scholarly journals A lectin from Bothrops leucurus snake venom raises cytosolic calcium levels and promotes B16-F10 melanoma necrotic cell death via mitochondrial permeability transition

Toxicon ◽  
2014 ◽  
Vol 82 ◽  
pp. 97-103 ◽  
Author(s):  
Mary A. Aranda-Souza ◽  
Franco A. Rossato ◽  
Rute A.P. Costa ◽  
Tiago R. Figueira ◽  
Roger F. Castilho ◽  
...  
Keyword(s):  
Cell Death ◽  
Snake Venom ◽  
Mitochondrial Permeability Transition ◽  
Permeability Transition ◽  
Cytosolic Calcium ◽  
Necrotic Cell Death ◽  
Necrotic Cell ◽  
Mitochondrial Permeability

Monocytic cell necrosis is mediated by potassium depletion and caspase-like proteases

1999 ◽  
Vol 276 (3) ◽  
pp. C717-C724 ◽  
Author(s):  
Michel Warny ◽  
Ciarán P. Kelly
Keyword(s):  
Cell Death ◽  
Plasma Membrane ◽  
Mitochondrial Permeability Transition ◽  
Permeability Transition ◽  
Cysteine Proteases ◽  
Morphological Features ◽  
Necrotic Cell Death ◽  
Necrotic Cell ◽  
Monocytic Cell ◽  
Mitochondrial Permeability

Apoptosis is a physiological cell death that culminates in mitochondrial permeability transition and the activation of caspases, a family of cysteine proteases. Necrosis, in contrast, is a pathological cell death characterized by swelling of the cytoplasm and mitochondria and rapid plasma membrane disruption. Necrotic cell death has long been opposed to apoptosis, but it now appears that both pathways involve mitochondrial permeability transition, raising the question of what mediates necrotic cell death. In this study, we investigated mechanisms that promote necrosis induced by various stimuli ( Clostridium difficile toxins, Staphylococcus aureus alpha toxin, ouabain, nigericin) in THP-1 cells, a human monocytic cell line, and in monocytes. All stimuli induced typical features of necrosis and triggered protease-mediated release of interleukin-1β (IL-1β) and CD14 in both cell types. K+depletion was actively implicated in necrosis because substituting K+for Na+in the extracellular medium prevented morphological features of necrosis and IL-1β release. N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone, a broad-spectrum caspase inhibitor, prevented morphological features of necrosis, plasma membrane destruction, loss of mitochondrial membrane potential, IL-1β release, and CD14 shedding induced by all stimuli. Thus, in monocytic cells, necrosis is a cell death pathway mediated by passive K+efflux and activation of caspase-like proteases.

V. Necrapoptosis and the mitochondrial permeability transition: shared pathways to necrosis and apoptosis

1999 ◽  
Vol 276 (1) ◽  
pp. G1-G6 ◽  
Author(s):  
John J. Lemasters
Keyword(s):  
Cell Death ◽  
Mitochondrial Permeability Transition ◽  
Permeability Transition ◽  
Necrotic Cell Death ◽  
Causative Role ◽  
Necrotic Cell ◽  
Mitochondrial Permeability ◽  
Acute Cytotoxicity ◽  
Induced Apoptosis ◽  
Factor Α

Opening of a high-conductance pore conducting solutes of molecular mass <1,500 Da causes onset of the mitochondrial permeability transition (MPT). Cyclosporin A blocks this pore and prevents acute necrotic cell death in several models. Confocal microscopy directly visualizes onset of the MPT during acute cytotoxicity from the movement of the green-fluorescing fluorophore, calcein, into the mitochondria from the cytosol. The MPT also plays a causative role in tumor necrosis factor-α-induced apoptosis in hepatocytes. Progression to apoptosis or necrosis after the MPT may depend on the presence or absence, respectively, of ATP. Often, features of both apoptotic and necrotic cell death develop after death signals and toxic stresses. The term “necrapoptosis” is introduced to emphasize the shared pathways leading to both forms of cell death.

scholarly journals Bax and Bak function as the outer membrane component of the mitochondrial permeability pore in regulating necrotic cell death in mice

eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Jason Karch ◽  
Jennifer Q Kwong ◽  
Adam R Burr ◽  
Michelle A Sargent ◽  
John W Elrod ◽  
...  
Keyword(s):  
Cell Death ◽  
Membrane Permeability ◽  
Outer Membrane ◽  
Mitochondrial Permeability Transition ◽  
Critical Event ◽  
Necrotic Cell Death ◽  
Necrotic Cell ◽  
Inner Membrane ◽  
Mitochondrial Permeability ◽  
Outer Membrane Permeability

A critical event in ischemia-based cell death is the opening of the mitochondrial permeability transition pore (MPTP). However, the molecular identity of the components of the MPTP remains unknown. Here, we determined that the Bcl-2 family members Bax and Bak, which are central regulators of apoptotic cell death, are also required for mitochondrial pore-dependent necrotic cell death by facilitating outer membrane permeability of the MPTP. Loss of Bax/Bak reduced outer mitochondrial membrane permeability and conductance without altering inner membrane MPTP function, resulting in resistance to mitochondrial calcium overload and necrotic cell death. Reconstitution with mutants of Bax that cannot oligomerize and form apoptotic pores, but still enhance outer membrane permeability, permitted MPTP-dependent mitochondrial swelling and restored necrotic cell death. Our data predict that the MPTP is an inner membrane regulated process, although in the absence of Bax/Bak the outer membrane resists swelling and prevents organelle rupture to prevent cell death.

scholarly journals Mitochondrial oxidative stress and cell death in astrocytes —requirement for stored Ca2+ and sustained opening of the permeability transition pore

2002 ◽  
Vol 115 (6) ◽  
pp. 1175-1188 ◽  
Author(s):  
Jake Jacobson ◽  
Michael R. Duchen
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Mitochondrial Permeability Transition ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Ros Generation ◽  
Necrotic Cell Death ◽  
Necrotic Cell ◽  
Mitochondrial Ros ◽  
Transient Events

The role of oxidative stress is established in a range of pathologies. As mitochondria are a major source of reactive oxygen species (ROS), we have developed a model in which an intramitochondrial photosensitising agent is used to explore the consequences of mitochondrial ROS generation for mitochondrial function and cell fate in primary cells. We have found that, in astrocytes, the interplay between mitochondrial ROS and ER sequestered Ca2+ increased the frequency of transient mitochondrial depolarisations and caused mitochondrial Ca2+ loading from ER stores. The depolarisations were attributable to opening of the mitochondrial permeability transition pore (mPTP). Initially, transient events were seen in individual mitochondria, but ultimately, the mitochondrial potential(Δψm) collapsed completely and irreversibly in the whole population. Both ROS and ER Ca2+ were required to initiate these events, but neither alone was sufficient. Remarkably, the transient events alone appeared innocuous, and caused no increase in either apoptotic or necrotic cell death. By contrast, progression to complete collapse ofΔψ m caused necrotic cell death. Thus increased mitochondrial ROS generation initiates a destructive cycle involving Ca2+ release from stores and mitochondrial Ca2+-loading,which further increases ROS production. The amplification of oxidative stress and Ca2+ loading culminates in opening of the mPTP and necrotic cell death in primary brain cells.

Benzo(a)pyrene-7,8-diol-9,10-epoxide induced p53-independent necrosis via the mitochondria-associated pathway involving Bax and Bak activation

2014 ◽  
Vol 34 (2) ◽  
pp. 179-190 ◽  
Author(s):  
W Zhang ◽  
N Liu ◽  
X Wang ◽  
X Jin ◽  
H Du ◽  
...  
Keyword(s):  
Cell Death ◽  
Cytochrome C ◽  
Molecular Mechanisms ◽  
Mitochondrial Permeability Transition Pore ◽  
Mitochondrial Permeability Transition ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Necrotic Cell Death ◽  
Necrotic Cell ◽  
Cytochrome C Release

Benzo(a)pyrene-7,8-diol-9,10-epoxide (BPDE) is a highly reactive DNA damage agent and can induce cell death through both p53-independent and -dependent pathways. However, little is known about the molecular mechanisms of p53-independent pathways in BPDE-induced cell death. To understand the p53-independent mechanisms, we have now examined BPDE-induced cytotoxicity in p53-deficient baby mouse kidney (BMK) cells. The results showed that BPDE could induce Bax and Bak activation, cytochrome c release, caspases activation, and necrotic cell death in the BMK cells. Bax and Bak, two key molecules of mitochondrial permeability transition pore, were interdependently activated by BPDE, with Bax and Bak translocation to and Bax/Bak homo-oligomerization in mitochondria, release of cytochrome c was induced. Importantly, cytochrome c release and necrotic cell death were diminished in BMK cells (Bax−/−), BMK cells (Bak−/−), and BMK cells (Bax−/−/Bak−/−). Furthermore, overexpression of Bcl-2 could ameliorate BPDE-induced cytochrome c release and necrosis. Together the findings suggested that BPDE-induced necrosis was modulated by the p53-independent pathway, which was related to the translocation of Bax and Bak to mitochondria, release of cytochrome c, and activation of caspases.

scholarly journals Metformin induces apoptosis via uterus mitochondrial permeability transition pore opening and protects against estradiol benzoate-induced uterine defect and associated pathophysiological disorder in female Wistar rats

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Adeola Oluwakemi Olowofolahan ◽  
Obinna Matthew Paulinus ◽  
Heritage Mojisola Dare ◽  
Olufunso Olabode Olorunsogo
Keyword(s):  
Cell Death ◽  
Cytochrome C ◽  
Mitochondrial Permeability Transition ◽  
Permeability Transition ◽  
Estradiol Benzoate ◽  
Histological Evaluation ◽  
Mitochondrial Atpase ◽  
Rat Uterus ◽  
Mitochondrial Permeability ◽  
Pore Opening

Abstract Background Some antitumor or anticancer agents have been shown to execute cell death by induction of mitochondrial permeability transition (mPT) pore opening in order to elicit their chemotherapeutic effect. Therefore, this study investigated the effect of metformin on cell death via rat uterus mPT pore and estradiol benzoate-induced uterine defect and associated pathophysiological disorder in female rat. Mitochondria were isolated using differential centrifugation. The mPT pore opening, cytochrome c release and mitochondrial ATPase activity were determined spectrophotometrically. Caspases 9 and 3 activities, MDA and estradiol levels and SOD, GSH activities, were determined using ELISA technique. Histological and histochemical assessments of the uterine section were carried out using standard methods. Results Metformin at concentrations 10–90 μg/mL, showed no significant effect on mPT pore opening, mATPase activity and release of cytochrome c. However, oral administration of metformin caused mPT pore opening, enhancement of mATPase activity and activation of caspases 9 and 3 significantly at 300 and 400 mg/kg. Metformin protected against estradiol benzoate (EB)-induced uterine defect and other associated pathophysiological disorder. It also improved the antioxidant defense system. The histological evaluation revealed the protective effect of metformin on the cellular architecture of the uterus while the histochemical examination showed severe hyperplasia in the uterine section of EB-treated rats, remarkably reversed by metformin co-treatment. Conclusion This study suggests that metformin at high doses induces apoptosis via rat uterus mPT pore opening and protects against EB-induced uterine defect (hyperplasia) and associated pathophysiological disorder.

Sign in / Sign up

Export Citation Format

Share Document