scholarly journals Different Roles of Mitochondria in Cell Death and Inflammation: Focusing on Mitochondrial Quality Control in Ischemic Stroke and Reperfusion

Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 169
Author(s):  
Marianna Carinci ◽  
Bianca Vezzani ◽  
Simone Patergnani ◽  
Peter Ludewig ◽  
Katrin Lessmann ◽  
...  

Mitochondrial dysfunctions are among the main hallmarks of several brain diseases, including ischemic stroke. An insufficient supply of oxygen and glucose in brain cells, primarily neurons, triggers a cascade of events in which mitochondria are the leading characters. Mitochondrial calcium overload, reactive oxygen species (ROS) overproduction, mitochondrial permeability transition pore (mPTP) opening, and damage-associated molecular pattern (DAMP) release place mitochondria in the center of an intricate series of chance interactions. Depending on the degree to which mitochondria are affected, they promote different pathways, ranging from inflammatory response pathways to cell death pathways. In this review, we will explore the principal mitochondrial molecular mechanisms compromised during ischemic and reperfusion injury, and we will delineate potential neuroprotective strategies targeting mitochondrial dysfunction and mitochondrial homeostasis.

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Yue Zhou ◽  
Jun Liao ◽  
Zhigang Mei ◽  
Xun Liu ◽  
Jinwen Ge

Ferroptosis is a nonapoptotic form of cell death characterized by iron-dependent accumulation of lipid hydroperoxides to lethal levels. Necroptosis, an alternative form of programmed necrosis, is regulated by receptor-interacting protein (RIP) 1 activation and by RIP3 and mixed-lineage kinase domain-like (MLKL) phosphorylation. Ferroptosis and necroptosis both play important roles in the pathological progress in ischemic stroke, which is a complex brain disease regulated by several cell death pathways. In the past few years, increasing evidence has suggested that the crosstalk occurs between necroptosis and ferroptosis in ischemic stroke. However, the potential links between ferroptosis and necroptosis in ischemic stroke have not been elucidated yet. Hence, in this review, we overview and analyze the mechanism underlying the crosstalk between necroptosis and ferroptosis in ischemic stroke. And we find that iron overload, one mechanism of ferroptosis, leads to mitochondrial permeability transition pore (MPTP) opening, which aggravates RIP1 phosphorylation and contributes to necroptosis. In addition, heat shock protein 90 (HSP90) induces necroptosis and ferroptosis by promoting RIP1 phosphorylation and suppressing glutathione peroxidase 4 (GPX4) activation. In this work, we try to deliver a new perspective in the exploration of novel therapeutic targets for the treatment of ischemic stroke.


2014 ◽  
Vol 34 (2) ◽  
pp. 179-190 ◽  
Author(s):  
W Zhang ◽  
N Liu ◽  
X Wang ◽  
X Jin ◽  
H Du ◽  
...  

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.


2007 ◽  
Vol 81 (21) ◽  
pp. 12061-12065 ◽  
Author(s):  
Stephanie L. McClain ◽  
Amy J. Clippinger ◽  
Rebecca Lizzano ◽  
Michael J. Bouchard

ABSTRACT The nonstructural hepatitis B virus (HBV) protein HBx has an important role in HBV replication and in HBV-associated liver disease. Many activities have been linked to HBx expression; however, the molecular mechanisms underlying many of these activities are unknown. One proposed HBx function is the regulation of cytosolic calcium. We analyzed calcium levels in HepG2 cells that expressed HBx or replicating HBV, and we demonstrated that HBx, expressed in the absence of other HBV proteins or in the context of HBV replication, elevates cytosolic calcium. We linked this elevation of cytosolic calcium to the association of HBx with the mitochondrial permeability transition pore.


2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Judith Bernal-Ramírez ◽  
Adriana Riojas-Hernández ◽  
Flor E Morales-Marroquín ◽  
Elvía M Domínguez-Barragán ◽  
David Rodríguez-Mier ◽  
...  

Several mechanisms have been implicated in heart failure (HF) development due to obesity, including altered Ca2+ homeostasis and mitochondrial increased reactive oxygen species (ROS). Besides their metabolic role, mitochondria are important cell death regulators, since their disruption induces apoptosis. The mitochondrial permeability transition pore (MPTP) formation is key in this process. Ca2+ and ROS are known inducers of MPTP, and mitochondria are the main ROS generators. However, it has not been demonstrated that MPTP formation is involved in cardiac cell death due to obesity. Therefore, the aim of this work was to determine whether Ca2+ alterations and/or MPTP opening underlie cardiac dysfunction. We used obese Zucker fa/fa rats (32 weeks old), displaying concentric hypertrophy and cardiac dysfunction. We measured: i) Systolic and diastolic Ca2+ signaling in isolated myocytes, in basal conditions and upon β-adrenergic stimulation (β-AS), and ii) in vitro mitochondrial function: respiration, ROS production and MPTP opening. We found that the main alteration in Ca2+ signaling in fa/fa myocytes was a decrease in SERCA Ca2+ removal capacity, since Ca2+ transient amplitude and spark frequency were unchanged. Furthermore, in fa/fa myocytes, β-AS response was preserved. On the other hand, fa/fa mitochondria respiration, in state 3 decreased, but was unchanged in state 4, when glutamate/malate were used as substrate, resulting in an small decrease in respiratory control. In addition, fa/fa mitochondria were more sensitive to MPTP opening, induced by Ca2+ and carboxyatractiloside (CAT). Moreover, fa/fa mitochondria showed increased H2O2 production, and in exposed thiol groups in the adenine nucleotide translocase, a regulatory MPTP component. Since Ca2+ signaling is relatively normal in fa/fa cells, it does not seem to be the main contributor to the cardiac contractile dysfunction. However, given that fa/fa mitochondria showed decrease respiratory performance, were more susceptible to MPTP opening, and showed enhanced H2O2 production. We conclude that fa/fa mitochondria were more vulnerable to enhanced oxidative stress, causing MPTP opening, which could be exacerbated by SERCA slower Ca2+ removal capacity, leading to myocyte apoptosis.


2000 ◽  
Vol 28 (2) ◽  
pp. 170-177 ◽  
Author(s):  
A. P. Halestrap ◽  
E. Doran ◽  
J. P. Gillespie ◽  
A. O'Toole

Mitochondria play a central role in both apoptosis and necrosis through the opening of the mitochondrial permeability transition pore (MPTP). This is thought to be formed through a Ca2+-triggered conformational change of the adenine nucleotide translocase (ANT) bound to matrix cyclophilin-D and we have now demonstrated this directly by reconstitution of the pure components. Opening of the MPTP causes swelling and uncoupling of mitochondria which, unrestrained, leads to necrosis. In ischaemia/reperfusion injury of the heart we have shown MPTP opening directly. Recovery of hearts correlates with subsequent closure, and agents that prevent opening or enhance closure protect from injury. Transient MPTP opening may also be involved in apoptosis by initially causing swelling and rupture of the outer membrane to release cytochrome c (cyt c), which then activates the caspase cascade and sets apoptosis in motion. Subsequent MPTP closure allows ATP levels to be maintained, ensuring that cell death remains apoptotic rather than necrotic. Apoptosis in the hippocampus that occurs after a hypoglycaemic or ischaemic insult is triggered by this means. Other apoptotic stimuli such as cytokines or removal of growth factors also involve mitochondrial cyt c release, but here there is controversy over whether the MPTP is involved. In many cases cyt c release is seen without any mitochondrial depolarization, suggesting that the MPTP does not open. Recent data of our own and others have revealed a specific outer-membrane cyt c-release pathway involving porin that does not release other intermembrane proteins such as adenylate kinase. This is opened by pro-apototic members of the Bcl-2 family such as BAX and prevented by anti-apoptotic members such as Bcl-xL. Our own data suggest that this pathway may interact directly with the ANT in the inner membrane at contact sites.


FEBS Letters ◽  
2001 ◽  
Vol 510 (3) ◽  
pp. 136-140 ◽  
Author(s):  
Elzira E. Saviani ◽  
Cintia H. Orsi ◽  
Jusceley F.P. Oliveira ◽  
Cecı́lia A.F. Pinto-Maglio ◽  
Ione Salgado

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