Abstract 210: Thioredoxin-2 Inhibits Mitochondrial Ros Generation And Ask1 Activity To Maintain Cardiac Function

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Wang Min ◽  
Qunhua Huang
Keyword(s):  
Heart Failure ◽  
Cardiac Function ◽  
Dilated Cardiomyopathy ◽  
Mitochondrial Dysfunction ◽  
Ros Generation ◽  
Contractile Dysfunction ◽  
Ros Production ◽  
Atp Production ◽  
Mitochondrial Ros ◽  
Cellular Apoptosis

Background: Increasing evidence indicates that mitochondrial-derived reactive oxygen species (ROS) and cellular apoptosis contribute to the pathogenesis of cardiac dysfunction. Mitochondrial thioredoxin (Trx2) is a key protein regulating cellular redox and survival, However, but its role in normal cardiac growth has not been determined. Methods and Results: We have generated cardiac-specific Trx2 knockout mice (Trx2-cKO) to determine the physiological importance of the Trx2 system in the heart. Trx2-cKO mice developed a spontaneous dilated cardiomyopathy at 1 month of age with increased heart size, fibrosis, reduced ventricular wall thickness, and progressive contractile dysfunction, resulting in death due to heart failure by 4 months of age. Cardiac changes in Trx2-cKO mice were accompanied by disruption of mitochondrial integrity and function, as evident by alterations in mitochondrial number, ultrastructure, membrane potential and ATP production. Increases in ASK1 signaling and ROS production preceded mitochondrial damage, cellular apoptosis and contractile dysfunction in both Trx2-cKO hearts and isolated cardiomyocytes. Moreover, deletion of ASK1 attenuates ROS production, mitochondrial dysfunction and cellular apoptosis in Trx2-deficient cardiomyocytes. These data indicate that ASK1 is a major target of Trx2 and that activation of ASK1 is causally associated with mitochondrial dysfunction, ROS production and cellular apoptosis. We also detected reduced Trx2 expression and increased ASK1 activity in human hearts from patients with cardiomyopathy, suggesting that this mechanism is clinically important. Conclusion: Our data support an essential role for mitochondrial Trx2 in preserving cardiac function by suppressing mitochondrial ROS production and ASK1-dependent apoptosis. These results suggest that pharmacological inhibition of ASK1 may provide a therapeutic strategy for the treatment of dilated cardiomyopathy and heart failure.

Abstract 403: FAM210A Maintains Cardiac Mitochondrial Homeostasis Through Regulating Letm1-dependent Ca 2+ Efflux

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Jiangbin Wu ◽  
Chinna Venkata ◽  
Si Chen ◽  
Omar Hedaya ◽  
Chen Yan ◽  
...  
Keyword(s):  
Heart Failure ◽  
Membrane Potential ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Respiratory Activity ◽  
Genome Wide Association Studies ◽  
Ros Production ◽  
Mitochondrial Homeostasis ◽  
Mitochondrial Ros

Mitochondria play fundamental roles in supporting healthy myocardium function. Disturbed cardiac mitochondrial homeostasis causes mitochondrial dysfunction associated with cardiomyopathy in humans and mice. Recent genome-wide association studies (GWAS) discovered that the mutations of FAM210A (family with sequence similarity 210 member A) are associated with sarcopenia and osteoporosis. Interestingly, Fam210a is most highly expressed in the heart and multiple omics analyses in mouse hearts reveal Fam210a as a hub gene in cardiac hypertrophy. However, the molecular function of FAM210A in the heart remains elusive. Here, we discover that FAM210A is critical for maintaining cardiac mitochondrial function and homeostasis. Cardiomyocyte (CM) specific knockout (KO) of Fam210a in adult mice leads to progressive heart failure with enlarged left ventricle chamber and ultimately causes mortality at ~70 days after Fam210a KO. The FAM210A deficient CMs exhibit myofilament disarray at ~9 weeks post Fam210a KO. Moreover, Fam210a KO results in a remarkably elevated mitochondrial ROS production, dramatically compromised mitochondrial membrane potential, and reduced expression of mitochondrial electron transport chain (ETC) complex genes. As a result, the mitochondrial respiratory activity is significantly reduced and the mitochondrial cristae are disrupted in Fam210a KO CMs. In contrast, at the early stage of ~5 weeks post tamoxifen-induced Fam210a KO, we observe increased mitochondrial ROS production, disturbed mitochondrial membrane potential, and reduced respiratory activity in CMs prior to heart failure. Transcriptomic and proteomic analyses from Fam210a KO hearts indicate that FAM210A deficiency causes chronic integrated stress response (ISR) in the heart. Mechanistically, Interactome analyses show that FAM210A binds to mitochondrial Ca 2+ /H + exchanger LETM1 (leucine zipper and EF-hand containing transmembrane protein 1) and regulates LETM1-mediated mitochondrial Ca 2+ efflux. Altogether, we discover a novel function of FAM210A in maintaining the cardiac mitochondrial homeostasis by regulating mitochondrial Ca 2+ efflux, and deficiency of FAM210A causes mitochondrial dysfunction and leads to heart failure.

scholarly journals Mechanical Ventilation Preserves Diaphragm Mitochondrial Function in a Rat Sepsis Model

2020 ◽  
Author(s):  
Pierre Eyenga ◽  
Damien Roussel ◽  
Benjamin Rey ◽  
Patrice Ndille ◽  
Loic Teulier ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Oxygen Consumption ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Oxidase Activity ◽  
Ros Generation ◽  
Mitochondrial Oxygen Consumption ◽  
Atp Production ◽  
Mitochondrial Ros ◽  
Mda Content

Abstract Background: To describe the effect of mechanical ventilation on diaphragm mitochondrial oxygen consumption, ATP production, reactive oxygen species (ROS) generation, and cytochrome-c oxidase activity and content, and their relationship to diaphragm strength in an experimental model of sepsis.Methods: A cecal ligation and puncture (CLP) protocol was performed in 12 rats while 12 controls underwent sham-operation. Half of the rats in each group were paralyzed and mechanically ventilated. We performed blood gas analysis and lactic acid assays 6 hours after surgery. Afterwards, we measured diaphragm strength and mitochondrial oxygen consumption, ATP and ROS generation, and cytochrome-c oxidase activity. We also measured malondialdehyde (MDA) content as an index of lipid peroxidation, and mRNA expression of the pro-inflammatory interleukin-1β (IL-1β) in diaphragms.Results: CLP rats showed severe hypotension, metabolic acidosis, and upregulation of diaphragm IL-1β mRNA expression. Compared to sham controls, spontaneously breathing CLP rats showed lower diaphragm force and increased susceptibility to fatigue, along with depressed mitochondrial oxygen consumption and ATP production and cytochrome-c oxidase activity. These rats also showed increased mitochondrial ROS generation and MDA content. Mechanical ventilation markedly restored mitochondrial oxygen consumption and ATP production in CLP rats; lowered mitochondrial ROS production by the complex 3; and preserved cytochrome-c oxidase activity.Conclusion: In an experimental model of sepsis, early initiation of mechanical ventilation restores diaphragm mitochondrial function.

Abstract P241: Calpain-1 Is Increased in Mitochondria and Contributes to Mitochondrial ROS Generation in High Glucose--Stimulated Endothelial Cells and Endothelial Dysfunction in Mouse Models of Diabetes

2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Qing Zhao ◽  
Futian Tang ◽  
Limei Shan ◽  
Inga Cepinskas ◽  
Gedas Cepinskas ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
High Glucose ◽  
Aortic Ring ◽  
Ros Generation ◽  
Type I ◽  
Ros Production ◽  
Diabetic Mice ◽  
Calpain Activity ◽  
Over Expression ◽  
Mitochondrial Ros

Objectives: Elevated levels of reactive oxygen species (ROS) are the initial source of endothelial dysfunction in diabetes. Calpain has been implicated in diabetic vascular complications. The present study was to investigate the role of calpain in mitochondrial ROS generation in endothelial cells and vascular dysfunction in diabetic mice. Methods: Endothelial cells cultured from human umbilical vein (HUVEC) were stimulated with high glucose. Calpain activity and protein were determined in mitochondria of HUVEC. Intracellular and mitochondrial ROS generation as well as apoptosis were measured. Type I diabetic OVE 26 mice and type II diabetic db/db mice with calpastatin over-expression (OVE26/CAST and db/db-CAST) were generated, respectively. Type I diabetes was also induced in both wild-type and Tg-CAST mice by injection of streptozocin (STZ). The endothelium-dependent relaxation of aortic ring was measured. Results: High glucose significantly increased calpain-1 protein, calpain activity and ROS generation in mitochondria of HUVEC. Pharmacological inhibition of calpain or over-expression of calpastatin abrogated high glucose-induced intracellular ROS production, mitochondrial ROS generation and apoptosis in HUVEC. Incubation of isolated mitochondria with calpain-1 protein significantly induced its ROS generation and the membrane potential. In diabetic mice, calpain activity was induced in aortic vessels, which correlated with an increase in ROS production and protein tyrosine nitration. Over-expression of calpastatin prevented calpain activity, reduced ROS production and inhibited protein tyrosine nitration in diabetic mice. Aortic ring segments from diabetic mice exhibited a significant reduction in vascular relaxation to acetylcholine, which was reversed by over-expression of calpastatin in Tg-CAST, OVE26/CAST and db/db-CAST mice. Conclusions: This study has demonstrated a novel role of calpain in mitochondrial ROS generation, which contributes to apoptosis in endothelial cells during hyperglycemia. Thus, over-expression of calpastatin inhibits reduces ROS production and ameliorates endothelium-dependent vascular dysfunction in mouse models of diabetes.

Abstract P311: Blocking Succinate Release Enhances Mitochondrial Reactive Oxygen Species Generation And Worsens Ischemia-reperfusion Injury

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Alexander S Milliken ◽  
Sergiy M Nadtochiy ◽  
Paul S Brookes
Keyword(s):  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Reactive Oxygen Species Generation ◽  
Ros Generation ◽  
Ros Production ◽  
Succinate Oxidation ◽  
Fluorescence Measurements ◽  
Mitochondrial Ros ◽  
The Impact ◽  
Infarction Heart

Succinate is a metabolite that plays a central role in ischemia-reperfusion (IR) injury,which is relevant to myocardial infarction (heart attack) and stroke. Succinateaccumulates during ischemia and is rapidly consumed at reperfusion driving reactiveoxygen species (ROS) generation at complex-I (Cx-I) and III of the mitochondrial electrontransport chain. This ROS production triggers cell-death, leading to tissue necrosis.Although succinate oxidation has been extensively studied and exploited as a noveltherapeutic target, only 1/3 of the succinate accumulated in ischemia is oxidized atreperfusion, with the remaining 2/3 being released from the cell via monocarboxylatetransporter 1 (MCT1). Extracellular succinate is thought to be pro-inflammatory, and ithas been proposed that preventing succinate release may be therapeutically beneficial.To determine the impact of preventing succinate release on IR injury, we comparedfunctional recovery (i.e. rate x pressure product, RPP) and infarction (i.e. tissue necrosis)of Langendorff perfused mouse hearts treated with an MCT1 inhibitor, AR-C155858,versus vehicle control. This revealed that succinate retention worsens IR injury (i.e.increased infarction and decreased functional recovery) likely due to increased ROS. Totest this hypothesis, we utilized a Langendorff apparatus positioned within aspectrofluorimeter, which permits real-time fluorescence measurements in beatingmouse hearts. Using the mitochondria targeted superoxide probe, MitoSOX red tomeasure ROS production at reperfusion + AR-C155858, demonstrated that succinateretention leads to enhanced mitochondrial ROS generation at the onset of reperfusion.Overall, these results suggest that inhibiting succinate release in the context of IR injurymay not be a viable therapeutic approach, regardless of any downstream anti-inflammatory effects.

Trichomonas Vaginalis Induces Apoptosis via ROS and ER Stress Through ER-mitochondria Crosstalk in Human Cervical Epithelial Cells

2021 ◽  
Author(s):  
Fei Fei Gao ◽  
Juan-Hua Quan ◽  
Min A Lee ◽  
Wei Ye ◽  
Jae-Min Yuk ◽  
...  
Keyword(s):  
Stress Response ◽  
Epithelial Cells ◽  
Er Stress ◽  
Mitochondrial Dysfunction ◽  
Parasite Burden ◽  
Dependent Manner ◽  
Ros Production ◽  
Er Stress Response ◽  
Siha Cells ◽  
Mitochondrial Ros

Abstract Background: Human trichomoniasis is one of the most common sexually transmitted infections; however, its pathogenesis remains unclear. Here, we investigated the role of the endoplasmic reticulum (ER) in apoptosis induction by T. vaginalis in human cervical epithelial SiHa cellsMethods: We evaluated the cytotoxicity, apoptosis, reactive oxygen species (ROS) production, mitochondrial membrane potential (MMP), ER stress response, and Bcl-2 family protein expressions using LDH assay, immunocytochemistry, flow cytometry, JC-1 dye staining, and western blotting.Results: T. vaginalis induced LDH-dependent cytotoxicity, mitochondrial ROS production, and apoptosis in SiHa cells, parasite burden- and infection time-dependently. T. vaginalis also induced ER stress response and mitochondrial dysfunction, such as MMP depolarization and imbalance in levels of Bcl-2 family proteins, in SiHa cells in a parasite burden- and infection time-dependent manner. Pretreatment with N-Acetyl cysteine (ROS scavenger) or 4-phenylbutyric acid (4-PBA, ER stress inhibitor) significantly alleviated apoptosis, ROS production, mitochondrial dysfunction, and ER stress response in a dose-dependent manner. These data suggested that SiHa cell apoptosis is affected by ROS and ER stress after T. gondii infection. In addition, T. vaginalis induced ASK1 and JNK phosphorylation in SiHa cells, however 4-PBA or SP600125 (JNK inhibitor) pretreatment significantly attenuated ASK1/JNK phosphorylation, mitochondrial dysfunction, apoptosis, and ER stress response in SiHa cells, dose-dependently.Conclusions: T. vaginalis induces mitochondrial apoptosis via ROS and parasite-mediated ER stress via the IRE1/ASK1/JNK/Mcl-1 pathways, and also induces ER stress response directly and mitochondrial ROS-dependently in human cervical epithelial SiHa cells, thus, T. vaginalis induces apoptosis via ROS and ER stress through ER-mitochondria crosstalk in human cervical epithelial cells. These results expand our understanding of the molecular mechanisms underlying the pathogenesis of human trichomoniasis.

Mitochondrial Dysfunction in Aging and Neurodegeneration

2019 ◽  
pp. 76-101
Author(s):  
Vaibhav Walia ◽  
Munish Garg
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Mitochondrial Dysfunction ◽  
Neurodegenerative Disorders ◽  
Electron Transport Chain ◽  
Tricarboxylic Acid ◽  
Atp Production ◽  
Important Target ◽  
Transport Chain ◽  
Cellular Apoptosis

Mitochondria are a dynamic organelle of the cell involved in the various biological processes. Mitochondria are the site of the adenosine triphosphate (ATP) production, electron transport chain (ETC), oxidation of fatty acids, tricarboxylic acid (TCA), and cellular apoptosis. Besides these, mitochondria are the site of production of reactive oxygen species (ROS), which further disrupts the normal functioning of this organelle also making mitochondria itself as an important target of oxidative stress. Thus, mitochondria serve as an important target in the process of neurodegeneration. In the present chapter, the authors describe mitochondria and its functioning, dynamics, and the mitochondrial dysfunction in aging and neurodegenerative disorders (NDs).

P6348Phospholamban antisense oligonucleotides drive the reversal of cardiac dysfunction and multiple heart failure parameters during murine dilated cardiomyopathy

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
D Spaeter ◽  
A Hidalgo Gonzalez ◽  
Z Elbeck ◽  
S T Yeh ◽  
H Siga ◽  
...  
Keyword(s):  
Heart Failure ◽  
Ejection Fraction ◽  
Cardiac Function ◽  
Dilated Cardiomyopathy ◽  
Transcriptome Profiling ◽  
Bioinformatic Analysis ◽  
Systolic Volume ◽  
Genetic Ablation ◽  
Gene Therapy Approach ◽  
End Diastolic Volume

Abstract Background Mice lacking muscle LIM protein (Mlp/Cspr3 −/−) develop dilated cardiomyopathy (DCM). Previous work established this model to be amenable to improvements in cardiac function by genetic ablation of phospholamban (PLN). Purpose To test the hypothesis that therapeutic reductions of PLN would similarly improve cardiac function, Mlp KO mice were administered an antisense oligonucleotide (ASO) targeting PLN. Methods Echocardiography measurements of ejection fraction (EF), end-diastolic volume (EDV) and end-systolic volume (ESV) were performed before and after treatment. In addition, global transcriptome profiling using 3'RNA-seq was performed to identify gene expression changes in diseased Mlp KO mice and following PLN ASO treatments. Mlp KO mice with ejection fraction (EF%) of less than 45% (median, 37.6%; interquartile range, 32.2–42.0%) were treated with vehicle (n=10) or PLN ASO (n=9) for 4 weeks. Results Three subcutaneous injections of PLN ASO were administered to Mlp KO mice resulting in 50–70% PLN reductions. Echocardiography performed at study end revealed improvements of EF (60±8 vs. 46±12%), ESV (31±11 vs. 56±21μl) and EDV (79±22 vs. 100±25μl) with PLN ASO treatment. Corrected for baseline values, PLN ASO treatment improved all echocardiographic measurements (p<0.001). Transcriptional analyses revealed that PLN ASO treatment reduced expression of heart failure related markers, such as Myh7 (−70%), Nppa (−72%), Nppb (−71%), Acta1 (−84%) and Ankrd1 (−40%), p<0.05 vs. vehicle. In addition, genes not previously known to be dysregulated in this model, Edn3 and Xirp2, were identified and shown to be reduced following PLN ASO treatment by 71% and 67%, respectively (p<0.001). Bioinformatic analysis suggested improvement of known and novel heart failure associated pathways by PLN inhibition in this model. In conclusion, antisense inhibition of PLN reduced functional and transcriptional indices of heart failure in a DCM model. In view of the failed CUPID trials, a gene therapy approach to improve SERCA2a activity, targeting PLN with ASO may be advantageous due to a likely more robust pharmacological profile.

The screening of albumin as a key serum component to prevent neutrophil extracellular traps release by selectively inhibiting mitochondrial ROS generation

2020 ◽  
Author(s):  
Yue Zheng ◽  
Yuanfeng Zhu ◽  
Xin Liu ◽  
Hang Zheng ◽  
Yongjun Yang ◽  
...  
Keyword(s):  
Neutrophil Extracellular Traps ◽  
Extracellular Dna ◽  
Organ Injury ◽  
Ros Generation ◽  
Ros Production ◽  
Serum Free ◽  
Extracellular Traps ◽  
Mitochondrial Ros ◽  
Serum Component ◽  
Microbial Defense

Neutrophil extracellular traps (NETs) are extracellular DNA webs released from neutrophils to mediate host anti-microbial defense. As NETs could also induce thrombosis and cause organ injury, their release should be strictly controlled. However, it is not well understood about the intrinsic mechanisms that prevent unfavorable NETs. Herein, an accidental finding of NETs release from human peripheral neutrophils was firstly described in serum free culture, and it was also determined as a conserved effect for serum to prevent NETs. In contrast to canonical NETs induced by phorbol-12-myristate-13-acetate (PMA), NETs formation by serum free culture was rapid and without prevalent NETosis. Next, albumin was screened out as a key serum component that mediated the suppression of NETs. Moreover, NETs induced upon serum or albumin deficiency were independent of the canonical pathway that involves NOX2 activation and cytosol ROS production. Instead, the generation of mitochondrial ROS (mtROS) was upregulated to promote NETs release. Albumin exhibited mtROS scavenging activity and thus inhibited NETs. Serum free culture also induces the release of NET-bound oxidized mtDNA which stimulated IFN-β production. Overall, our research provides new evidences that characterize the NETs production in serum free culture and determine the mechanisms of serum albumin to inhibit NETs.

scholarly journals The DWORF micropeptide enhances contractility and prevents heart failure in a mouse model of dilated cardiomyopathy

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Catherine A Makarewich ◽  
Amir Z Munir ◽  
Gabriele G Schiattarella ◽  
Svetlana Bezprozvannaya ◽  
Olga N Raguimova ◽  
...  
Keyword(s):  
Heart Failure ◽  
Mouse Model ◽  
Dilated Cardiomyopathy ◽  
Open Reading Frame ◽  
Contractile Dysfunction ◽  
Lim Domain ◽  
Reading Frame ◽  
Lim Domain Protein ◽  
Attractive Candidate ◽  
Genetic Deletion

Calcium (Ca2+) dysregulation is a hallmark of heart failure and is characterized by impaired Ca2+ sequestration into the sarcoplasmic reticulum (SR) by the SR-Ca2+-ATPase (SERCA). We recently discovered a micropeptide named DWORF (DWarf Open Reading Frame) that enhances SERCA activity by displacing phospholamban (PLN), a potent SERCA inhibitor. Here we show that DWORF has a higher apparent binding affinity for SERCA than PLN and that DWORF overexpression mitigates the contractile dysfunction associated with PLN overexpression, substantiating its role as a potent activator of SERCA. Additionally, using a well-characterized mouse model of dilated cardiomyopathy (DCM) due to genetic deletion of the muscle-specific LIM domain protein (MLP), we show that DWORF overexpression restores cardiac function and prevents the pathological remodeling and Ca2+ dysregulation classically exhibited by MLP knockout mice. Our results establish DWORF as a potent activator of SERCA within the heart and as an attractive candidate for a heart failure therapeutic.

Denervation-induced skeletal muscle atrophy is associated with increased mitochondrial ROS production

2007 ◽  
Vol 293 (3) ◽  
pp. R1159-R1168 ◽  
Author(s):  
Florian L. Muller ◽  
Wook Song ◽  
Youngmok C. Jang ◽  
Yuhong Liu ◽  
Marian Sabia ◽  
...  
Keyword(s):  
Muscle Mass ◽  
Muscle Atrophy ◽  
Common Factor ◽  
Skeletal Muscle Atrophy ◽  
Ros Generation ◽  
Ros Production ◽  
Muscle Mitochondria ◽  
Mitochondrial Ros ◽  
Hindlimb Muscle ◽  
Old Mice

Reactive oxygen species (ROS), especially mitochondrial ROS, are postulated to play a significant role in muscle atrophy. We report a dramatic increase in mitochondrial ROS generation in three conditions associated with muscle atrophy: in aging, in mice lacking CuZn-SOD ( Sod1−/−), and in the neurodegenerative disease, amyotrophic lateral sclerosis (ALS). ROS generation in muscle mitochondria is nearly threefold higher in 28- to 32-mo-old than in 10-mo-old mice and is associated with a 30% loss in gastrocnemius mass. In Sod1−/− mice, muscle mitochondrial ROS production is increased >100% in 20-mo compared with 5-mo-old mice along with a >50% loss in muscle mass. ALS G93A mutant mice show a 75% loss of muscle mass during disease progression and up to 12-fold higher muscle mitochondrial ROS generation. In a second ALS mutant model, H46RH48Q mice, ROS production is approximately fourfold higher than in control mice and is associated with a less dramatic loss (30%) in muscle mass. Thus ROS production is strongly correlated with the extent of muscle atrophy in these models. Because each of the models of muscle atrophy studied are associated to some degree with a loss of innervation, we were interested in determining whether denervation plays a role in ROS generation in muscle mitochondria isolated from hindlimb muscle following surgical sciatic nerve transection. Seven days postdenervation, muscle mitochondrial ROS production increased nearly 30-fold. We conclude that enhanced generation of mitochondrial ROS may be a common factor in the mechanism underlying denervation-induced atrophy.

Sign in / Sign up

Export Citation Format

Share Document