scholarly journals Protein kinase Cε targets respiratory chain and mitochondrial membrane potential but not F 0 F 1 ‐ATPase in renal cells injured by oxidant

2018 ◽  
Vol 119 (11) ◽  
pp. 9394-9407 ◽  
Author(s):  
Grazyna Nowak ◽  
Diana Bakajsova‐Takacsova
2021 ◽  
Author(s):  
Ming-Zhang Xie ◽  
Chun Guo ◽  
Jia-Qi Dong. BA ◽  
Jie Zhang ◽  
Ke-Tao Sun ◽  
...  

Abstract Background: Exposure to glyoxal, the smallest dialdehyde, is associated with several diseases; humans are routinely exposed to glyoxal because of its ubiquitous presence in foods and the environment. The aim of this study was to examine the damage caused by glyoxal in human aortic endothelial cells. Methods: Cell survival assays and quantitative fluorescence assays were performed to measure DNA damage; oxidative stress was detected by colorimetric assays and quantitative fluorescence, and the mitogen-activated protein kinase pathways were assessed using western blotting. Results: Exposure to glyoxal was found to be linked to abnormal glutathione activity, the collapse of mitochondrial membrane potential, and the activation of mitogen-activated protein kinase pathways. However, DNA damage and thioredoxin oxidation were not induced by dialdehydes. Conclusions: Intracellular glutathione, members of the mitogen-activated protein kinase pathways, and the mitochondrial membrane potential are all critical targets of glyoxal. These findings provide novel insights into the molecular mechanisms perturbed by glyoxal and may facilitate the development of new therapeutics and diagnostic markers for cardiovascular diseases.


Endocrinology ◽  
2007 ◽  
Vol 148 (5) ◽  
pp. 2037-2044 ◽  
Author(s):  
John J. Peluso ◽  
Xiufang Liu ◽  
Jonathan Romak

The present studies were designed to 1) describe changes in both the mitochondrial membrane potential and ATP content of spontaneously immortalized granulosa cells as they undergo apoptosis, 2) identify some of the downstream events that are activated by progesterone (P4), and 3) relate these downstream events to changes in mitochondrial function and apoptotic cell death. These studies revealed that in response to serum deprivation, the mitochondrial membrane potential initially hyperpolarizes and ATP content increases. That this increase in ATP is required for apoptosis was demonstrated by the finding that oligomycin inhibited the increase in ATP and apoptosis. Piridoxalphosphate-6-azopeyl-2′-4′-disulfonic acid, an inhibitor of purinergic receptors, which are activated by ATP, also inhibited apoptosis due to serum withdrawal. This study provides additional support for ATP’s causative role in apoptosis. Moreover, 8-Br-cGMP, a protein kinase G (PKG) activator, mimicked P4’s action, whereas a PKG antagonist, DT-3, attenuated P4’s suppressive effect on ATP and apoptosis. Finally, DT-3 treatment was shown to attenuate P4-regulated phosphorylation of 14-3-3σ and its binding partner, ATP synthaseβ/precursor and the amount of ATP synthaseβ/precursor that bound to 14-3-3σ. Based on these data, it is proposed that P4 prevents apoptosis in part by activating PKG, which in turn maintains the interaction between ATP synthaseβ/precursor and 14-3-3σ. In the absence of P4-induced PKG activity, we further propose that some ATP synthaseβ precursor dissociates from 14-3-3σ, resulting in its activation and incorporation into the ATP synthase complex, which ultimately results in an increase in ATP and apoptosis.


1999 ◽  
Vol 19 (12) ◽  
pp. 8547-8558 ◽  
Author(s):  
Luowei Li ◽  
Patricia S. Lorenzo ◽  
Krisztina Bogi ◽  
Peter M. Blumberg ◽  
Stuart H. Yuspa

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.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1356-1356
Author(s):  
Wenli Liu ◽  
Yueqin Liu ◽  
Ruihong Wang ◽  
Cuiling Li ◽  
Chuxia Deng ◽  
...  

Abstract Abstract 1356 Poster Board I-378 Introduction Olfactomedin 4 (OLFM4), also called hGC-1, GW112 and pDP4, was first identified and specifically expressed in hematopoietic myeloid cells. OLFM4 expression in myeloid cells is regulated by transcription factors, PU1 and NF-κB. It has significant homology in its C-terminal domain with other olfactomedin-related proteins. OLFM4 encodes a 510 amino acid N-linked glycoprotein. The exact biological function of OLFM4, especially in neutrophils, is currently undefined. To characterize the in vivo function of OLFM4, we generated OLFM4 deficient mice (OLFM4-/-) and investigated its potential role in neutrophil functioins. Results 1) In this study, we showed that OLFM4 is a secreted glycoprotein and is also localized in the mitochondria, cytoplasm and cell membrane fractions of neutrophils. We demonstrated that OLFM4 interacts with GRIM-19 (Genes associated with Retinoid-IFN-induced Mortality-19), an apoptosis related protein, in the neutrophil mitochondria using co-immuoprecipitation assay. GRIM-19 is a subunit of complex I of mitochondrial respiratory chain and is essential for maintenance of mitochondrial membrane potential. Our result suggests that OLFM4 appears to be a novel component of complex I of mitochondrial respiratory chain and may be involved in regulation of mitochondrial membrane potential. 2) Mice heterozygous (OLFM4+/-) and homozygous (OLFM4-/-) for the null mutation in OLFM4 appeared to have normal development, fertility, and viability relative to wild-type (WT) mice. Whole blood analysis, differential leukocyte counts, blood chemistry and bone marrow smears were normal in OLFM4-/- mice, suggesting that OLFM4 is not essential for normal development and hematopoiesis in mice. 3) In response to LPS, fMLP and E.coli bacteria challenge, neutrophils from OLFM4-/- mice showed significantly reduced superoxide (O2−) and hydrogen peroxide (H2O2) production compared with WT mice. These results suggest that OLFM4 is an essential component to mediate O2− and H2O2 production in the neutrophil mitochondria under inflammation stimuli. 4) Exogenous H2O2 induced neutrophil apoptosis in a time and dose dependent manner in WT mice, but this induction of apoptosis was significantly reduced in OLFM4-/- mice. This result suggests that OLFM4 sensitizes and mediates H2O2-induced apoptosis in neutrophils. 5) Furthermore, we demonstrated that H2O2-stimulated mitochondrial membrane permeability reduction and caspase-3 and caspase-9 activation were inhibited in the neutrophils of OLFM4-/- mice. This result confirmed our hypothesis that OLFM4 may be involved in maintenance of mitochondrial membrane potential and suggests that OLFM4 may have opposite role as GRIM-19. 6) Moreover, Bax association with mitochondria and the cytoplasmic translocation of Omi/HtrA2 and Smac/DIABLO in response to H2O2 were inhibited in the neutrophils of OLFM4-/- mice. Conclusion Our results suggest: 1) OLFM4 has multiple subcellular localizations including mitochondria, cytoplasm, and cell membrane in neutrophils. The interaction of OLFM4 with GRIM-19 in the mitochondria suggests that OLFM4 is novel component of complex I of mitochondrial respiratory chain in the mitochondria of neutrophils, 2) OLFM4 is a novel mitochondrial molecule that is essential for O2− and H2O2 production in the neutrophils in the presence of inflammation stimuli, 3) Loss of OLFM4 in neutrophils does not trigger spontaneous apoptosis. However, OLFM4 sensitizes oxidative stress-induced apoptosis in mouse neutrophils. OLFM4 is involved in the regulation of mitochondria membrane potential and sensitizes cytoplasmic translocation of Omi/HtrA2 and Smac/DIABLO and caspases-3 and caspase-9 mediated apoptosis in the presence of oxidative stress. Disclosures No relevant conflicts of interest to declare.


2013 ◽  
Vol 9 ◽  
pp. 1551-1558 ◽  
Author(s):  
Xu-Wen Li ◽  
Jennifer Herrmann ◽  
Yi Zang ◽  
Philippe Grellier ◽  
Soizic Prado ◽  
...  

Aurachins are myxobacterial 3-farnesyl-4(1H)-quinolone derived compounds initially described as respiratory chain inhibitors, more specifically as inhibitors of various cytochrome complexes. They are also known as potent antibiotic compounds. We describe herein the first synthesis of aurachin D through a key Conrad–Limpach reaction. The same strategy was used to reach some ring as opposed to chain analogues, allowing for the description of structure–activity relationships. Biological screening of the analogues showed antiparasitic, cytotoxic, antibacterial and antifungal activities, and depletion of the mitochondrial membrane potential. The strongest activity was found on Plasmodium falciparum with a selectivity index of 345, compared to Vero cells, for the natural product and its geranyl analogue. The loss of mitochondrial membrane potential induced by aurachins in human U-2 OS osteosarcoma cells was studied, showing the best activity for aurachin D and a naphthalene analogue, yet without totally explaining the observed cytotoxic activity of the compounds. Finally, a synthetic entry is given to the complete carboheterocyclic core of aurachin H through the N-oxidation/epoxidation of aurachin D and a shorter chain analogue, followed by subsequent biomimetic cyclization.


2001 ◽  
Vol 382 (8) ◽  
pp. 1227-1234 ◽  
Author(s):  
Hajo Haase ◽  
Wim Wätjen ◽  
Detmar Beyersmann

Abstract Zinc ions have both essential and toxic effects on mammalian cells. Here we report the ability of zinc to act as an inducer of apoptosis in C6 rat glioma cells. Incubation with 150 to 300 M ZnCl2 caused cell death that was characterized as apoptotic by internucleosomal DNA fragmentation, formation of apoptotic bodies, nuclear fragmentation and breakdown of the mitochondrial membrane potential. On the other hand, zinc deprivation by the membrane permeable chelator TPEN [N,N,N,N,tetrakis (2-pyridylmethyl)ethylenediamine] also induced programmed death in this cell line, indicating the existence of intracellular zinc levels below and above which apoptosis is induced. Zincinduced apoptosis in C6 cells was independent of major signaling pathways (protein kinase C, mitogen activated protein kinase and guanylate cyclase) and protein synthesis, but was increased by facilitating zinc uptake with the ionophore pyrithione. Lanthanum(III)chloride was also able to increase the net zinc uptake, but nevertheless apoptotic features and zinc toxicity were reduced. Remarkably, lanthanum suppressed the zincinduced breakdown of the mitochondrial membrane potential. We conclude that in C6 cells lanthanum acts in two different ways, as a promoter of net zinc uptake and as a suppressor of zincinduced apoptosis.


2020 ◽  
Author(s):  
Xuejun Wang ◽  
Li Zhang ◽  
Mengwen Feng ◽  
Hao Zhang ◽  
Jia Xu ◽  
...  

Abstract Background: It has been acknowledged that endocrine activity is associated with the function of multiple systems in vivo. The apelin-13 peptide has been demonstrated to play a crucial role in physiological and pathological processes. However, the function of apelin-13 peptide in doxorubicin (DOX)-induced cardiotoxicity is unknown. Methods: We explored the function and mechanism of apelin-13 peptide in apoptosis and oxidative stress by cell counting kit-8 (CCK-8) assay, trypan blue staining, TUNEL, lactate dehydrogenase (LDH), mitochondrial membrane potential assay kit with JC-1 (JC-1) and western blot in vitro. Then we verified the effect of apelin-13 in vivo by detecting serum apelin-13, CKMB, LDH, cardiac troponin I (cTnI) and cardiac troponin T (cTnT). EF, FS and LVEDs were used to identify the structural modification by echocardiography. Sirius red staining and HE staining assay were used to detecting the myocardial fibers alteration under apelin-13 treatment.Results: Treatment with apelin-13 peptide significantly enhanced cell viability, mitochondrial membrane potential, but reduced LDH release, rate of apoptotic cells and activation of caspase-3 in vitro. In mice, apelin-13 alleviated the heart dysfunction induced by DOX. 4-oxo-6-((pyrimidin-2-ylthio)methyl)-4H-pyran-3-yl 4-nitrobenzoate (ML221) inhibited the effect of extracellular signal-related kinases (ERK), phosphatidylinositol 3 kinases (PI3K) and protein kinase B (AKT) proteins phosphorylation expression compared with DOX.Conclusion: The apelin-13 and apelin receptor (APJ) interaction on the cell membrane inhibits apoptosis through the ERK/mitogen-activated protein kinase (MAPK) and PI3K/AKT signaling pathways. Our research gives a first glimpse on the biological function and mechanism of apelin-13 on cardiotoxicity.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ming-Zhang Xie ◽  
Chun Guo ◽  
Jia-Qi Dong ◽  
Jie Zhang ◽  
Ke-Tao Sun ◽  
...  

Abstract Background Exposure to glyoxal, the smallest dialdehyde, is associated with several diseases; humans are routinely exposed to glyoxal because of its ubiquitous presence in foods and the environment. The aim of this study was to examine the damage caused by glyoxal in human aortic endothelial cells. Methods Cell survival assays and quantitative fluorescence assays were performed to measure DNA damage; oxidative stress was detected by colorimetric assays and quantitative fluorescence, and the mitogen-activated protein kinase pathways were assessed using western blotting. Results Exposure to glyoxal was found to be linked to abnormal glutathione activity, the collapse of mitochondrial membrane potential, and the activation of mitogen-activated protein kinase pathways. However, DNA damage and thioredoxin oxidation were not induced by dialdehydes. Conclusions Intracellular glutathione, members of the mitogen-activated protein kinase pathways, and the mitochondrial membrane potential are all critical targets of glyoxal. These findings provide novel insights into the molecular mechanisms perturbed by glyoxal, and may facilitate the development of new therapeutics and diagnostic markers for cardiovascular diseases.


2009 ◽  
Vol 54 (1) ◽  
pp. 280-287 ◽  
Author(s):  
Metodi V. Stankov ◽  
Thomas Lücke ◽  
Anibh M. Das ◽  
Reinhold E. Schmidt ◽  
Georg M. N. Behrens

ABSTRACT Mitochondrial dysfunction as a consequence of mitochondrial DNA (mtDNA) depletion due to therapy with nucleoside analogue reverse transcriptase inhibitors (NRTI) has been proposed as a pathogenic mechanism leading to lipoatrophy in HIV-infected patients. The aim of our study was to investigate the impact of NRTI treatment on mtDNA abundance and the activities of respiratory chain complexes in primary human subcutaneous preadipocytes (phsPA). We studied adipocyte phenotypes, viability, and differentiation (CCAAT/enhancer-binding protein α [C/EBPα] and peroxisome proliferator-activated receptor γ [PPARγ] expression) and adiponectin production, mtDNA content, mitochondrial membrane potential, mitochondrial mass, and respiratory chain enzyme and citrate synthase activities in both proliferating and differentiating phsPA. Cells were exposed to zidovudine (6 μM), stavudine (d4T; 3 μM), and zalcitabine (ddC; 0.1 μM) for 8 weeks. NRTI-induced mtDNA depletion occurred in proliferating and differentiating phsPA after exposure to therapeutic drug concentrations of d4T and ddC. At these concentrations, ddC and d4T led to an almost 50% decrease in the number of mtDNA copies per cell without major impact on adipocyte differentiation. Despite mtDNA depletion by NRTI, the activities of the respiratory chain complexes, the mitochondrial membrane potential, and the mitochondrial mass were found to be unaffected. Severe NRTI-mediated mtDNA depletion in phsPA is not inevitably associated with impaired respiratory chain activity or altered mitochondrial membrane potential.


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