central role for caspase-3 and cyclin-dependent kinase inhibitor 1A (p21)

Gene ◽  
2006 ◽  
Vol 369 ◽  
pp. 134-141 ◽  
Author(s):  
Brant R. Burkhardt ◽  
Scott R. Greene ◽  
Peter White ◽  
Ryan K. Wong ◽  
John E. Brestelli ◽  
...  
Keyword(s):  
Cell Death ◽  
Caspase 3 ◽  
Kinase Inhibitor ◽  
Genetic Networks ◽  
Cyclin Dependent Kinase ◽  
Cyclin Dependent Kinase Inhibitor

scholarly journals Tumor necrosis factor-related apoptosis inducing ligand expression and activity in hen granulosa cells

Reproduction ◽  
2007 ◽  
Vol 133 (3) ◽  
pp. 609-616 ◽  
Author(s):  
A L Johnson ◽  
Christine Ratajczak ◽  
Morgan J Haugen ◽  
Han-Ken Liu ◽  
Dori C Woods
Keyword(s):  
Cell Death ◽  
Tumor Necrosis Factor ◽  
Cell Viability ◽  
Granulosa Cells ◽  
Tumor Necrosis ◽  
Caspase 3 ◽  
Cell Death Pathway ◽  
Wide Range ◽  
Trail Signaling ◽  
Necrosis Factor

Tumor necrosis factor-related apoptosis inducing ligand (TRAIL) represents one of several cytokine members of the tumor necrosis factor superfamily reported to initiate apoptosis in a wide range of transformed, but not most normal, cell types. The present studies were conducted to evaluate the potential for TRAIL to promote apoptotic cell death in differentiated granulosa cells collected from hen preovulatory follicles. While mRNA encoding critical components (including TRAIL) required for a functional extrinsic cell death pathway are expressed in granulosa cells, TRAIL treatment by itself fails to induce either caspase-3 activity or a decrease in cell viability. On the other hand, preculture of cells with the conventional chemotherapeutic, cisplatin, or the 20S proteosome inhibitor, Z-LLF-CHO, sensitizes granulosa cells to TRAIL as evidenced by enhanced caspase-3 activity after 4 h of culture and loss of cell viability after 24 h when compared with either cisplatin or Z-LLF-CHO treatment alone. Moreover, the sensitizing effect of Z-LLF-CHO on TRAIL-induced loss of cell viability is prevented by the selective caspase-8 inhibitor, Z-IETD-FMK. Interestingly, TRAIL mRNA expression is elevated both in prehierarchal follicles undergoing spontaneous atresia and in prehierarchal follicles induced to undergo atresia for 6 h in vitro. In summary, the data demonstrate the presence of a functional TRAIL signaling pathway in hen granulosa cells, and are consistent with the possibility that TRAIL signaling may directly or indirectly participate in the process of follicle atresia in vivo.

PGJ2-stimulated β-cell apoptosis is associated with prolonged UPR activation

2007 ◽  
Vol 292 (4) ◽  
pp. E1052-E1061 ◽  
Author(s):  
Kari T. Chambers ◽  
Sarah M. Weber ◽  
John A. Corbett
Keyword(s):  
Cell Death ◽  
Cell Survival ◽  
Cellular Response ◽  
Caspase 3 ◽  
Initiation Factor ◽  
Cytokine Signaling ◽  
Peroxisome Proliferator ◽  
Β Cells ◽  
Β Cell ◽  
Cell Death Pathway

Peroxisome proliferator-activated receptor-γ (PPARγ) ligands have been shown to possess anti-inflammatory properties that include the inhibition of transcription factor activation and the expression of inflammatory genes. Using pancreatic β-cells, we have shown that PPARγ ligands such as 15-deoxy-Δ12,14-prostaglandin J2 (PGJ2) attenuate interferon-γ-induced signal transducer and activator of transcription 1 activation and interleukin (IL)-1β-induced nuclear factor-κB activation by a pathway that correlates with endoplasmic reticulum stress and the induction of the unfolded protein response (UPR). The UPR is a conserved cellular response activated by a number of cell stressors and is believed to alleviate the stress and promote cell survival. However, prolonged activation of the UPR results in cellular death by apoptosis. In this report, we have examined the effects of PGJ2 on UPR activation and the consequences of this activation on cell survival. Consistent with induction of a cell death pathway, treatment of rat islets and RINm5F cells for 24 h with PGJ2 results in caspase-3 activation and caspase-dependent β-cell death. The actions of these ligands do not appear to be selective for β-cells, because PGJ2 stimulates macrophage apoptosis in a similar fashion. Associated with cell death is the enhanced phosphorylation of eukaryotic initiation factor 2α (eIF2α), and in cells expressing a mutant of eIF2α that cannot be phosphorylated, the stimulatory actions of PGJ2 on caspase-3 activation are augmented. These findings suggest that, whereas PGJ2-induced UPR activation is associated with an inhibition of cytokine signaling, prolonged UPR activation results in cell death, and that eIF2α phosphorylation may function in a protective manner to attenuate cell death.

scholarly journals Fas Induces Cytoplasmic Apoptotic Responses and Activation of the MKK7-JNK/SAPK and MKK6-p38 Pathways Independent of CPP32-like Proteases

1997 ◽  
Vol 139 (4) ◽  
pp. 1005-1015 ◽  
Author(s):  
Fumiko Toyoshima ◽  
Tetsuo Moriguchi ◽  
Eisuke Nishida
Keyword(s):  
Cell Death ◽  
Dna Fragmentation ◽  
Morphological Changes ◽  
Chromatin Condensation ◽  
Cysteine Proteases ◽  
Cellular Responses ◽  
Jurkat Cells ◽  
Mitogen Activated Protein Kinase ◽  
Fas Signaling ◽  
Induced Apoptosis

IL-1β converting enzyme (ICE) family cysteine proteases are subdivided into three groups; ICE-, CPP32-, and Ich-1–like proteases. In Fas-induced apoptosis, activation of ICE-like proteases is followed by activation of CPP32-like proteases which is thought to be essential for execution of the cell death. It was recently reported that two subfamily members of the mitogen-activated protein kinase superfamily, JNK/SAPK and p38, are activated during Fas-induced apoptosis. Here, we have shown that MKK7, but not SEK1/ MKK4, is activated by Fas as an activator for JNK/ SAPK and that MKK6 is a major activator for p38 in Fas signaling. Then, to dissect various cellular responses induced by Fas, we used several peptide inhibitors for ICE family proteases in Fas-treated Jurkat cells and KB cells. While Z-VAD-FK which inhibited almost all the Fas-induced cellular responses blocked the activation of JNK/SAPK and p38, Ac-DEVD-CHO and Z-DEVD-FK, specific inhibitors for CPP32-like proteases, which inhibited the Fas-induced chromatin condensation and DNA fragmentation did not block the activation of JNK/SAPK and p38. Interestingly, these DEVD-type inhibitors did not block the Fas-induced morphological changes (cell shrinkage and surface blebbing), induction of Apo2.7 antigen, or the cell death (as assessed by the dye exclusion ability). These results suggest that the Fas-induced activation of the JNK/SAPK and p38 signaling pathways does not require CPP32-like proteases and that CPP32-like proteases, although essential for apoptotic nuclear events (such as chromatin condensation and DNA fragmentation), are not required for other apoptotic events in the cytoplasm or the cell death itself. Thus, the Fas signaling pathway diverges into multiple, separate processes, each of which may be responsible for part of the apoptotic cellular responses.

Sign in / Sign up

Export Citation Format

Share Document