scholarly journals Overexpression of catalase in mitochondria mitigates changes in hippocampal cytokine expression following simulated microgravity and isolation

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Linda Rubinstein ◽  
Ann-Sofie Schreurs ◽  
Samantha M. Torres ◽  
Sonette Steczina ◽  
Moniece G. Lowe ◽  
...  

AbstractIsolation on Earth can alter physiology and signaling of organs systems, including the central nervous system. Although not in complete solitude, astronauts operate in an isolated environment during spaceflight. In this study, we determined the effects of isolation and simulated microgravity solely or combined, on the inflammatory cytokine milieu of the hippocampus. Adult female wild-type mice underwent simulated microgravity by hindlimb unloading for 30 days in single or social (paired) housing. In hippocampus, simulated microgravity and isolation each regulate a discrete repertoire of cytokines associated with inflammation. Their combined effects are not additive. A model for mitochondrial reactive oxygen species (ROS) quenching via targeted overexpression of the human catalase gene to the mitochondria (MCAT mice), are protected from isolation- and/or simulated microgravity-induced changes in cytokine expression. These findings suggest a key role for mitochondrial ROS signaling in neuroinflammatory responses to spaceflight and prolonged bedrest, isolation, and confinement on Earth.

2020 ◽  
Vol 129 (1) ◽  
pp. 124-132 ◽  
Author(s):  
Hiroaki Eshima ◽  
Piyarat Siripoksup ◽  
Ziad S. Mahmassani ◽  
Jordan M. Johnson ◽  
Patrick J. Ferrara ◽  
...  

The premise of this study was to examine the efficacy of genetic suppression of mitochondrial reactive oxygen species (ROS) to attenuate disuse-induced muscle atrophy and muscle weakness. Neutralization of mitochondrial ROS by MCAT expression was insufficient to rescue muscle atrophy and muscle weakness.


Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 150
Author(s):  
Kimberly J. Nelson ◽  
Terri Messier ◽  
Stephanie Milczarek ◽  
Alexis Saaman ◽  
Stacie Beuschel ◽  
...  

A central hallmark of tumorigenesis is metabolic alterations that increase mitochondrial reactive oxygen species (mROS). In response, cancer cells upregulate their antioxidant capacity and redox-responsive signaling pathways. A promising chemotherapeutic approach is to increase ROS to levels incompatible with tumor cell survival. Mitochondrial peroxiredoxin 3 (PRX3) plays a significant role in detoxifying hydrogen peroxide (H2O2). PRX3 is a molecular target of thiostrepton (TS), a natural product and FDA-approved antibiotic. TS inactivates PRX3 by covalently adducting its two catalytic cysteine residues and crosslinking the homodimer. Using cellular models of malignant mesothelioma, we show here that PRX3 expression and mROS levels in cells correlate with sensitivity to TS and that TS reacts selectively with PRX3 relative to other PRX isoforms. Using recombinant PRXs 1–5, we demonstrate that TS preferentially reacts with a reduced thiolate in the PRX3 dimer at mitochondrial pH. We also show that partially oxidized PRX3 fully dissociates to dimers, while partially oxidized PRX1 and PRX2 remain largely decameric. The ability of TS to react with engineered dimers of PRX1 and PRX2 at mitochondrial pH, but inefficiently with wild-type decameric protein at cytoplasmic pH, supports a novel mechanism of action and explains the specificity of TS for PRX3. Thus, the unique structure and propensity of PRX3 to form dimers contribute to its increased sensitivity to TS-mediated inactivation, making PRX3 a promising target for prooxidant cancer therapy.


2005 ◽  
Vol 25 (19) ◽  
pp. 8520-8530 ◽  
Author(s):  
Peter Storz ◽  
Heike Döppler ◽  
Alex Toker

ABSTRACT Efficient elimination of mitochondrial reactive oxygen species (mROS) correlates with increased cellular survival and organism life span. Detoxification of mitochondrial ROS is regulated by induction of the nuclear SOD2 gene, which encodes the manganese-dependent superoxide dismutase (MnSOD). However, the mechanisms by which mitochondrial oxidative stress activates cellular signaling pathways leading to induction of nuclear genes are not known. Here we demonstrate that release of mROS activates a signal relay pathway in which the serine/threonine protein kinase D (PKD) activates the NF-κB transcription factor, leading to induction of SOD2. Conversely, the FOXO3a transcription factor is dispensable for mROS-induced SOD2 induction. PKD-mediated MnSOD expression promotes increased survival of cells upon release of mROS, suggesting that mitochondrion-to-nucleus signaling is necessary for efficient detoxification mechanisms and cellular viability.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Xian-Long Zhou ◽  
Xiao-Jun Wei ◽  
Shao-Ping Li ◽  
Rui-Ning Liu ◽  
Ming-Xia Yu ◽  
...  

Cytosolic phospholipase A2 (cPLA2) has been reported to be critical for infection-induced mitochondrial reactive oxygen species (ROS) production and diaphragm dysfunction (DD). In the present study, we aim to investigate whether cPLA2 was involved in ventilator-induced diaphragm dysfunction (VIDD). Our results showed that mechanical ventilation (MV) induced cPLA2 activation in the diaphragm with excessive mitochondrial ROS generation and muscle weakness. Specific inhibition of cPLA2 with CDIBA resulted in decreased mitochondrial ROS levels and improved diaphragm forces. In addition, mitochondria-targeted antioxidant MitoTEMPO attenuated ventilator-induced mitochondrial oxidative stress and downregulated cPLA2 activation in vivo. Both CDIBA and MitoTEMPO were able to attenuate protein degradation, muscle atrophy, and weakness following prolonged MV. Furthermore, laser Doppler imaging showed that MV decreased diaphragm tissue perfusion and induced subsequent hypoxia. An in vitro study also demonstrated a positive association between cPLA2 activation and mitochondrial ROS generation in C2C12 cells cultured under hypoxic condition. Collectively, our study showed that cPLA2 activation positively interacts with mitochondrial ROS generation in the development of VIDD, and ventilator-induced diaphragm hypoxia serves as a possible contributor to this positive feedback loop.


2021 ◽  
Author(s):  
Patrick Pagesy ◽  
Abdelouhab Bouaboud ◽  
Zhihao Feng ◽  
Philippe Hulin ◽  
Tarik Issad

O-GlcNAcylation is a reversible post-translational modification involved the regulation of cytosolic, nuclear and mitochondrial proteins. Only two enzymes, OGT and OGA, control attachment and removal of O-GlcNAc on proteins, respectively. Whereas a variant OGT (mOGT) has been proposed as the main isoform that O-GlcNAcylates proteins in mitochondria, identification of a mitochondrial OGA has not been performed yet. Two splice variants of OGA (short and long isoforms) have been described previously. In this work, using cell fractionation experiments, we show that short-OGA is preferentially recovered in mitochondria-enriched fractions from HEK-293T cells as well as mouse embryonic fibroblasts. Moreover, fluorescent microscopy imaging confirmed that GFP-tagged short-OGA is addressed to mitochondria. In addition, using a BRET-based mitochondrial O-GlcNAcylation biosensor, we show that co-transfection of short-OGA markedly reduced O-GlcNAcylation of the biosensor, whereas long-OGA had no significant effect. Finally, using genetically encoded or chemical fluorescent mitochondrial probes, we showed that short-OGA overexpression increases mitochondrial ROS levels, whereas long-OGA had no significant effect. Together, our work reveals that the short-OGA isoform is targeted to the mitochondria where it regulates ROS homoeostasis.


2018 ◽  
Vol 9 (7) ◽  
pp. 3895-3905 ◽  
Author(s):  
Minna Shin ◽  
Bo-Mi Lee ◽  
Okwha Kim ◽  
Huynh Nguyen Khanh Tran ◽  
Suhyun Lee ◽  
...  

Coumaroyl alphitolic acids induce apoptotic cell death in cancer cellsviamitochondrial ROS production and ER stress.


2020 ◽  
Author(s):  
Chris Ugbode ◽  
Nathan Garnham ◽  
Laura Fort-Aznar ◽  
Gareth Evans ◽  
Sangeeta Chawla ◽  
...  

AbstractReactive oxygen species (ROS) are generated during physiological bouts of synaptic activity and as a consequence of pathological conditions in the central nervous system. How neurons respond to and distinguish between ROS in these different contexts is currently unknown. In Drosophila mutants with enhanced JNK activity, lower levels of ROS are observed and these animals are resistant to both changes in ROS and changes in synapse morphology induced by oxidative stress. In wild type flies, disrupting JNK-AP-1 signalling perturbs redox homeostasis suggesting JNK activity positively regulates neuronal antioxidant defense. We validated this hypothesis in mammalian neurons, finding that JNK activity regulates the expression of the antioxidant gene Srxn-1, in a c-Jun dependent manner. We describe a conserved ‘adaptive’ role for neuronal JNK in the maintenance of redox homeostasis that is relevant to several neurodegenerative diseases.


2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Sumitra Miriyala ◽  
Mini Chandra ◽  
Jonathan Fox ◽  
Christopher Kevil ◽  
Wayne Orr ◽  
...  

Constitutive activation mitochondrial reactive oxygen species (ROS) has been implicated in both the pathogenesis and the progression of cardiovascular disease. Absence of SOD2 (gene that encodes MnSOD) is found to be embryonic lethal in animal models due to impairment of mitochondrial function, most noticeably in the heart. In our earlier investigation, we have shown that the MnSOD mimetic, distributes 3-fold more in mitochondria than in cytosol. The exceptional ability of MnSOD mimetic to dismute O 2 •- parallels its ability to reduce ONOO– and CO3–. Based on our earlier reports, we have generated mice that specifically lack MnSOD in cardiomyocytes (Mhy6-SOD2 Δ ). These mice showed early mortality ~4 months due to cardiac mitochondrial dysfunction. Oxidative phosphorylation (OXPHOS) in mitochondria is the predominant mode for O 2 consumption in cells, and the mitochondria are the primary source of ROS in cells due to leaked electrons. FACS analyses using Mito-Tracker Green indicated that the mass of mitochondria per cell was slightly decreased in the Mhy6-SOD2 Δ to the wild type. The rate of oxygen consumption per cells was significantly lower in Mhy6-SOD2 Δ cardiomyocytes than that in wild type. The most noticeable difference in the O 2 consumption was found in the presence of FCCP (H+ ionophore / uncoupler). Remarkably, while the FCCP treatment increased O 2 consumption in wild type, the treatment showed no effect on the O 2 consumption in the Mhy6-SOD2 Δ cardiomyocytes. The result indicated that the low basal OXPHOS activity in Mhy6-SOD2 Δ was due to unusually low OXPHOS potential.


2021 ◽  
Vol 11 ◽  
Author(s):  
Editorial Office ROS

In addition to the diverse well-known physiological functions and pathophysiological effects of sodium ion (Na⁺), regulation of mitochondrial reactive oxygen species (ROS) by Na⁺ has recently been demonstrated by several studies published in highly influential journals. The findings from these studies, especially the proposed “cytosolic Na⁺‒Na⁺/Ca²⁺ exchanger‒mitochondrial ROS” axis, have greatly broadened our understanding of this most popular element in physiology and disease. REFERENCES Kohlhaas M, Liu T, Knopp A, Zeller T, Ong MF, Bohm M, et al. Elevated cytosolic Na+ increases mitochondrial formation of reactive oxygen species in failing cardiac myocytes. Circulation 2010; 121(14):1606-13. doi: https://dx.doi.org/10.1161/CIRCULATIONAHA.109.914911. Dey S, DeMazumder D, Sidor A, Foster DB, O'Rourke B. Mitochondrial ROS drive sudden cardiac death and chronic proteome remodeling in heart failure. Circ Res 2018; 123(3):356-71. doi: https://dx.doi.org/10.1161/CIRCRESAHA.118.312708. Murphy E, Eisner DA. Regulation of intracellular and mitochondrial sodium in health and disease. Circ Res 2009; 104(3):292-303. doi: https://dx.doi.org/10.1161/CIRCRESAHA.108.189050. Adrogue HJ, Madias NE. Sodium and potassium in the pathogenesis of hypertension. N Engl J Med 2007; 356(19):1966-78. doi: https://dx.doi.org/10.1056/NEJMra064486. Hernansanz-Agustin P, Choya-Foces C, Carregal-Romero S, Ramos E, Oliva T, Villa-Pina T, et al. Na+ controls hypoxic signalling by the mitochondrial respiratory chain. Nature 2020; 586(7828):287-91. doi: https://dx.doi.org/10.1038/s41586-020-2551-y. Wolf SG, Mutsafi Y, Dadosh T, Ilani T, Lansky Z, Horowitz B, et al. 3D visualization of mitochondrial solid-phase calcium stores in whole cells. Elife 2017; 6. doi: https://dx.doi.org/10.7554/eLife.29929. Shadel GS, Horvath TL. Mitochondrial ROS signaling in organismal homeostasis. Cell 2015; 163(3):560-9. doi: https://dx.doi.org/10.1016/j.cell.2015.10.001. Oberkampf M, Guillerey C, Mouries J, Rosenbaum P, Fayolle C, Bobard A, et al. Mitochondrial reactive oxygen species regulate the induction of CD8+ T cells by plasmacytoid dendritic cells. Nat Commun 2018; 9(1):2241. doi: https://dx.doi.org/10.1038/s41467-018-04686-8. Sena LA, Li S, Jairaman A, Prakriya M, Ezponda T, Hildeman DA, et al. Mitochondria are required for antigen-specific T cell activation through reactive oxygen species signaling. Immunity 2013; 38(2):225-36. doi: https://dx.doi.org/10.1016/j.immuni.2012.10.020.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Vlad G Zaha ◽  
Dake Qi ◽  
Hui-Young Lee ◽  
Xiaoyue Hu ◽  
Xiaohong Wu ◽  
...  

AMP-activated kinase (AMPK) is a key stress responsive kinase that regulates cellular adaptation to metabolic stress. Inactivation of AMPK in “kinase-dead” (KD) mice increases myocardial damage following ischemia-reperfusion (IR). We have also shown decreased mitochondrial respiration and increased mitochondrial reactive oxygen species (ROS) production and susceptibility to mitochondrial transition pore opening in KD hearts following IR. The aim of this study was to establish the importance of mitochondrial ROS production and downstream deleterious signaling to mediate tissue damage in absence of active AMPK in the heart. Detoxification of mitochondrial ROS requires conversion of hydrogen peroxide to water, therefore, we studied the effect of transgenic expression of mitochondrial catalase (MCAT) in wild type (WT) and KD mice. MCAT prevents mitochondrial hydrogen peroxide production independent of mitochondrial energy production. Myocardial necrosis was assessed in vitro after global ischemia-reperfusion and in vivo after LAD ligation and reperfusion. Mitogen activated protein kinase kinase 4 (MKK4) and downstream c-Jun terminal kinase (JNK) expression and phosphorylation was assessed in vivo. Increased necrosis in KD hearts following mild global ischemia (15 minutes) - reperfusion (10 minutes) in vitro, was prevented by expression of MCAT (WT vs. KD 17.8±4.1 vs. 50±4.1%, p<0.05 and MCAT-WT vs. MCAT-KD 16.9±4.8 vs. 29.3±4.4%, n.s., and factorial p<0.05). Total JNK protein was not increased in WT and KD hearts with or without expression of MCAT. After coronary occlusion in vivo, KD mice showed increased cardiac activation of MKK4/JNK pathway (p<0.05) as well as greater myocardial necrosis (p<0.05). MCAT expression prevented the excessive cardiac JNK activation observed during IR in KD mice in vivo. Inhibition of JNK with SP600125 (10μM) during in vivo IR also resulted in a significant decrease in necrosis in KD hearts (WT vs. KD 9.1±0.7 vs. 28.2±2.9%, p<0.05 and WT vs. KD with SP600125 8.5±0.5 vs. 10.2±1.1%, n.s. and factorial p<0.05, percentage of equivalent area at risk). Thus, AMPK activation during IR prevents excess mitochondrial reactive oxygen production and consequent JNK signaling, thus protecting against myocardial injury.


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