Evidence of ROS generation by mitochondria in cells with impaired electron transport chain and mitochondrial DNA damage

Mitochondrion ◽  
2007 ◽  
Vol 7 (1-2) ◽  
pp. 106-118 ◽  
Author(s):  
Hiroko P. Indo ◽  
Mercy Davidson ◽  
Hsiu-Chuan Yen ◽  
Shigeaki Suenaga ◽  
Kazuo Tomita ◽  
...  
Keyword(s):  
Dna Damage ◽  
Mitochondrial Dna ◽  
Electron Transport ◽  
Electron Transport Chain ◽  
Ros Generation ◽  
Mitochondrial Dna Damage ◽  
Transport Chain ◽  
In Cells

Abstract 11852: Role of Lox-1 in Mitochondrial Dna Damage and NLRP3 Inflammasome Activation

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Zufeng Ding ◽  
Sadip Pant ◽  
Abhishek Deshmukh ◽  
Jawahar L Mehta
Keyword(s):  
Dna Damage ◽  
Mitochondrial Dna ◽  
Nlrp3 Inflammasome ◽  
Ros Generation ◽  
Inflammasome Activation ◽  
Mtdna Damage ◽  
Mitochondrial Dna Damage ◽  
Mitochondrial Ros ◽  
Nlrp3 Inflammasome Activation

Objective: This study tested the hypothesis that mitochondrial DNA damage could trigger NLRP3 inflammasome activation during inflammation, and LOX-1 may play a critical role in this process. Methods and Results: We performed studies in cultured human THP1 macrophages exposed to ox-LDL or LPS,which are often used as inflammation stimuli in vitro . We examined and confirmed the increase in LOX-1 expression when cells were treated with ox-LDL or LPS. Parallel groups of cells were treated with LOX-1 Ab to bind LOX-1. In accordance with our previous studies in endothelial cells and smooth muscle cells, LOX-1 Ab markedly reduced ox-LDL- as well as LPS-stimulated LOX-1 expression. To assess mitochondrial ROS generation, MitoSOX™ Red mitochondrial superoxide indicator was used. Both fluorescence staining and flow cytometry analysis showed that LPS induced (more than ox-LDL) mitochondrial ROS generation. Pretreatment with LOX-1 Ab significantly attenuated mitochondrial ROS generation in response to ox-LDL or LPS. Then we observed mtDNA damage in THP1 cells exposed to ox-LDL or LPS. Importantly, pretreatment with LOX-1 Ab protected mtDNA from damage in response to both stimuli. This was also confirmed by q-PCR (mtDNA/nDNA ratio) analysis. Further, ox-LDL or LPS induced the expression of phos-NF-kB p65, caspase-1 p10 and p20, and cleaved proteins IL-1β and IL-18. Of note, NLRP3 inflammasome was activated in response to ox-LDL or LPS in a similar manner. Pretreatment of cells with LOX-1 Ab treatment blocked or significantly attenuated these inflammatory responses. Conclusions: These observations based on in vitro observations indicate that LOX-1 via ROS generation plays a key role in mtDNA damage which then leads to NLRP3 inflammasome activation during inflammation.

scholarly journals Farnesol-Induced Generation of Reactive Oxygen Species via Indirect Inhibition of the Mitochondrial Electron Transport Chain in the Yeast Saccharomyces cerevisiae

1998 ◽  
Vol 180 (17) ◽  
pp. 4460-4465 ◽  
Author(s):  
Kiyotaka Machida ◽  
Toshio Tanaka ◽  
Ken-ichi Fujita ◽  
Makoto Taniguchi
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Reactive Oxygen Species ◽  
Electron Transport ◽  
Growth Inhibition ◽  
Electron Transport Chain ◽  
Complex Iii ◽  
Ros Generation ◽  
Oxygen Species ◽  
Mitochondrial Electron Transport Chain ◽  
Transport Chain

ABSTRACT The mechanism of farnesol (FOH)-induced growth inhibition ofSaccharomyces cerevisiae was studied in terms of its promotive effect on generation of reactive oxygen species (ROS). The level of ROS generation in FOH-treated cells increased five- to eightfold upon the initial 30-min incubation, while cells treated with other isoprenoid compounds, like geraniol, geranylgeraniol, and squalene, showed no ROS-generating response. The dependence of FOH-induced growth inhibition on such an oxidative stress was confirmed by the protection against such growth inhibition in the presence of an antioxidant such as α-tocopherol, probucol, orN-acetylcysteine. FOH could accelerate ROS generation only in cells of the wild-type grande strain, not in those of the respiration-deficient petite mutant ([rho 0]), which illustrates the role of the mitochondrial electron transport chain as its origin. Among the respiratory chain inhibitors, ROS generation could be effectively eliminated with myxothiazol, which inhibits oxidation of ubiquinol to the ubisemiquinone radical by the Rieske iron-sulfur center of complex III, but not with antimycin A, an inhibitor of electron transport that is functional in further oxidation of the ubisemiquinone radical to ubiquinone in the Q cycle of complex III. Cellular oxygen consumption was inhibited immediately upon extracellular addition of FOH, whereas FOH and its possible metabolites failed to directly inhibit any oxidase activities detected with the isolated mitochondrial preparation. A protein kinase C (PKC)-dependent mechanism was suggested to exist in the inhibition of mitochondrial electron transport since FOH-induced ROS generation could be effectively eliminated with a membrane-permeable diacylglycerol analog which can activate PKC. The present study supports the idea that FOH inhibits the ability of the electron transport chain to accelerate ROS production via interference with a phosphatidylinositol type of signal.

HIF-1α as a Target for Drug Design in Ischemic Injury: Effect of Cobalt Treatment on Mitochondrial DNA Damage in Cells Exposed to H2O2

2006 ◽  
Vol 3 (3) ◽  
pp. 172-174
Author(s):  
Yasutomo Nomura ◽  
Hiroyuki Fujiwara ◽  
Kohei Ito ◽  
Hirobumi Fuchigami ◽  
Michihiko Sato ◽  
...  
Keyword(s):  
Dna Damage ◽  
Mitochondrial Dna ◽  
Drug Design ◽  
Ischemic Injury ◽  
Mitochondrial Dna Damage ◽  
In Cells

Insulin withdrawal induces apoptosis via a free radical-mediated mechanismThis paper is one of a selection of papers published in this Special Issue, entitled The Cellular and Molecular Basis of Cardiovascular Dysfunction, Dhalla 70th Birthday Tribute.

2007 ◽  
Vol 85 (3-4) ◽  
pp. 455-464 ◽  
Author(s):  
Craig Ricci ◽  
Viktor Pastukh ◽  
Mahmood Mozaffari ◽  
Stephen W. Schaffer
Keyword(s):  
Dna Damage ◽  
Mitochondrial Dna ◽  
Insulin Deficiency ◽  
Neonatal Cardiomyocytes ◽  
Mitochondrial Dna Damage ◽  
Chronic Hyperglycemia ◽  
Transport Chain ◽  
Insulin Withdrawal ◽  
Species Production ◽  
Selection Of

Diabetes is characterized by chronic hyperglycemia as well as insulin deficiency or resistance. However, the majority of research has focused on the consequences of hyperglycemia in development of diabetic complications, whereas the effects of insulin deficiency or resistance, independent of hyperglycemia, have received little attention. Since insulin is a well known cytoprotective factor, we hypothesized that its removal could significantly impact cell survival. To examine this possibility, cultured neonatal cardiomyocytes were subjected to insulin withdrawal and examined for apoptosis. Insulin deficient cells succumbed to apoptosis, an effect associated with impaired PI3-kinase/Akt signaling and reduction in the Bcl-2 to Bax ratio. Perhaps more importantly, superoxide generation was altered in cells subjected to insulin withdrawal. Removal of insulin caused a significant increase in reactive oxygen species production and resulted in oxidative mitochondrial DNA damage the latter effect is associated with impaired expression of mitochondrially encoded proteins that make up the electron transport chain. Significantly, the effects of insulin withdrawal could be mitigated by treatment with the antioxidant, Tiron. Collectively, these data demonstrate that insulin deficiency leads to apoptosis and suggest a role for oxidative mitochondrial DNA damage in this cascade.

scholarly journals Loss of Mcl-1 Protein and Inhibition of Electron Transport Chain Together Induce Anoxic Cell Death

2006 ◽  
Vol 27 (4) ◽  
pp. 1222-1235 ◽  
Author(s):  
Joslyn K. Brunelle ◽  
Emelyn H. Shroff ◽  
Harris Perlman ◽  
Andreas Strasser ◽  
Carlos T. Moraes ◽  
...  
Keyword(s):  
Cell Death ◽  
Mitochondrial Dna ◽  
Electron Transport ◽  
Electron Transport Chain ◽  
Hypoxia Inducible Factor ◽  
Caspase 9 ◽  
Transport Chain ◽  
Base Pair Deletion ◽  
Caspase 2 ◽  
The Individual

ABSTRACT How cells die in the absence of oxygen (anoxia) is not understood. Here we report that cells deficient in Bax and Bak or caspase-9 do not undergo anoxia-induced cell death. However, the caspase-9 null cells do not survive reoxygenation due to the generation of mitochondrial reactive oxygen species. The individual loss of Bim, Bid, Puma, Noxa, Bad, caspase-2, or hypoxia-inducible factor 1β, which are potential upstream regulators of Bax or Bak, did not prevent anoxia-induced cell death. Anoxia triggered the loss of the Mcl-1 protein upstream of Bax/Bak activation. Cells containing a mitochondrial DNA cytochrome b 4-base-pair deletion ([rho −] cells) and cells depleted of their entire mitochondrial DNA ([rho 0] cells) are oxidative phosphorylation incompetent and displayed loss of the Mcl-1 protein under anoxia. [rho 0] cells, in contrast to [rho −] cells, did not die under anoxia. However, [rho 0] cells did undergo cell death in the presence of the Bad BH3 peptide, an inhibitor of Bcl-XL/Bcl-2 proteins. These results indicate that [rho 0] cells survive under anoxia despite the loss of Mcl-1 protein due to residual prosurvival activity of the Bcl-XL/Bcl-2 proteins. Collectively, these results demonstrate that anoxia-induced cell death requires the loss of Mcl-1 protein and inhibition of the electron transport chain to negate Bcl-XL/Bcl-2 proteins.

Sign in / Sign up

Export Citation Format

Share Document