scholarly journals Role of Mitochondrial Calcium and the Permeability Transition Pore in Regulating Cell Death

2020 ◽  
Vol 126 (2) ◽  
pp. 280-293 ◽  
Author(s):  
Tyler M. Bauer ◽  
Elizabeth Murphy
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Reactive Oxygen ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Mitochondrial Calcium ◽  
Oxygen Species ◽  
Inner Mitochondrial Membrane ◽  
Atp Production ◽  
Cell Death Pathways

Adult cardiomyocytes are postmitotic cells that undergo very limited cell division. Thus, cardiomyocyte death as occurs during myocardial infarction has very detrimental consequences for the heart. Mitochondria have emerged as an important regulator of cardiovascular health and disease. Mitochondria are well established as bioenergetic hubs for generating ATP but have also been shown to regulate cell death pathways. Indeed many of the same signals used to regulate metabolism and ATP production, such as calcium and reactive oxygen species, are also key regulators of mitochondrial cell death pathways. It is widely hypothesized that an increase in calcium and reactive oxygen species activate a large conductance channel in the inner mitochondrial membrane known as the PTP (permeability transition pore) and that opening of this pore leads to necroptosis, a regulated form of necrotic cell death. Strategies to reduce PTP opening either by inhibition of PTP or inhibiting the rise in mitochondrial calcium or reactive oxygen species that activate PTP have been proposed. A major limitation of inhibiting the PTP is the lack of knowledge about the identity of the protein(s) that form the PTP and how they are activated by calcium and reactive oxygen species. This review will critically evaluate the candidates for the pore-forming unit of the PTP and discuss recent data suggesting that assumption that the PTP is formed by a single molecular identity may need to be reconsidered.

scholarly journals OTUD1 deubiquitylase regulates NF-κB- and KEAP1-mediated inflammatory responses and reactive oxygen species-associated cell death pathways

2021 ◽  
Author(s):  
Daisuke Oikawa ◽  
Min Gi ◽  
Hidetaka Kosako ◽  
Kouhei Shimizu ◽  
Hirotaka Takahashi ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Stress Responses ◽  
Inflammatory Responses ◽  
Reactive Oxygen ◽  
Antioxidant Response ◽  
Oxygen Species ◽  
Ubiquitin Chain ◽  
Intrinsically Disordered ◽  
Cell Death Pathways

Deubiquitylating enzymes (DUBs) regulate numerous cellular functions by removing ubiquitin modifications. We examined the effects of 88 human DUBs on linear ubiquitin chain assembly complex (LUBAC)-induced NF-κB activation, and identified OTUD1 as a potent suppressor. OTUD1 regulates the canonical NF-κB pathway by hydrolysing K63-linked ubiquitin chains from NF-κB signalling factors, including LUBAC. OTUD1 negatively regulates the canonical NF-κB activation, apoptosis, and necroptosis, whereas OTUD1 upregulates the interferon (IFN) antiviral pathway. The N-terminal intrinsically disordered region of OTUD1, which contains an EGTE motif, is indispensable for KEAP1-binding and NF-κB suppression. OTUD1 is involved in the KEAP1-mediated antioxidant response and reactive oxygen species (ROS)-induced cell death, oxeiptosis. In Otud1-/--mice, inflammation, oxidative damage, and cell death were enhanced in inflammatory bowel disease, acute hepatitis, and sepsis models. Thus, OTUD1 is a crucial regulator for the inflammatory, innate immune, and oxidative stress responses and ROS-associated cell death pathways.

Apoptosis in Heart and Skeletal Muscle

2002 ◽  
Vol 27 (4) ◽  
pp. 349-395 ◽  
Author(s):  
Andy J. Primeau ◽  
Peter J. Adhihetty ◽  
David A. Hood
Keyword(s):  
Reactive Oxygen Species ◽  
Skeletal Muscle ◽  
Cell Death ◽  
Mitochondrial Permeability Transition ◽  
Ischemia Reperfusion ◽  
Reactive Oxygen ◽  
Permeability Transition ◽  
Current Evidence ◽  
Oxygen Species ◽  
Cellular Mechanisms

Apoptosis, or programmed cell death, is now recognized to be an important cellular event during normal development and in the progression of specific diseases. Apoptosis can be triggered by stimuli initiating outside of the cell, or within the mitochondria, leading to the activation of caspases and subsequent cell death. Although apoptosis has been widely studied in a variety of tissues over the last 5 years, skeletal muscle and heart have been relatively ignored in this regard. Research on apoptosis in cardiac muscle has recently taken on a higher profile as the recognition emerges that it may be an important contributor to specific cardiac pathologies, particularly in response to ischemia-reperfusion in which reactive oxygen species are formed. In skeletal muscle, very few studies have been done under specific physiological (e.g., exercise) and pathophysiological (e.g., dystrophies, denervation, myopathies) conditions. Skeletal muscle is unique in that it is mutli-nucleated, and evidence suggests that it can undergo individual myonuclear apoptosis as well as complete cell death. This review discusses the basic cellular mechanisms of apoptosis, as well as the current evidence of this process in cardiac and skeletal muscle. The need for more work in this area is highlighted, particularly in exercise and training. Key words: transcription factors, reactive oxygen species, mitochondria, caspase, mitochondrial permeability transition

scholarly journals The pH Hypothesis of Postconditioning

Circulation ◽  
2007 ◽  
Vol 115 (14) ◽  
pp. 1895-1903 ◽  
Author(s):  
Michael V. Cohen ◽  
Xi-Ming Yang ◽  
James M. Downey
Keyword(s):  
Reactive Oxygen Species ◽  
Mitochondrial Permeability Transition ◽  
Reactive Oxygen ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Oxygen Species ◽  
Risk Zone ◽  
Kinase C ◽  
Protective Signaling ◽  
Reactive Oxygen Species Scavenger

Background— It is unclear how reperfusion of infarcting hearts with alternating cycles of coronary reperfusion/occlusion attenuates infarction, but prevention of mitochondrial permeability transition pore (MPTP) formation is crucial. Acidosis also suppresses MPTP formation. We tested whether postconditioning protects by maintaining acidosis during early reoxygenation. Methods and Results— After 30-minute regional ischemia in isolated rabbit hearts, reperfusion with buffer (pH 7.4) caused 34.4±2.2% of the risk zone to infarct, whereas 2 minutes of postconditioning (6 cycles of 10-second reperfusion/10-second occlusion) at reperfusion resulted in 10.7±2.9% infarction. One minute (3 cycles) of postconditioning was not protective. Hypercapnic buffer (pH 6.9) for the first 2 minutes of reperfusion in lieu of postconditioning caused equivalent cardioprotection (15.0±2.6% infarction), whereas 1 minute of acidosis did not protect. Delaying postconditioning (6 cycles) or 2 minutes of acidosis for 1 minute aborted protection. Reperfusion with buffer (pH 7.7) blocked postconditioning protection, but addition of the MPTP closer cyclosporin A restored protection. Reactive oxygen species scavenger N-2-mercaptopropionyl glycine, protein kinase C antagonist chelerythrine, and mitochondrial K ATP channel closer 5-hydroxydecanoate each blocked protection from 2 minutes of acidosis as they did for postconditioning. Conclusion— Thus, postconditioning prevents MPTP formation by maintaining acidosis during the first minutes of reperfusion as reoxygenated myocardium produces reactive oxygen species that activate protective signaling to inhibit MPTP formation after pH normalization.

Holographic monitoring of cell death pathways induced by reactive oxygen species

2018 ◽  
Author(s):  
A.V. Belashov ◽  
A.A. Zhikhoreva ◽  
D.A. Rogova ◽  
T.N. Belyaeva ◽  
E.S. Kornilova ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Cell Death Pathways
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