scholarly journals Vitamin K2 Modulates Organelle Damage and Tauopathy Induced by Streptozotocin and Menadione in SH-SY5Y Cells

Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 983
Author(s):  
Shruti Shandilya ◽  
Kavindra Kumar Kesari ◽  
Janne Ruokolainen
Keyword(s):  
Cell Death ◽  
Membrane Potential ◽  
Er Stress ◽  
Mitochondrial Membrane Potential ◽  
Tau Protein ◽  
Mitochondrial Membrane ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Vitamin K2 ◽  
Total Tau

Vitamin K2, known for its antioxidative and anti-inflammatory properties, can act as a potent neuroprotective molecule. Despite its action against mitochondrial dysfunction, the mechanism underlying the links between the protective effects of vitamin K2 and endoplasmic reticulum (ER) stress along with basal levels of total tau protein and amyloid-beta 42 (Aβ42) has not been elucidated yet. To understand the neuroprotective effect of vitamin K2 during metabolic complications, SH-SY5Y cells were treated with streptozotocin for 24 h and menadione for 2 h in a dose-dependent manner, followed by post-treatment of vitamin K2 for 5 h. The modulating effects of vitamin K2 on cell viability, lactate dehydrogenase release, reactive oxygen species (ROS), mitochondrial membrane potential, ER stress marker (CHOP), an indicator of unfolded protein response (UPR), inositol requiring enzyme 1 (p-IRE1α), glycogen synthase kinase 3 (GSK3α/β), total tau and Aβ42 were studied. Results showed that vitamin K2 significantly reduces neuronal cell death by inhibiting cytotoxicity and ROS levels and helps in the retainment of mitochondrial membrane potential. Moreover, vitamin K2 significantly decreased the expression of CHOP protein along with the levels and the nuclear localization of p-IRE1 α, thus showing its significant role in inhibiting chronic ER stress-mediated UPR and eventually cell death. In addition, vitamin K2 significantly down-regulated the expression of GSK3 α/β together with the levels of total tau protein, with a petite effect on secreted Aβ42 levels. These results suggested that vitamin K2 alleviated mitochondrial damage, ER stress and tauopathy-mediated neuronal cell death, which highlights its role as new antioxidative therapeutics targeting related cellular processes.

scholarly journals Peroxiredoxin II Maintains the Mitochondrial Membrane Potential against Alcohol-Induced Apoptosis in HT22 Cells

Antioxidants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Mei-Hua Jin ◽  
Jia-Bin Yu ◽  
Hu-Nan Sun ◽  
Ying-Hua Jin ◽  
Gui-Nan Shen ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Ht22 Cells ◽  
Apoptotic Protein ◽  
Intracellular Ros ◽  
Induced Apoptosis ◽  
The Brain

Excessive alcohol intake can significantly reduce cognitive function and cause irreversible learning and memory disorders. The brain is particularly vulnerable to alcohol-induced ROS damage; the hippocampus is one of the most sensitive areas of the brain for alcohol neurotoxicity. In the present study, we observed significant increasing of intracellular ROS accumulations in Peroxiredoxin II (Prx II) knockdown HT22 cells, which were induced by alcohol treatments. We also found that the level of ROS in mitochondrial was also increased, resulting in a decrease in the mitochondrial membrane potential. The phosphorylation of GSK3β (Ser9) and anti-apoptotic protein Bcl2 expression levels were significantly downregulated in Prx II knockdown HT22 cells, which suggests that Prx II knockdown HT22 cells were more susceptible to alcohol-induced apoptosis. Scavenging the alcohol-induced ROS with NAC significantly decreased the intracellular ROS levels, as well as the phosphorylation level of GSK3β in Prx II knockdown HT22 cells. Moreover, NAC treatment also dramatically restored the mitochondrial membrane potential and the cellular apoptosis in Prx II knockdown HT22 cells. Our findings suggest that Prx II plays a crucial role in alcohol-induced neuronal cell apoptosis by regulating the cellular ROS levels, especially through regulating the ROS-dependent mitochondrial membrane potential. Consequently, Prx II may be a therapeutic target molecule for alcohol-induced neuronal cell death, which is closely related to ROS-dependent mitochondria dysfunction.

scholarly journals Botanical Alkyl Hydroquinone Derivative HQ17(3) Induces Calcium-Associated Mitochondrial Damage and Mitophagy to Exert Ctotoxicity to Philadelphila Chromosome(+) ALL Cells

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 5800-5800
Author(s):  
Yin-Chen Chou ◽  
Chia-Wei Chen ◽  
Yuan-Yeh Kuo ◽  
Liang-In Lin ◽  
Chung-Yi Hu
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Membrane Potential ◽  
Er Stress ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Nuclear Translocation ◽  
Mitochondrial Superoxide ◽  
Apoptosis Inducing Factor ◽  
Mitotracker Green

Abstract Introduction: Acute lymphoblastic leukemias (ALLs) harboring t(9;22)(Ph+-ALL) are very high risk (VHR) ALL displaying poor clinical outcome irrespective of intensive chemotherapies plus tyrosine kinase inhibitor (TKI) treatment. HQ17(3)[10'(Z),13'(E),15'(E)-heptadecatrienyl hydroquinone] isolated from sap of the lacquer tree showed rapid (within 24hrs) and potent cytotoxic effect at micromolar concentration on several ALL cell lines, including Imatinib-refractory Ph+-ALL SUP-B15 cells, but spared normal PB leukocytes, and showed nontoxic in experimental rats after 28-day injection. Therefore HQ17(3) presents as a potential anti-leukemic agents and provide a platform for exploring anti-leukemic adjuvants. Our previous study showed HQ17(3)-induced rapid cell demise, characterized by oxidative stress, mitochondrial membrane potential disturbance, loss of membrane integrity, and nuclear DNA fragmentation. HQ17(3)-induced cell death is a caspase-independent program, and is different from the RIP1-mediated controlled necroptosis since both pan-caspase inhibitor and RIP-1 inhihitor failed to protect SUP-B15 cells from death. The ER stress markers (chaperon Grp78 and phosphorylated-eIF2α) were up-regulated as early as 5hrs after HQ17(3) treatment. Here we aim to illustrate the characters of the HQ17(3)-induced non-classical death on Ph+-SUP-B15 cells, focus on ER stress-associated mitochondrial Ca2+ homeostasis. Methods: Cell death and changes of mitochondria in response to HQ17(3) w/wo inhibitors were analyzed. Cells were stained by Annexin V/PI and analyzed by flow cytometry for cell death. Mitochondria mass, mitochondrial Ca2+ accumulation was detected by fluorescent Mitotracker Green and Rhod-2 probes, respectively. Mitochondrial superoxide was measured by Mitosox stain. Western blot analysis was used to analyze MFN1/2, OPA1 (mitochondrial markers). Nuclear accumulation of apoptosis inducing factor (AIF), co-localization of mitochondrial COX-IV and LC3-II (mitophagy) were revealed by immunofluorescence stain and confocal microscopy. Results: We showed mitochondrial Ca2+ accumulation at the early time when ER stress occurred (Fig 1), accompanied by mitochondrial superoxide elevation, followed by loss of mitochondrial membrane potential (MMP) and nuclear translocation of apoptosis-inducing factor (AIF). HQ17(3) treatment lead to decreased mitochondrial proteins MFN1/2 and OPA1, while Mitotracker Green stain showed significant loss of mitochondrial mass preceded cell death, indicating damaged mitochondria underwent fission followed by mitophagy. Immunofluorescence stain showed evidence of mitophagy (COX IV and LC3B co-localization). Calpain-1 inhibitor PD150606 blocked AIF nuclear translocation but only slightly reduced the HQ17(3)-induced cell death (Fig 2). Further, Ca2+ chelator Bapta-AM prevented mitochondrial superoxide production, MMP loss, mitophagy (Fig 3), and rescued cell death (Fig 1) more effectively. Conclusion: In Ph+-ALL SUP-B15 cells, HQ17(3) induce ER stress by yet-defined mechanism, this mobilizes Ca2+ to mitochondria and acts in multi-facet: a) results in AIF cleavage and translocation to mediate nuclear chromatin fragmentation, b) Ca2+-overload leads to oxidative stress and perturbs mitochondria integrity, c) damaged mitochondria trigger extensive mitophagy and cell death ensues. Therefore, agents that help elicit similar intricate effector network associated with ER/mitochondria stress will have potential to be adjuvants in aiding control of the Ph+ VHR-ALL cells refractory to conventional chemotherapies and TKI regime. Disclosures No relevant conflicts of interest to declare.

scholarly journals Cofilin1 oxidation links oxidative distress to mitochondrial demise and neuronal cell death

2020 ◽  
Author(s):  
Lena Hoffmann ◽  
Marcel S. Waclawczyk ◽  
Eva-Maria Hanschmann ◽  
Manuela Gellert ◽  
Marco B. Rust ◽  
...  
Keyword(s):  
Cell Death ◽  
Membrane Potential ◽  
Mitochondrial Respiration ◽  
Mitochondrial Membrane ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Ht22 Cells ◽  
Cell Death Pathways ◽  
Mitochondrial Ros ◽  
Ros Accumulation

AbstractMany cell death pathways, including apoptosis, regulated necrosis and ferroptosis are relevant for neuronal cell death and share common mechanisms such as the formation of reactive oxygen species (ROS). However, which molecular signaling pathways contribute to related pathologies and how they are interconnected remains elusive.Here, we present the role of cofilin1 in regulating mitochondrial functions and neuronal impairment. Cofilin1 deletion in neuronal HT22 cells exerted increased mitochondrial resilience, assessed by quantification of mitochondrial ROS production, mitochondrial membrane potential and ATP levels. HT22 cells deficient for cofilin1 exhibited a profound glycolytic shift to meet their energy demand in conditions of erastin and glutamate toxicity, whereas control cells were metabolically impaired and underwent ferroptosis and oxytosis, respectively. Further, cofilin1 was confirmed as a key player in glutamate-mediated excitotoxicity in primary cortical neurons isolated from cofilin1flx/flx, CaMKIIα-Cre knock-out mice. Mitochondrial respiration and cell viability were significantly preserved in cofilin1-/- primary neurons under conditions of excitotoxicity.Using isolated mitochondria and recombinant cofilin1, we provide a further link to toxicity-related mitochondrial impairment mediated by oxidized cofilin1. Wildtype cofilin1 directly affected the mitochondrial membrane potential, mitochondrial ROS accumulation and mitochondrial respiration. The detrimental impact of cofilin1 on mitochondria depends on oxidation of cysteine residues at positions 139 and 147.Our findings show that the actin-regulating protein cofilin1 acts as a redox sensor in oxidative cell death pathways of ferroptosis and oxytosis, and also promotes glutamate excitotoxicity. Oxidized cofilin1 links ROS accumulation to mitochondrial demise and neuronal cell death. Protective effects by cofilin1 inhibition are particularly attributed to preserved mitochondrial integrity and function. Thus, interfering with the oxidation and pathological activation of cofilin1 may offer an effective therapeutic strategy in neurodegenerative diseases.

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.

scholarly journals Protein Kinase Cδ Targets Mitochondria, Alters Mitochondrial Membrane Potential, and Induces Apoptosis in Normal and Neoplastic Keratinocytes When Overexpressed by an Adenoviral Vector

1999 ◽  
Vol 19 (12) ◽  
pp. 8547-8558 ◽  
Author(s):  
Luowei Li ◽  
Patricia S. Lorenzo ◽  
Krisztina Bogi ◽  
Peter M. Blumberg ◽  
Stuart H. Yuspa
Keyword(s):  
Cell Death ◽  
Membrane Potential ◽  
Protein Kinase ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Fluorescent Protein ◽  
Protein Fusion ◽  
Cell Death Pathway ◽  
Morphological Criteria ◽  
Protein Kinase Cδ

ABSTRACT Inactivation of protein kinase Cδ (PKCδ) is associated with resistance to terminal cell death in epidermal tumor cells, suggesting that activation of PKCδ in normal epidermis may be a component of a cell death pathway. To test this hypothesis, we constructed an adenovirus vector carrying an epitope-tagged PKCδ under a cytomegalovirus promoter to overexpress PKCδ in normal and neoplastic keratinocytes. While PKCδ overexpression was detected by immunoblotting in keratinocytes, the expression level of other PKC isozymes, including PKCα, PKCɛ, PKCζ, and PKCη, did not change. Calcium-independent PKC-specific kinase activity increased after infection of keratinocytes with the PKCδ adenovirus. Activation of PKCδ by 12-O-tetradecanoylphorbol-13-acetate (TPA) at a nanomolar concentration was lethal to normal and neoplastic mouse and human keratinocytes overexpressing PKCδ. Lethality was inhibited by PKC selective inhibitors, GF109203X and Ro-32-0432. TPA-induced cell death was apoptotic as evidenced by morphological criteria, TUNEL (terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling) assay, DNA fragmentation, and increased caspase activity. Subcellular fractionation indicated that PKCδ translocated to a mitochondrial enriched fraction after TPA activation, and this finding was confirmed by confocal microscopy of cells expressing a transfected PKCδ-green fluorescent protein fusion protein. Furthermore, activation of PKCδ in keratinocytes altered mitochondrial membrane potential, as indicated by rhodamine-123 fluorescence. Mitochondrial inhibitors, rotenone and antimycin A, reduced TPA-induced cell death in PKCδ-overexpressing keratinocytes. These results indicate that PKCδ can initiate a death pathway in keratinocytes that involves direct interaction with mitochondria and alterations of mitochondrial function.

scholarly journals The U95 Protein of Human Herpesvirus 6B Interacts with Human GRIM-19: Silencing of U95 Expression Reduces Viral Load and Abrogates Loss of Mitochondrial Membrane Potential

2007 ◽  
Vol 82 (2) ◽  
pp. 1011-1020 ◽  
Author(s):  
W. M. Yeo ◽  
Yuji Isegawa ◽  
Vincent T. K. Chow
Keyword(s):  
Cell Death ◽  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Human Herpesvirus ◽  
Ultrastructural Changes ◽  
Gene Encoding ◽  
Interacting Protein ◽  
Functional Aspects ◽  
Infected Cells

ABSTRACT To better understand the pathogenesis of human herpesvirus 6 (HHV-6), it is important to elucidate the functional aspects of immediate-early (IE) genes at the initial phase of the infection. To study the functional role of the HHV-6B IE gene encoding U95, we generated a U95-Myc fusion protein and screened a pretransformed bone marrow cDNA library for U95-interacting proteins, using yeast-two hybrid analysis. The most frequently appearing U95-interacting protein identified was GRIM-19, which belongs to the family of genes associated with retinoid-interferon mortality and serves as an essential component of the oxidative phosphorylation system. This interaction was verified by both coimmunoprecipitation and confocal microscopic coimmunolocalization. Short-term HHV-6B infection of MT-4 T-lymphocytic cells induced syncytial formation, resulted in decreased mitochondrial membrane potential, and led to progressively pronounced ultrastructural changes, such as mitochondrial swelling, myelin-like figures, and a loss of cristae. Compared to controls, RNA interference against U95 effectively reduced the U95 mRNA copy number and abrogated the loss of mitochondrial membrane potential. Our results indicate that the high affinity between U95 early viral protein and GRIM-19 may be closely linked to the detrimental effect of HHV-6B infection on mitochondria. These findings may explain the alternative cell death mechanism of expiration, as opposed to apoptosis, observed in certain productively HHV-6B-infected cells. The interaction between U95 and GRIM-19 is thus functionally and metabolically significant in HHV-6B-infected cells and may be a means through which HHV-6B modulates cell death signals by interferon and retinoic acid.

scholarly journals Involvement of intracellular Ca2+ and K+ in dissipation of the mitochondrial membrane potential and cell death induced by extracellular ATP in hepatocytes

1992 ◽  
Vol 288 (1) ◽  
pp. 207-213 ◽  
Author(s):  
J P Zoeteweij ◽  
B van de Water ◽  
H J de Bont ◽  
G J Mulder ◽  
J F Nagelkerke
Keyword(s):  
Cell Death ◽  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Rat Hepatocytes ◽  
Extracellular Atp ◽  
Complete Loss ◽  
Isolated Rat Hepatocytes ◽  
Isolated Mitochondria ◽  
Isolated Rat

Isolated rat hepatocytes were incubated with extracellular ATP to induce a prolonged increase in intracellular Ca2+ ([Ca2+]i) and a loss of viability within 2 h. By using video-intensified fluorescence microscopy, the effects of exposure to extracellular ATP on [Ca2+]i, mitochondrial membrane potential (MMP) and cell viability were determined simultaneously in individual living hepatocytes. The increase in [Ca2+]i on exposure to ATP was followed by a decreasing MMP; there were big differences between individual cells. Complete loss of the MMP occurred before cell death was observed. Omission of K+ from the incubation medium decreased the cytotoxicity of ATP; under these conditions, intracellular K+ was decreased by more than 80%. Treatment with nigericin also depleted intracellular K+ and decreased ATP-induced toxicity. Protection against loss of viability by means of a decrease in intracellular [K+] was reflected by maintenance of the MMP. These observations suggest that ATP-induced cell death may be caused by a mechanism that has been described for isolated mitochondria: after an increase in Ca2+ levels, a K+ influx into mitochondria is induced, which finally disrupts the MMP and leads to cell death.

Anti-Glycophorin C Induces a Loss of Mitochondrial Membrane Potential but Fails To Activate Apoptotic Caspases.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4097-4097
Author(s):  
Gregory A. Denomme ◽  
Jonathan Micieli ◽  
Jenny Shu ◽  
Dan Wang ◽  
Bernard J. Fernandes
Keyword(s):  
Cell Death ◽  
Membrane Potential ◽  
Growth Inhibition ◽  
Mitochondrial Membrane Potential ◽  
K562 Cell ◽  
Mitochondrial Membrane ◽  
K562 Cells ◽  
Suppressive Effect ◽  
Glycophorin C

Abstract The human erythrocyte transmembrane sialoglycoprotein, glycophorin C (GYPC), plays a functional role in regulating red cell shape and mechanical stability. Antibodies to GYPC cause hemolytic disease of the fetus and newborn (HDFN) that is associated with classical Fcγ receptor-mediated phagocytosis. However, in vitro clonogenic studies with cord blood progenitor cells suggest that anti-GYPC also suppresses erythropoiesis, which is consistent with the observations of severe and early fetal anemia and late onset neonatal anemia [Transfus Med2005;15:125–32]. The mechanism of the suppressive effect on erythropoiesis is unknown. The K562 erythroleukemic cell line treated with anti-GYPC is a potential model system to study the suppressive effect of anti-GYPC. The present in vitro studies were designed to confirm the effect of anti-GYPC on K562 cell growth and viability, and to evaluate changes in mitochondrial membrane potential, phosphatidylserine (PS) expression, propidium iodide (PI) binding, and caspase activation. K562 cells fail to grow in the presence of anti-GYPC confirming earlier CFU-E/BFU-E studies [Brit J Haematol2006;133:443–4], and increased the exofacial expression of PS/PI over time. This process was caspase-independent as demonstrated by the failure of Z-VAD, a caspase inhibitor, to reverse growth inhibition and PS/PI expression. A loss of mitochondrial membrane potential was demonstrated using JC-1, a cationic dye that is sensitive to potential-dependent accumulation or loss in mitochondria. There was a 50% increase in K562 cell mitochondrial membrane potential disruption after 2 days of culture with anti-GYPC (see figure). Morphological examination of May Grunwalde Giemsa-stained K562 cells treated with anti-GYPC for 2 days showed a decrease in mitotic activity compared to isotype treated cells. By day 4, the anti-GYPC treated cells were showing evidence of plasma membrane damage and cell death resulting from fragmentation and dissolution of the cytoplasm. The addition of hemin, an oxidative form of iron protoporphyrin IX known to induce erythroid differentiation of K562 cells, to anti-GYPC treated cells reversed growth inhibition by 45% but did not prevent the loss of mitochondrial membrane potential. Overall, although caspases appear to be unimportant in anti-GYPC induced cell death, the mitchondria play an important role as the early events leading to antibody-mediated suppression of erythropoiesis. Mitochondrial Membrane Potential Disruption by Anti-GYPC Mitochondrial Membrane Potential Disruption by Anti-GYPC

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