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Sulyman AO, Fulcher J, Crossley S, Fatokun AA, Olorunniji FJ. Shikonin and Juglone Inhibit Mycobacterium tuberculosis Low-Molecular-Weight Protein Tyrosine Phosphatase a (Mt-PTPa). BIOTECH 2023; 12:59. [PMID: 37754203 PMCID: PMC10526854 DOI: 10.3390/biotech12030059] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 08/21/2023] [Accepted: 09/12/2023] [Indexed: 09/28/2023] Open
Abstract
Low-molecular-weight protein tyrosine phosphatases (LMW-PTPs) are involved in promoting the intracellular survival of Mycobacterium tuberculosis (Mtb), the causative organism of tuberculosis. These PTPs directly alter host signalling pathways to evade the hostile environment of macrophages and avoid host clearance. Among these, protein tyrosine phosphatase A (Mt-PTPa) is implicated in phagosome acidification failure, thereby inhibiting phagosome maturation to promote Mycobacterium tuberculosis (Mtb) survival. In this study, we explored Mt-PTPa as a potential drug target for treating Mtb. We started by screening a library of 502 pure natural compounds against the activities of Mt-PTPa in vitro, with a threshold of 50% inhibition of activity via a <500 µM concentration of the candidate drugs. The initial screen identified epigallocatechin, myricetin, rosmarinic acid, and shikonin as hits. Among these, the naphthoquinone, shikonin (5, 8-dihydroxy-2-[(1R)-1-hydroxy-4-methyl-3-pentenyl]-1,4-naphthoquinone), showed the strongest inhibition (IC50 33 µM). Further tests showed that juglone (5-hydroxy-1,4-naphthalenedione), another naphthoquinone, displayed similar potent inhibition of Mt-PTPa to shikonin. Kinetic analysis of the inhibition patterns suggests a non-competitive inhibition mechanism for both compounds, with inhibitor constants (Ki) of 8.5 µM and 12.5 µM for shikonin and juglone, respectively. Our findings are consistent with earlier studies suggesting that Mt-PTPa is susceptible to specific allosteric modulation via a non-competitive or mixed inhibition mechanism.
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Affiliation(s)
- Abdulhakeem O. Sulyman
- Department of Biochemistry, Faculty of Pure and Applied Sciences, Kwara State University, Malete 241103, Nigeria
- School of Pharmacy & Biomolecular Sciences, Faculty of Science, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK
| | - Jessie Fulcher
- School of Pharmacy & Biomolecular Sciences, Faculty of Science, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK
| | - Samuel Crossley
- School of Pharmacy & Biomolecular Sciences, Faculty of Science, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK
| | - Amos A. Fatokun
- School of Pharmacy & Biomolecular Sciences, Faculty of Science, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK
| | - Femi J. Olorunniji
- School of Pharmacy & Biomolecular Sciences, Faculty of Science, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK
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Synthesis of thia-Michael-Type Adducts between Naphthoquinones and N-Acetyl-L-Cysteine and Their Biological Activity. Molecules 2022; 27:molecules27175645. [PMID: 36080409 PMCID: PMC9457610 DOI: 10.3390/molecules27175645] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 08/25/2022] [Accepted: 08/31/2022] [Indexed: 11/16/2022] Open
Abstract
A series of naphthoquinones, namely, 1,4-naphthoquinone, menadione, plumbagin, juglone, naphthazarin, and lawsone, were reacted with N-acetyl-L-cysteine, and except for lawsone, which did not react, the related adducts were obtained. After the tuning of the solvent and reaction conditions, the reaction products were isolated as almost pure from the complex reaction mixture via simple filtration and were fully characterized. Therefore, the aim of this work was to evaluate whether the antitumor activity of new compounds of 1,4-naphthoquinone derivatives leads to an increase in ROS in tumor cell lines of cervical carcinoma (HeLa), neuroblastoma (SH-SY5Y), and osteosarcoma (SaOS2, U2OS) and in normal dermal fibroblast (HDFa). The MTT assay was used to assay cell viability, the DCF-DA fluorescent probe to evaluate ROS induction, and cell-cycle analysis to measure the antiproliferative effect. Compounds 8, 9, and 12 showed a certain degree of cytotoxicity towards all the malignant cell lines tested, while compound 11 showed biological activity at higher IC50 values. Compounds 8 and 11 induced increases in ROS generation after 1 h of exposure, while after 48 h of treatment, only 8 induced an increase in ROS formation in HeLa cells. Cell-cycle analysis showed that compound 8 caused an increase in the number of G0/G1-phase cells in the HeLa experiment, while for the U2OS and SH-SY5Y cell lines, it led to an accumulation of S-phase cells. Therefore, these novel 1,4-naphthoquinone derivatives may be useful as antitumoral agents in the treatment of different cancers.
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Ngo K, Castillo P, Laine RA, Sun Q. Effects of Menadione on Survival, Feeding, and Tunneling Activity of the Formosan Subterranean Termite. INSECTS 2021; 12:insects12121109. [PMID: 34940197 PMCID: PMC8707845 DOI: 10.3390/insects12121109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 11/30/2021] [Accepted: 12/02/2021] [Indexed: 11/16/2022]
Abstract
The Formosan subterranean termite, Coptotermes formosanus Shiraki, is a highly destructive pest and a cosmopolitan invasive species. Sustainable termite management methods have been improving with the search for novel insecticides that are effective, safe, and cost efficient. Menadione, also known as vitamin K3, is a synthetic analogue and biosynthetic precursor of vitamin K with low mammalian toxicity. Menadione has shown insecticidal activity in several insects, presumably due to interference with mitochondrial oxidative phosphorylation. However, little is known about its effectiveness against termites. In this study, we evaluated the toxicity and repellency of menadione in C. formosanus. Our results showed that menadione affected the survival and feeding activity of termites both in filter paper and substrate (sand) treatments, and menadione influenced termite tunneling activity in treated sand. In a no-choice assay, ≥90% mortality after seven days and minimal or no food consumption were recorded when sand was treated with menadione at 6 to 600 ppm. In a two-choice assay with a combination of treated and untreated sand, termites were deterred by menadione at 6 to 600 ppm and exhibited low mortality (≤30%) over seven days, while tunneling activity was prevented with 60 to 600 ppm of menadione treatment. Overall, our study demonstrated dose-dependent toxicity and repellency of menadione in C. formosanus. The potential use of menadione as an alternative termite control agent is discussed.
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Affiliation(s)
- Kieu Ngo
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, USA; (K.N.); (P.C.)
| | - Paula Castillo
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, USA; (K.N.); (P.C.)
| | - Roger A. Laine
- Departments of Biological Sciences and Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA
- Correspondence: (R.A.L.); (Q.S.)
| | - Qian Sun
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, USA; (K.N.); (P.C.)
- Correspondence: (R.A.L.); (Q.S.)
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4
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Zhang YY, Ni ZJ, Elam E, Zhang F, Thakur K, Wang S, Zhang JG, Wei ZJ. Juglone, a novel activator of ferroptosis, induces cell death in endometrial carcinoma Ishikawa cells. Food Funct 2021; 12:4947-4959. [PMID: 34100505 DOI: 10.1039/d1fo00790d] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Ferroptosis is a novel iron-dependent cell death pathway mainly caused by an abnormal redox state and associated with various diseases including cancer. Recently, much attention has been paid to natural compounds that are involved in its activation and inhibition. This is the first ever study to demonstrate the role of juglone isolated from Carya cathayensis green peel in inducing autophagy and inhibiting endometrial cancer (EC) cell migration. Subsequently, Fe2+ accumulation, lipid peroxidation, GSH depletion, the upregulation of HMOX1, and heme degradation to Fe2+ were reported. Juglone was involved in inducing autophagy and inhibiting cell migration and endoplasmic reticulum stress, which are the new hallmarks of cancer treatment. Collectively, our data indicate that juglone as a functional food ingredient induces the programmed cell death of EC cells by activating oxidative stress and suggest a novel therapeutic approach for the treatment and prevention of EC.
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Affiliation(s)
- Yuan-Yuan Zhang
- School of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, People's Republic of China. and Collaborative Innovation Center for Food Production and Safety, School of Biological Science and Engineering, North Minzu University, Yinchuan 750021, People's Republic of China.
| | - Zhi-Jing Ni
- Collaborative Innovation Center for Food Production and Safety, School of Biological Science and Engineering, North Minzu University, Yinchuan 750021, People's Republic of China.
| | - Elnur Elam
- Collaborative Innovation Center for Food Production and Safety, School of Biological Science and Engineering, North Minzu University, Yinchuan 750021, People's Republic of China.
| | - Fan Zhang
- School of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, People's Republic of China. and Collaborative Innovation Center for Food Production and Safety, School of Biological Science and Engineering, North Minzu University, Yinchuan 750021, People's Republic of China.
| | - Kiran Thakur
- School of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, People's Republic of China. and Collaborative Innovation Center for Food Production and Safety, School of Biological Science and Engineering, North Minzu University, Yinchuan 750021, People's Republic of China.
| | - Shaoyun Wang
- College of Biological Science and Technology, Fuzhou University, Fuzhou, 350108, People's Republic of China.
| | - Jian-Guo Zhang
- School of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, People's Republic of China. and Collaborative Innovation Center for Food Production and Safety, School of Biological Science and Engineering, North Minzu University, Yinchuan 750021, People's Republic of China.
| | - Zhao-Jun Wei
- School of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, People's Republic of China. and Collaborative Innovation Center for Food Production and Safety, School of Biological Science and Engineering, North Minzu University, Yinchuan 750021, People's Republic of China.
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Valério GN, Gutiérrez-Merino C, Nogueira F, Moura I, Moura JJG, Samhan-Arias AK. Human erythrocytes exposure to juglone leads to an increase of superoxide anion production associated with cytochrome b 5 reductase uncoupling. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1861:148134. [PMID: 31825806 DOI: 10.1016/j.bbabio.2019.148134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 09/30/2019] [Accepted: 12/05/2019] [Indexed: 12/11/2022]
Abstract
Cytochrome b5 reductase is an enzyme with the ability to generate superoxide anion at the expenses of NADH consumption. Although this activity can be stimulated by cytochrome c and could participate in the bioenergetic failure accounting in apoptosis, very little is known about other molecules that may uncouple the function of the cytochrome b5 reductase. Naphthoquinones are redox active molecules with the ability to interact with electron transfer chains. In this work, we made an inhibitor screening against recombinant human cytochrome b5 reductase based on naphthoquinone properties. We found that 5-hydroxy-1,4-naphthoquinone (known as juglone), a natural naphthoquinone extracted from walnut trees and used historically in traditional medicine with ambiguous health and toxic outcomes, had the ability to uncouple the electron transfer from the reductase to cytochrome b5 and ferricyanide. Upon complex formation with cytochrome b5 reductase, juglone is able to act as an electron acceptor leading to a NADH consumption stimulation and an increase of superoxide anion production by the reductase. Our results suggest that cytochrome b5 reductase could contribute to the measured energetic failure in the erythrocyte apoptosis induced by juglone, that is concomitant with the reactive oxygen species produced by cytochrome b5 reductase.
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Affiliation(s)
- Gabriel N Valério
- LAQV, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Carlos Gutiérrez-Merino
- Department of Biochemistry and Molecular Biology, Faculty of Sciences, Institute of Molecular Pathology Biomarkers, University of Extremadura, 06006 Badajoz, Spain
| | - Fatima Nogueira
- Global Health and Tropical Medicine, GHTM, Unidade de Ensino e Investigação de Parasitologia Médica, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa, UNL, Rua da Junqueira no 100, 1349-008 Lisbon, Portugal
| | - Isabel Moura
- LAQV, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - José J G Moura
- LAQV, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Alejandro K Samhan-Arias
- LAQV, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal; Departamento de Bioquímica, Universidad Autónoma de Madrid (UAM) and Instituto de Investigaciones Biomédicas 'Alberto Sols' (CSIC-UAM), c / Arturo Duperier 4, 28029-Madrid, Spain.
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6
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Eriksen JG, Kaalund I, Clemmensen O, Overgaard J, Pfeiffer P. Placebo-controlled phase II study of vitamin K3 cream for the treatment of cetuximab-induced rash. Support Care Cancer 2017; 25:2179-2185. [DOI: 10.1007/s00520-017-3623-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 02/06/2017] [Indexed: 01/09/2023]
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Phytotoxic studies of naphthoquinone intermediates from the synthesis of the natural product Naphthotectone. RESEARCH ON CHEMICAL INTERMEDIATES 2017. [DOI: 10.1007/s11164-017-2884-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Wang C, Liu Z, Sun Y, Chen T, Huo X, Meng Q, Liu Q, Sun H, Sun P, Peng J, Ma X, Liu K. A stronger reversal effect of the combination of dasatinib and menadione on P-gp-mediated multidrug resistance in human leukemia K562/Adr cell line. RSC Adv 2017. [DOI: 10.1039/c6ra27999f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Multidrug resistance (MDR) leads to poor efficiency of chemotherapy.
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9
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1,4-naphthoquinones: from oxidative damage to cellular and inter-cellular signaling. Molecules 2014; 19:14902-18. [PMID: 25232709 PMCID: PMC6270801 DOI: 10.3390/molecules190914902] [Citation(s) in RCA: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 09/02/2014] [Accepted: 09/11/2014] [Indexed: 12/18/2022] Open
Abstract
Naphthoquinones may cause oxidative stress in exposed cells and, therefore, affect redox signaling. Here, contributions of redox cycling and alkylating properties of quinones (both natural and synthetic, such as plumbagin, juglone, lawsone, menadione, methoxy-naphthoquinones, and others) to cellular and inter-cellular signaling processes are discussed: (i) naphthoquinone-induced Nrf2-dependent modulation of gene expression and its potentially beneficial outcome; (ii) the modulation of receptor tyrosine kinases, such as the epidermal growth factor receptor by naphthoquinones, resulting in altered gap junctional intercellular communication. Generation of reactive oxygen species and modulation of redox signaling are properties of naphthoquinones that render them interesting leads for the development of novel compounds of potential use in various therapeutic settings.
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Kumagai Y, Shinkai Y, Miura T, Cho AK. The chemical biology of naphthoquinones and its environmental implications. Annu Rev Pharmacol Toxicol 2011; 52:221-47. [PMID: 21942631 DOI: 10.1146/annurev-pharmtox-010611-134517] [Citation(s) in RCA: 227] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Quinones are a group of highly reactive organic chemical species that interact with biological systems to promote inflammatory, anti-inflammatory, and anticancer actions and to induce toxicities. This review describes the chemistry, biochemistry, and cellular effects of 1,2- and 1,4-naphthoquinones and their derivatives. The naphthoquinones are of particular interest because of their prevalence as natural products and as environmental chemicals, present in the atmosphere as products of fuel and tobacco combustion. 1,2- and 1,4-naphthoquinones are also toxic metabolites of naphthalene, the major polynuclear aromatic hydrocarbon present in ambient air. Quinones exert their actions through two reactions: as prooxidants, reducing oxygen to reactive oxygen species; and as electrophiles, forming covalent bonds with tissue nucleophiles. The targets for these reactions include regulatory proteins such as protein tyrosine phosphatases; Kelch-like ECH-associated protein 1, the regulatory protein for NF-E2-related factor 2; and the glycolysis enzyme glyceraldehyde-3-phosphate dehydrogenase. Through their actions on regulatory proteins, quinones affect various cell signaling pathways that promote and protect against inflammatory responses and cell damage. These actions vary with the specific quinone and its concentration. Effects of exposure to naphthoquinones as environmental chemicals can vary with the physical state, i.e., whether the quinone is particle bound or is in the vapor state. The exacerbation of pulmonary diseases by air pollutants can, in part, be attributed to quinone action.
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Affiliation(s)
- Yoshito Kumagai
- Doctoral Program in Biomedical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki 305-8575, Japan
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Delwar ZM, Avramidis D, Follin E, Hua Y, Siden Å, Cruz M, Paulsson KM, Yakisich JS. Cytotoxic effect of menadione and sodium orthovanadate in combination on human glioma cells. Invest New Drugs 2011; 30:1302-10. [PMID: 21553345 DOI: 10.1007/s10637-011-9680-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Accepted: 04/26/2011] [Indexed: 01/15/2023]
Abstract
Gliomas are the most common primary brain tumor, and their treatment is still a challenge. Here, we evaluated the antiproliferative effect of a novel combination of two potent oxidative stress enhancers: menadione (M) and sodium orthovanadate (SO). We observed both short-term and prolonged growth inhibitory effects of M or SO alone as well as in combination (M:SO) on DBTRG.05MG human glioma cells. A stronger antiproliferative effect was observed in the short-term proliferation assay with the M:SO combination compared to either investigated agent alone. In the long-term proliferation assay, a 10-day exposure to M:SO at concentrations of 10 μM:17.5 μM or 17.5 μM:10 μM was enough to kill 100% of the cells; no cell regrowth was observed after re-incubation in drug-free media. When used in combination, the single concentration of M and SO could be decreased by 2.5- to 5-fold of those used for each experimental drug alone and still obtain a similar antiproliferative effect. The underlying molecular mechanism was investigated by co-incubating M:SO with dithiothreitol (DTT) and genistein. Both substances partially neutralized the effects of the M:SO combination, showing additive effects. This observation suggests a role of oxidative stress and tyrosine kinase stimulation in the M:SO cytotoxic effect. Our results indicate that M:SO combination is an attractive alternative for glioma treatment that encourages further study. The neutralizing effects of genistein and DTT reveal a possibility for their use in the minimization of potential M:SO systemic toxicity.
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Affiliation(s)
- Zahid M Delwar
- Department of Clinical Neuroscience R54, Karolinska Institute, Karolinska University Hospital, Huddinge, S-141 86 Stockholm, Sweden
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Klaus V, Hartmann T, Gambini J, Graf P, Stahl W, Hartwig A, Klotz LO. 1,4-Naphthoquinones as inducers of oxidative damage and stress signaling in HaCaT human keratinocytes. Arch Biochem Biophys 2010; 496:93-100. [DOI: 10.1016/j.abb.2010.02.002] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2009] [Revised: 02/05/2010] [Accepted: 02/09/2010] [Indexed: 10/19/2022]
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Ale-Agha N, Albrecht C, Klotz LO. Loss of gap junctional intercellular communication in rat lung epithelial cells exposed to quartz particles. Biochem Biophys Res Commun 2009; 390:44-7. [DOI: 10.1016/j.bbrc.2009.09.057] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2009] [Accepted: 09/15/2009] [Indexed: 11/17/2022]
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Ale-Agha N, Galban S, Sobieroy C, Abdelmohsen K, Gorospe M, Sies H, Klotz LO. HuR regulates gap junctional intercellular communication by controlling beta-catenin levels and adherens junction integrity. Hepatology 2009; 50:1567-76. [PMID: 19676129 PMCID: PMC2784158 DOI: 10.1002/hep.23146] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
UNLABELLED Gap junctional intercellular communication (GJIC) plays a critical role in the regulation of tissue homeostasis and carcinogenesis and is modulated by the levels, subcellular localization, and posttranslational modification of gap junction proteins, the connexins (Cx). Here, using oval cell-like rat liver epithelial cells, we demonstrate that the RNA-binding protein HuR promotes GJIC through two mechanisms. First, HuR silencing lowered the levels of Cx43 protein and Cx43 messenger RNA (mRNA), and decreased Cx43 mRNA half-life. This regulation was likely due to the direct stabilization of Cx43 mRNA by HuR, because HuR associated directly with Cx43 mRNA, a transcript that bears signature adenylate-uridylate-rich (AU-rich) and uridylate-rich (U-rich) sequences in its 3'-untranslated region. Second, HuR silencing reduced both half-life and the levels of beta-catenin mRNA, also a target of HuR; accordingly, HuR silencing lowered the levels of whole-cell and membrane-associated beta-catenin. Coimmunoprecipitation experiments showed a direct interaction between beta-catenin and Cx43. Small interfering RNA (siRNA)-mediated depletion of beta-catenin recapitulated the effects of decreasing HuR levels: it attenuated GJIC, decreased Cx43 levels, and redistributed Cx43 to the cytoplasm, suggesting that depletion of beta-catenin in HuR-silenced cells contributed to lowering Cx43 levels at the membrane. Finally, HuR was demonstrated to support GJIC after exposure to a genotoxic agent, doxorubicin, or an inducer of differentiation processes, retinoic acid, thus pointing to a crucial role of HuR in the cellular response to stress and in physiological processes modulated by GJIC. CONCLUSION HuR promotes gap junctional intercellular communication in rat liver epithelial cells through two related regulatory processes, by enhancing the expression of Cx43 and by increasing the expression of beta-catenin, which, in turn, interacts with Cx43 and is required for proper positioning of Cx43 at the plasma membrane.
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Affiliation(s)
- Niloofar Ale-Agha
- Institut für umweltmedizinische Forschung (IUF) an der Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Stefanie Galban
- Institut für Biochemie und Molekularbiologie I, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany, Laboratory of Cellular and Molecular Biology, National Institute on Aging – Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
| | - Christiane Sobieroy
- Institut für Biochemie und Molekularbiologie I, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Kotb Abdelmohsen
- Laboratory of Cellular and Molecular Biology, National Institute on Aging – Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
| | - Myriam Gorospe
- Laboratory of Cellular and Molecular Biology, National Institute on Aging – Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
| | - Helmut Sies
- Institut für umweltmedizinische Forschung (IUF) an der Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany, Institut für Biochemie und Molekularbiologie I, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Lars-Oliver Klotz
- Institut für umweltmedizinische Forschung (IUF) an der Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany, Institut für Biochemie und Molekularbiologie I, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany,Correspondence should be addressed to
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15
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Lai TS, Liu Y, Tucker T, Daniel KR, Sane DC, Toone E, Burke JR, Strittmatter WJ, Greenberg CS. Identification of chemical inhibitors to human tissue transglutaminase by screening existing drug libraries. ACTA ACUST UNITED AC 2008; 15:969-78. [PMID: 18804034 DOI: 10.1016/j.chembiol.2008.07.015] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2007] [Revised: 07/16/2008] [Accepted: 07/23/2008] [Indexed: 12/20/2022]
Abstract
Human tissue transglutaminase (TGM2) is a calcium-dependent crosslinking enzyme involved in the posttranslational modification of intra- and extracellular proteins and implicated in several neurodegenerative diseases. To find specific inhibitors to TGM2, two structurally diverse chemical libraries (LOPAC and Prestwick) were screened. We found that ZM39923, a Janus kinase inhibitor, and its metabolite ZM449829 were the most potent inhibitors with IC(50) of 10 and 5 nM, respectively. In addition, two other inhibitors, including tyrphostin 47 and vitamin K(3), were found to have an IC(50) in the micromolar range. These agents used in part a thiol-dependent mechanism to inhibit TGM2, consistent with the activation of TGM2 by reduction of an intramolecular disulfide bond. These inhibitors were tested in a polyglutamine-expressing Drosophila model of neurodegeneration and found to improve survival. The TGM2 inhibitors we discovered may serve as valuable lead compounds for the development of orally active TGM2 inhibitors to treat human diseases.
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Affiliation(s)
- Thung-S Lai
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.
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16
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Circu ML, Rodriguez C, Maloney R, Moyer MP, Aw TY. Contribution of mitochondrial GSH transport to matrix GSH status and colonic epithelial cell apoptosis. Free Radic Biol Med 2008; 44:768-78. [PMID: 18267208 PMCID: PMC2275168 DOI: 10.1016/j.freeradbiomed.2007.09.011] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2007] [Revised: 08/15/2007] [Accepted: 09/12/2007] [Indexed: 01/02/2023]
Abstract
Previously, we showed that cellular glutathione/glutathione disulfide (GSH/GSSG) play an important role in apoptotic signaling, and early studies linked mitochondrial GSH (mtGSH) loss to enhanced cytotoxicity. The current study focuses on the contribution of mitochondrial GSH transport and mitochondrial GSH/GSSG status to apoptosis initiation in a nontransformed colonic epithelial cell line, NCM460, using menadione (MQ), a quinone with redox cycling bioreactivity, as a model of oxidative challenge. Our results implicate the semiquinone radical in MQ-mediated apoptosis, which was associated with marked oxidation of the mitochondrial soluble GSH and protein-bound thiol pools, mitochondria-to-cytosol translocation of cytochrome c, and activation of caspase-9. MQ-induced apoptosis was potentiated by inhibition of mtGSH uptake in accordance with exacerbated mitochondrial GSSG (mtGSSG) and protein-SSG and compromised mitochondrial respiratory activity. Moreover, cell apoptosis was prevented by N-acetyl-L-cysteine (NAC) pretreatment, which restored cellular redox homeostasis. Importantly, mtGSH transport inhibition effectively blocked NAC-mediated protection in accordance with its failure to attenuate mtGSSG. These results support the importance of mitochondrial GSH transport and the mtGSH status in oxidative cell killing.
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Affiliation(s)
- Magdalena L. Circu
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA 71130
| | - Cynthia Rodriguez
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA 71130
| | - Ronald Maloney
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA 71130
| | | | - Tak Yee Aw
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA 71130
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Epidermal growth factor- and stress-induced loss of gap junctional communication is mediated by ERK-1/ERK-2 but not ERK-5 in rat liver epithelial cells. Biochem Biophys Res Commun 2007; 364:313-7. [DOI: 10.1016/j.bbrc.2007.09.132] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2007] [Accepted: 09/28/2007] [Indexed: 11/17/2022]
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18
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von Montfort C, Fernau NS, Beier JI, Sies H, Klotz LO. Extracellular generation of hydrogen peroxide is responsible for activation of EGF receptor by ultraviolet A radiation. Free Radic Biol Med 2006; 41:1478-87. [PMID: 17023275 DOI: 10.1016/j.freeradbiomed.2006.08.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2005] [Revised: 07/10/2006] [Accepted: 08/08/2006] [Indexed: 11/30/2022]
Abstract
Receptor tyrosine kinases such as the epidermal growth factor receptor (EGFR) have been proposed to be activated in cells exposed to ultraviolet A (UVA) radiation (320-400 nm) and to be involved in photocarcinogenesis. Singlet oxygen and hydrogen peroxide are being discussed as mediators of the activation of signal transduction pathways by UVA. It is demonstrated here that EGFR is not activated in cells exposed to UVA in the absence of extracellular photosensitizers. Rather, UVA was capable of activating the EGFR and the related ErbB2 receptor tyrosine kinase in HeLa cells and human keratinocytes only under conditions that allowed for the extracellular photochemical generation of H(2)O(2), such as when cells were covered with cell culture medium during exposure to UVA. Pretreatment of cells with vanadate was required for UVA-induced EGFR activation, pointing to the involvement of protein tyrosine phosphatases. Unlike H(2)O(2), photochemically generated singlet oxygen did not activate EGFR but instead impaired the activation of EGFR by its ligand, EGF. In summary, extracellularly generated H(2)O(2) mediates UVA-induced activation of the EGFR and of ErbB2, whereas intracellular generation of reactive oxygen species upon exposure of cells to UVA is not sufficient for activation of the receptor.
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Affiliation(s)
- Claudia von Montfort
- Institut für Biochemie und Molekularbiologie I, Heinrich-Heine-Universität Düsseldorf, D-40225 Düsseldorf, Germany
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19
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Beier JI, von Montfort C, Sies H, Klotz LO. Activation of ErbB2 by 2-methyl-1,4-naphthoquinone (menadione) in human keratinocytes: role of EGFR and protein tyrosine phosphatases. FEBS Lett 2006; 580:1859-64. [PMID: 16516204 DOI: 10.1016/j.febslet.2006.02.048] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2005] [Revised: 01/27/2006] [Accepted: 02/16/2006] [Indexed: 12/19/2022]
Abstract
Activation of ErbB receptor tyrosine kinases triggers multiple signaling pathways that regulate cellular proliferation and survival. We here demonstrate that ErbB2 is activated via the epidermal growth factor receptor (EGFR) upon exposure of cultured human keratinocytes to 2-methyl-1,4-naphthoquinone (menadione). Both ErbB2 and EGFR are shown to be regulated by protein tyrosine phosphatases that are inhibited by menadione, giving rise to the hypothesis that phosphatase inhibition by menadione may result in a net activation of EGFR and an enhanced ErbB2 phosphorylation. Isolated PTP-1B, a protein tyrosine phosphatase known to be associated with ErbB receptors, is demonstrated to be inhibited by menadione.
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Affiliation(s)
- Juliane I Beier
- Institut für Biochemie und Molekularbiologie I, Heinrich-Heine-Universität Düsseldorf, Universitätsstr. 1, Geb. 22.03; D-40225 Düsseldorf, Germany
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20
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Barthel A, Klotz LO. Phosphoinositide 3-kinase signaling in the cellular response to oxidative stress. Biol Chem 2005; 386:207-16. [PMID: 15843166 DOI: 10.1515/bc.2005.026] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Oxidative stress is linked to the pathogenesis and pathobiochemistry of various diseases, including cancer, diabetes and cardiovascular disorders. The non-specific damaging effect of reactive oxygen species (ROS) generated during oxidative stress is involved in the development of diseases, as well as the activation of specific signaling cascades in cells exposed to the higher oxidant load. A cellular signaling cascade that is activated by several types of reactive oxygen species is the phosphoinositide 3'-kinase (PI 3-kinase)/protein kinase B (PKB) pathway, which regulates cellular survival and fuel metabolism, thus establishing a link between oxidative stress and signaling in neoplastic, metabolic or degenerative diseases. Several links of PI 3-kinase/PKB signaling to ROS are discussed in this review, with particular focus on the molecular mechanisms involved in the regulation of PI 3-kinase signaling by oxidative stress and important players such as (i) the glutathione and glutaredoxin system, (ii) the thioredoxin system and (iii) Ser/Thr- and Tyr phosphatases.
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Affiliation(s)
- Andreas Barthel
- Abteilung für Endokrinologie, Diabetologie und Rheumatologie, Heinrich-Heine-Universität Düsseldorf, D-40225 Düsseldorf, Germany
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21
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Abdelmohsen K, von Montfort C, Stuhlmann D, Gerber PA, Decking UKM, Sies H, Klotz LO. Doxorubicin induces EGF receptor-dependent downregulation of gap junctional intercellular communication in rat liver epithelial cells. Biol Chem 2005; 386:217-23. [PMID: 15843167 DOI: 10.1515/bc.2005.027] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Exposure of rat liver epithelial cells to doxorubicin, an anthraquinone derivative widely employed in cancer chemotherapy, led to a dose-dependent decrease in gap junctional intercellular communication (GJC). Gap junctions are clusters of inter-cellular channels consisting of connexins, the major connexin in the cells used being connexin-43 (Cx43). Doxorubicin-induced loss of GJC was mediated by activation of extracellular signal-regulated kinase (ERK)-1 and ERK-2, as demonstrated using inhibitors of ERK activation. Furthermore, activation of the epidermal growth factor (EGF) receptor by doxorubicin was responsible for ERK activation and the subsequent attenuation of GJC. Inhibition of GJC, however, was not by direct phosphorylation of Cx43 by ERK-1/2, whereas menadione, a 1,4-naphthoquinone derivative that was previously demonstrated to activate the same EGF receptor-dependent pathway as doxorubicin, resulting in downregulation of GJC, caused strong phos-phorylation of Cx43 at serines 279 and 282. Thus, ERK-dependent downregulation of GJC upon exposure to quinones may occur both by direct phosphorylation of Cx43 and in a phosphorylation-independent manner.
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Affiliation(s)
- Kotb Abdelmohsen
- Institut für Biochemie und Molekularbiologie I, Heinrich-Heine-Universität Düsseldorf, D-40225 Düsseldorf, Germany
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22
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Abdelmohsen K, Stuhlmann D, Daubrawa F, Klotz LO. Dicumarol is a potent reversible inhibitor of gap junctional intercellular communication. Arch Biochem Biophys 2005; 434:241-7. [PMID: 15639223 DOI: 10.1016/j.abb.2004.11.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2004] [Revised: 10/27/2004] [Indexed: 11/19/2022]
Abstract
Dicumarol [3,3'-methylene-bis(4-hydroxycoumarin)] is a potent inhibitor of NAD(P)H:quinone oxidoreductase-1. Exposure of rat liver epithelial cells or of human skin fibroblasts to dicumarol resulted in a rapid and complete inhibition of connexin-43-dependent gap junctional intercellular communication (GJC). GJC was restored within 60min following removal of dicumarol. The concentration of dicumarol required for half maximal inhibition of GJC was 3muM, making dicumarol about 10-fold more effective in blocking GJC than 1-octanol and flufenamic acid, known inhibitors of GJC. Warfarin, a related coumarin derivative, also attenuated GJC, yet very high concentrations of 5-10mM were required. Dicumarol-induced downregulation of GJC was found not to be due to an interference with pathways enhancing the phosphorylation of connexin-43, such as epidermal growth factor receptor and extracellular signal-regulated kinase pathways. Rather, inhibition of GJC by dicumarol was paralleled by a reversible loss of a phosphorylated form ("P2") of connexin-43.
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Affiliation(s)
- Kotb Abdelmohsen
- Institut für Biochemie und Molekularbiologie I, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
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23
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Melchheier I, von Montfort C, Stuhlmann D, Sies H, Klotz LO. Quinone-induced Cdc25A inhibition causes ERK-dependent connexin phosphorylation. Biochem Biophys Res Commun 2005; 327:1016-23. [PMID: 15652497 DOI: 10.1016/j.bbrc.2004.12.107] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2004] [Indexed: 01/08/2023]
Abstract
Gap junctional intercellular communication (GJC) varies during progression of the cell cycle. We propose here that Cdc25A, a dual specificity phosphatase crucial for cell cycle progression, is linked to connexin (Cx) phosphorylation and the modulation of GJC. Inhibition of Cdc25 phosphatases in rat liver epithelial cells employing a 1,4-naphthoquinone-based inhibitor, NSC95397, induced cell cycle arrest, tyrosine phosphorylation of the epidermal growth factor receptor (EGFR), and activation of extracellular signal-regulated kinases ERK-1 and -2. ERK activation was blocked by specific inhibitors of MAPK/ERK kinases 1/2 or of the EGFR tyrosine kinase. An EGFR-dephosphorylation assay suggested that Cdc25A interacts with the EGFR, with inhibition by NSC95397 resulting in activation of the receptor. As a consequence of ERK activation, Cx43 was phosphorylated, resulting in a downregulation of GJC. Loss of GJC was prevented by inhibition of ERK activation. In summary, cell cycle and GJC are connected via Cdc25A and the EGFR-ERK pathway.
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Affiliation(s)
- Ira Melchheier
- Institut für Biochemie und Molekularbiologie I, Heinrich-Heine-Universität Düsseldorf, D-40225 Düsseldorf, Germany
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