scholarly journals EPAC1 Inhibition Protects the Heart from Doxorubicin-Induced Toxicity

2021 ◽  
Author(s):  
Marianne Mazevet ◽  
Maxance Ribeiro ◽  
Anissa Belhadef ◽  
Delphine Dayde ◽  
Anna Llach ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cell Death ◽  
Membrane Potential ◽  
Dilated Cardiomyopathy ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Dna Intercalation ◽  
Antitumoral Activity ◽  
Ros Generation

Rationale: The widely used chemotherapeutic agent Doxorubicin (Dox) induces cardiotoxicity leading to dilated cardiomyopathy and heart failure. This cardiotoxicity has been related to ROS generation, DNA intercalation, bioenergetic distress and cell death. However, alternative mechanisms are emerging, focusing on signaling pathways. Objective: We investigated the role of Exchange Protein directly Activated by cAMP (EPAC), key factor in cAMP signaling, in Dox-induced cardiotoxicity. Methods and Results: Dox was administrated in vivo (10 +/- 2 mg/kg, i.v.; with analysis at 2, 6 and 15 weeks post injection) in WT and EPAC1 KO C57BL6 mice. Cardiac function was analyzed by echocardiography and intracellular Ca2+ homeostasis by confocal microscopy in isolated ventricular cardiomyocytes. 15 weeks post-injections, Dox-treated WT mice, developed a dilated cardiomyopathy with decreased ejection fraction, increased telediastolic volume and impaired Ca2+ homeostasis, which were totally prevented in the EPAC1 KO mice. The underlying mechanisms were investigated in neonatal and adult rat cardiac myocytes under Dox treatment (1-10 uM). Flow cytometry, Western blot, BRET sensor assay, and RT-qPCR analysis showed that Dox induced DNA damage and cardiomyocyte cell death with apoptotic features rather than necrosis, including Ca2+-CaMKKβ-dependent opening of the Mitochondrial Permeability Transition Pore, dissipation of the Mitochondrial membrane potential, caspase activation, cell size reduction, and DNA fragmentation. Dox also led to an increase in both cAMP concentration and EPAC1 protein level and activity. The pharmacological inhibition of EPAC1 (CE3F4) but not EPAC2 alleviated the whole Dox-induced pattern of alterations including DNA damage, Mitochondrial membrane potential, apoptosis, mitochondrial biogenesis, dynamic, and fission/fusion balance, and respiratory chain activity, suggesting a crucial role of EPAC1 in these processes. Importantly, while preserving cardiomyocyte integrity, EPAC1 inhibition potentiated Dox-induced cell death in several human cancer cell lines. Conclusion: Thus, EPAC1 inhibition could be a valuable therapeutic strategy to limit Dox-induced cardiomyopathy without interfering with its antitumoral activity.

scholarly journals The Interferon Stimulator Mitochondrial Antiviral Signaling Protein Facilitates Cell Death by Disrupting the Mitochondrial Membrane Potential and by Activating Caspases

2009 ◽  
Vol 84 (5) ◽  
pp. 2421-2431 ◽  
Author(s):  
Chia-Yi Yu ◽  
Ruei-Lin Chiang ◽  
Tsung-Hsien Chang ◽  
Ching-Len Liao ◽  
Yi-Ling Lin
Keyword(s):  
Cell Death ◽  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Caspase Cleavage ◽  
Infected Cells ◽  
Mitochondrial Antiviral Signaling ◽  
Antiviral Innate Immunity ◽  
Viral Components

ABSTRACT Interferon (IFN) signaling is initiated by the recognition of viral components by host pattern recognition receptors. Dengue virus (DEN) triggers IFN-β induction through a molecular mechanism involving the cellular RIG-I/MAVS signaling pathway. Here we report that the MAVS protein level is reduced in DEN-infected cells and that caspase-1 and caspase-3 cleave MAVS at residue D429. In addition to its well-known function in IFN induction, MAVS is also a proapoptotic molecule that triggers disruption of the mitochondrial membrane potential and activation of caspases. Although different domains are required for the induction of cytotoxicity and IFN, caspase cleavage at residue 429 abolished both functions of MAVS. The apoptotic role of MAVS in viral infection and double-stranded RNA (dsRNA) stimulation was demonstrated in cells with reduced endogenous MAVS expression induced by RNA interference. Even though IFN-β promoter activation was largely suppressed, DEN production was not affected greatly in MAVS knockdown cells. Instead, DEN- and dsRNA-induced cell death and caspase activation were delayed and attenuated in the cells with reduced levels of MAVS. These results reveal a new role of MAVS in the regulation of cell death beyond its well-known function of IFN induction in antiviral innate immunity.

scholarly journals Efficaciousness of Low Affinity Compared to High Affinity TSPO Ligands in the Inhibition of Hypoxic Mitochondrial Cellular Damage Induced by Cobalt Chloride in Human Lung H1299 Cells

Biomedicines ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 106
Author(s):  
Nidal Zeineh ◽  
Nunzio Denora ◽  
Valentino Laquintana ◽  
Massimo Franco ◽  
Abraham Weizman ◽  
...  
Keyword(s):  
Cell Death ◽  
Membrane Potential ◽  
Cell Line ◽  
Mitochondrial Membrane Potential ◽  
Atp Synthase ◽  
Mitochondrial Membrane ◽  
Cobalt Chloride ◽  
Ros Generation ◽  
High Affinity ◽  
Affinity Ligand

The 18 kDa translocator protein (TSPO) plays an important role in apoptotic cell death, including apoptosis induced by the hypoxia mimicking agent cobalt chloride (CoCl2). In this study, the protective effects of a high (CB86; Ki = 1.6 nM) and a low (CB204; Ki = 117.7 nM) affinity TSPO ligands were investigated in H1299 lung cancer cell line exposed to CoCl2. The lung cell line H1299 was chosen in the present study since they express TSPO and able to undergo programmed cell death. The examined cell death markers included: ATP synthase reversal, reactive oxygen species (ROS) generation, mitochondrial membrane potential (Δψm) depolarization, cellular toxicity, and cellular viability. Pretreatment of the cells with the low affinity ligand CB204 at a concentration of 100 µM suppressed significantly (p < 0.05 for all) CoCl2-induced cellular cytotoxicity (100%), ATP synthase reversal (67%), ROS generation (82%), Δψm depolarization (100%), reduction in cellular density (97%), and also increased cell viability (85%). Furthermore, the low affinity TSPO ligand CB204, was harmless when given by itself at 100 µM. In contrast, the high affinity ligand (CB86) was significantly effective only in the prevention of CoCl2–induced ROS generation (39%, p < 0.001), and showed significant cytotoxic effects when given alone at 100 µM, as reflected in alterations in ADP/ATP ratio, oxidative stress, mitochondrial membrane potential depolarization and cell death. It appears that similar to previous studies on brain-derived cells, the relatively low affinity for the TSPO target enhances the potency of TSPO ligands in the protection from hypoxic cell death. Moreover, the high affinity TSPO ligand CB86, but not the low affinity ligand CB204, was lethal to the lung cells at high concentration (100 µM). The low affinity TSPO ligand CB204 may be a candidate for the treatment of pulmonary diseases related to hypoxia, such as pulmonary ischemia and chronic obstructive pulmonary disease COPD.

DNA damage is an early event in doxorubicin-induced cardiac myocyte death

2006 ◽  
Vol 291 (3) ◽  
pp. H1273-H1280 ◽  
Author(s):  
Thomas L'Ecuyer ◽  
Sanjeev Sanjeev ◽  
Ronald Thomas ◽  
Raymond Novak ◽  
Lauri Das ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cell Death ◽  
Membrane Potential ◽  
Cardiac Myocytes ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Cardiac Myocyte ◽  
Dna Lesions ◽  
Doxorubicin Treatment ◽  
P53 Activation

Anthracyclines are antitumor agents the main clinical limitation of which is cardiac toxicity. The mechanism of this cardiotoxicity is thought to be related to generation of oxidative stress, causing lethal injury to cardiac myocytes. Although protein and lipid oxidation have been documented in anthracycline-treated cardiac myocytes, DNA damage has not been directly demonstrated. This study was undertaken to determine whether anthracyclines induce cardiac myocyte DNA damage and whether this damage is linked to a signaling pathway culminating in cell death. H9c2 cardiac myocytes were treated with the anthracycline doxorubicin at clinically relevant concentrations, and DNA damage was assessed using the alkaline comet assay. Doxorubicin induced DNA damage, as shown by a significant increase in the mean tail moment above control, an effect ameliorated by inclusion of a free radical scavenger. Repair of DNA damage was incomplete after doxorubicin treatment in contrast to the complete repair observed in H2O2-treated myocytes after removal of the agent. Immunoblot analysis revealed that p53 activation occurred subsequent in time to DNA damage. By a fluorescent assay, doxorubicin induced loss of mitochondrial membrane potential after p53 activation. Chemical inhibition of p53 prevented doxorubicin-induced cell death and loss of mitochondrial membrane potential without preventing DNA damage, indicating that DNA damage was proximal in the events leading from doxorubicin treatment to cardiac myocyte death. Specific doxorubicin-induced DNA lesions included oxidized pyrimidines and 8-hydroxyguanine. DNA damage therefore appears to play an important early role in anthracycline-induced lethal cardiac myocyte injury through a pathway involving p53 and the mitochondria.

Abstract 4362: Antibodies against KChIP2 Induce Ionic Imbalance and Cell Death in Isolated Rat Cardiomyocytes

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Sangita Choudhury ◽  
Michael Schnell ◽  
Jan Lüdemann ◽  
Alexander Staudt ◽  
Heyo K Kroemer ◽  
...  
Keyword(s):  
Cell Death ◽  
Membrane Potential ◽  
Dilated Cardiomyopathy ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Caspase 3 ◽  
Nuclear Translocation ◽  
Rat Cardiomyocytes ◽  
Ionic Imbalance ◽  
Isolated Rat

Disturbances of humoral immunity have been described in patients with dilated cardiomyopathy (DCM). Antibodies against Kv channel-interacting proteins (KChIPs) may be associated with heart failure. Isolated rat cardiomyocytes were treated with antibodies against rat KChIP2 (80 pmol/ml) up to 24 hours. RNA and proteins were isolated after two hours by standard procedures and mRNA (TaqMan®) and protein (Western blot) expression was quantified. Translocations of NF-κB subunits p50, p65, c-Rel, and Rel-B were measured in nuclear protein extracts by ELISA after 60 minutes. Mitochondrial membrane potential ΔΨm and caspase-3 and -9 activities were determined by flow cytometry. Necrotic and apoptotic cells were distinguished by staining with Hoechst 33258 and propidium iodide. Total Ca 2+ and K + concentrations were quantified by a colorimetric assay and atomic absorption spectrometry, respectively, and normalized to the protein content of the cells. Antibodies against KChIP2 induced nuclear translocation of all NF-κB subunits analyzed. Pre-incubation with a blocking peptide or an NF-κB inhibitor, CAPE, prevented nuclear translocation. Anti-KChIP2-treatment for two hours significantly reduced KChIP2 mRNA (55±10%; n=4) and protein (73 ±5%, n =4) expression compared to cells treated with experimental buffer (100%). Treatment for 24 hours did not induce changes in mitochondrial membrane potential, ΔΨm. Caspase-3 and -9 activities were not altered as well. The anti-KChIP2-treated cell population consisted of 75±3% necrotic, 2±1% apoptotic, and 13±2% viable cells. In contrast, cells treated with experimental buffer were viable to 86±1%. After five minutes, anti-KChIP2 induced significant increases in total intracellular Ca 2+ (plus 11±2%) and K + (plus 18±2%) concentrations. These antibody-mediated effects were prevented in the presence of a blocking peptide. Antibodies against KChIP2 induce ionic imbalance, activate the transcription factor NF-κB, down-regulate KChIP2 expression and enhance cell death rate probably due to necrosis. Antibodies against KChIP2 may contribute to the development and progression of dilated cardiomyopathy.

scholarly journals Neurosupportive Role of Vanillin, a Natural Phenolic Compound, on Rotenone Induced Neurotoxicity in SH-SY5Y Neuroblastoma Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Chinnasamy Dhanalakshmi ◽  
Thamilarasan Manivasagam ◽  
Jagatheesan Nataraj ◽  
Arokiasamy Justin Thenmozhi ◽  
Musthafa Mohamed Essa
Keyword(s):  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Phenolic Compound ◽  
Mitochondrial Membrane ◽  
Mapk Pathway ◽  
Expression Patterns ◽  
Neuroblastoma Cells ◽  
Ros Generation ◽  
Cyt C

Vanillin, a phenolic compound, has been reported to offer neuroprotection against experimental Huntington’s disease and global ischemia by virtue of its antioxidant, anti-inflammatory, and antiapoptotic properties. The present study aims to elucidate the underlying neuroprotective mechanism of vanillin in rotenone induced neurotoxicity. Cell viability was assessed by exposing SH-SY5Y cells to various concentrations of rotenone (5–200 nM) for 24 h. The therapeutic effectiveness of vanillin against rotenone was measured by pretreatment of vanillin at various concentrations (5–200 nM) and then incubation with rotenone (100 nM). Using effective dose of vanillin (100 nM), mitochondrial membrane potential, levels of reactive oxygen species (ROS), and expression patterns of apoptotic markers were assessed. Toxicity of rotenone was accompanied by the loss of mitochondrial membrane potential, increased ROS generation, release of cyt-c, and enhanced expressions of proapoptotic and downregulation of antiapoptotic indices via the upregulation of p38 and JNK-MAPK pathway proteins. Our results indicated that the pretreatment of vanillin attenuated rotenone induced mitochondrial dysfunction, oxidative stress, and apoptosis. Thus, vanillin may serve as a potent therapeutic agent in the future by virtue of its multiple pharmacological properties in the treatment of neurodegenerative diseases including PD.

Modulation of neuronal mitochondrial membrane potential by the NMDA receptor: role of arachidonic acid

1997 ◽  
Vol 777 (1-2) ◽  
pp. 69-74 ◽  
Author(s):  
Antonio Camins ◽  
Francesc X Sureda ◽  
Cecilia Gabriel ◽  
Mercè Pallàs ◽  
Elena Escubedo ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Membrane Potential ◽  
Nmda Receptor ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane

The role of mitochondrial membrane potential in ischemic heart failure

Mitochondrion ◽  
2011 ◽  
Vol 11 (5) ◽  
pp. 700-706 ◽  
Author(s):  
Bernhard Kadenbach ◽  
Rabia Ramzan ◽  
Rainer Moosdorf ◽  
Sebastian Vogt
Keyword(s):  
Heart Failure ◽  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Ischemic Heart ◽  
Ischemic Heart Failure

Abstract 371: Mitochondrial Antiviral Signaling (MAVS) Protects Cardiomyocytes Under Oxidative Stress by Interfering with Bax-Mediated Cell Death

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Toshitaka Yajima ◽  
Stanley Park ◽  
Hanbing Zhou ◽  
Michinari Nakamura ◽  
Mitsuyo Machida ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Membrane Potential ◽  
Cytochrome C ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Cytochrome C Release ◽  
Antiviral Signaling ◽  
Cell Death Pathway ◽  
The Impact

MAVS is a mitochondrial outer membrane protein that activates innate antiviral signaling by recognizing cytosolic viral RNAs and DNAs. While the discovery of MAVS is the first molecular evidence that links mitochondria to innate immune mechanisms, it is still unclear whether MAVS affects mitochondrial cell death as a member of caspase activation and recruitment domain (CARD)-containing proteins. We found that MAVS interacts with Bax through CARD by Yeast two-hybrid and a series of immunoprecipitation (IP) assay, which led us to hypothesize that MAVS functions not only in the innate antiviral mechanisms but also in the mitochondrial cell death pathway. Methods: 1) We examined molecular interaction between MAVS and Bax under oxidative stress by IP using isolated myocytes with H2O2 stimulation and the heart post ischemia-reperfusion (I/R). 2) We evaluated the effect of MAVS on mitochondrial membrane potential and apoptosis under H2O2 stimulation using isolated myocytes with adenoviral MAVS knockdown. 3) We investigated the impact of MAVS on %myocardial infarction (%MI) post I/R using cardiac-specific MAVS knockout (cKO) and transgenic (cTg) mice which we have originally generated. 4) We examined the effect of MAVS on recombinant Bax (rBax)-mediated cytochrome c release using isolated mitochondria from wild type (WT) and MAVS KO mice. Results: 1) The amount of Bax pulled down with MAVS was significantly increased in isolated myocytes with 0.2 mM H2O2 compared to those without stimulation (mean±SD; 1.808±0.14, n=5, p<0.001) and in the heart post I/R compared to sham (2.2±1.19, n=3, p=0.0081). 2) Myocytes with MAVS knockdown showed clear abnormalities in mitochondrial membrane potential and caspace-3 cleavage with 0.2 mM H2O2 compared to control cardiomyocytes. 3) MAVS cKO had significantly larger %MI than WT (81.9 ± 5.8% vs. 42.6 ± 13.6%, n=8, p=0.0008). In contrast, MAVS cTg had significantly smaller %MI that WT (30.0 ± 4.8% vs. 49.2 ± 4.8%, n=10, p=0.0113). 4) Mitochondria from MAVS KO exhibited cytochrome c release after incubation with 2.5 μ g of rBax while those from WT required 10 μ g of rBax. Conclusion: These results demonstrate that MAVS protects cardiomyocyte under oxidative stress by interfering with Bax-mediated cytochrome c release from mitochondria.

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