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Christensen SB, Simonsen HT, Engedal N, Nissen P, Møller JV, Denmeade SR, Isaacs JT. From Plant to Patient: Thapsigargin, a Tool for Understanding Natural Product Chemistry, Total Syntheses, Biosynthesis, Taxonomy, ATPases, Cell Death, and Drug Development. PROGRESS IN THE CHEMISTRY OF ORGANIC NATURAL PRODUCTS 2021; 115:59-114. [PMID: 33797641 DOI: 10.1007/978-3-030-64853-4_2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Thapsigargin, the first representative of the hexaoxygenated guaianolides, was isolated 40 years ago in order to understand the skin-irritant principles of the resin of the umbelliferous plant Thapsia garganica. The pronounced cytotoxicity of thapsigargin is caused by highly selective inhibition of the intracellular sarco-endoplasmic Ca2+-ATPase (SERCA) situated on the membrane of the endo- or sarcoplasmic reticulum. Thapsigargin is selective to the SERCA pump and to a minor extent the secretory pathway Ca2+/Mn2+ ATPase (SPCA) pump. Thapsigargin has become a tool for investigation of the importance of SERCA in intracellular calcium homeostasis. In addition, complex formation of thapsigargin with SERCA has enabled crystallization and structure determination of calcium-free states by X-ray crystallography. These results led to descriptions of the mechanism of action and kinetic properties of SERCA and other ATPases. Inhibition of SERCA depletes Ca2+ from the sarco- and endoplasmic reticulum provoking the unfolded protein response, and thereby has enabled new studies on the mechanism of cell death. Development of protocols for selective transformation of thapsigargin disclosed the chemistry and facilitated total synthesis of the molecule. Conversion of trilobolide into thapsigargin offered an economically feasible sustainable source of thapsigargin, which enables a future drug production. Principles for prodrug development were used by conjugating a payload derived from thapsigargin with a hydrophilic peptide selectively cleaved by proteases in the tumor. Mipsagargin was developed in order to obtain a drug for treatment of cancer diseases characterized by the presence of prostate specific membrane antigen (PSMA) in the neovascular tissue of the tumors. Even though mipsagargin showed interesting clinical effects the results did not encourage funding and consequently the attempt to register the drug has been abandoned. In spite of this disappointing fact, the research performed to develop the drug has resulted in important scientific discoveries concerning the chemistry, biosynthesis and biochemistry of sesquiterpene lactones, the mechanism of action of ATPases including SERCA, mechanisms for cell death caused by the unfolded protein response, and the use of prodrugs for cancer-targeting cytotoxins. The presence of toxins in only some species belonging to Thapsia also led to a major revision of the taxonomy of the genus.
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Affiliation(s)
- Søren Brøgger Christensen
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, 2100, Copenhagen Ø, Denmark.
| | - Henrik Toft Simonsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, Bld 223, 2800, Kgs. Lyngby, Denmark
| | - Nikolai Engedal
- Department of Tumor Biology, Institute for Cancer Research, University Hospital, Montebello, 0379, Oslo, Norway
| | - Poul Nissen
- Department of Molecular Biology and Genetics, Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Gustav Wieds Vej 10C, 8000, Aarhus C, Denmark
| | - Jesper Vuust Møller
- Department of Biomedicine, Aarhus University, Ole Worms Allé 3, Bld 1182, Room 114, 8000, Aarhus C, Denmark
| | - Samuel R Denmeade
- Department of Oncology, Prostate Cancer Program, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins Maryland, The Johns Hopkins University School of Medicine, Baltimore, The Bunting-Blaustein Cancer Research Building, 1650 Orleans Street, Baltimore, MD, 21231, USA
| | - John T Isaacs
- Department of Oncology, Prostate Cancer Program, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins Maryland, The Johns Hopkins University School of Medicine, Baltimore, The Bunting-Blaustein Cancer Research Building, 1650 Orleans Street, Baltimore, MD, 21231, USA
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Abstract
CFTR protein is an ion channel regulated by cAMP-dependent phosphorylation and expressed in many types of epithelial cells. CFTR-mediated chloride and bicarbonate secretion play an important role in the respiratory and gastrointestinal systems. Pharmacological modulators of CFTR represent promising drugs for a variety of diseases. In particular, correctors and potentiators may restore the activity of CFTR in cystic fibrosis patients. Potentiators are also potentially useful to improve mucociliary clearance in patients with chronic obstructive pulmonary disease. On the other hand, CFTR inhibitors may be useful to block fluid and electrolyte loss in secretory diarrhea and slow down the progression of polycystic kidney disease.
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Affiliation(s)
- Olga Zegarra-Moran
- U.O.C. Genetica Medica, Istituto Giannina Gaslini, Via Gerolamo Gaslini 5, 16147, Genoa, Italy
| | - Luis J V Galietta
- U.O.C. Genetica Medica, Istituto Giannina Gaslini, Via Gerolamo Gaslini 5, 16147, Genoa, Italy.
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The involvement of mitochondrial apoptotic pathway in eugenol-induced cell death in human glioblastoma cells. Toxicol Lett 2015; 232:122-32. [DOI: 10.1016/j.toxlet.2014.10.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 09/30/2014] [Accepted: 10/15/2014] [Indexed: 12/27/2022]
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Chien CS, Ma KH, Lee HS, Liu PS, Li YH, Huang YS, Chueh SH. Dual effect of capsaicin on cell death in human osteosarcoma G292 cells. Eur J Pharmacol 2013; 718:350-60. [PMID: 24012930 DOI: 10.1016/j.ejphar.2013.08.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 07/23/2013] [Accepted: 08/24/2013] [Indexed: 12/11/2022]
Abstract
Thirty percent of osteosarcoma patients die within 5 years. New agents that induce apoptosis of osteosarcoma cells might be therapeutically useful. Here, we characterized the apoptotic mechanism induced by capsaicin in G292 osteosarcoma cells. Our results show that capsaicin induces an increase in the cytosolic Ca(2+) concentration which is independent of the extracellular Ca(2+) concentration and depletes intracellular Ca(2+) stores, suggesting the presence of endoplasmic reticulum transient receptor potential vanilloid receptor type 1. Capsaicin also activates the mitochondrial caspase 3-dependent death cascade. Rapamycin, an inhibitor of mammalian target of rapamycin, evokes autophagy, as do capsaicin or thapsigargin, a sarco(endo)plasmic reticulum Ca(2+) ATPase inhibitor that causes Ca(2+) store depletion. Capsaicin-induced cell death is completely inhibited by co-treatment with the pan-caspase inhibitor Z-VAD-fmk and increased by the autophagy inhibitor 3-methyladenine, suggesting the existence of an autophagy-dependent anti-apoptotic mechanism. Capsaicin also induces ERK phosphorylation, which acts as a downstream effector of autophagy. 3-Methyladenine or PD98059, an ERK kinase inhibitor, restores capsaicin-induced cell death in the presence of Z-VAD-fmk, suggesting that inhibition of autophagy activates a second cell death pathway that is caspase-independent. Taken together, our data show that capsaicin causes Ca(2+) depletion of intracellular Ca(2+) stores and simultaneously activates the mitochondrial caspase-dependent death cascade and autophagy-dependent ERK activation and that the latter counteracts a second death signaling pathway that is caspase-independent.
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Affiliation(s)
- Chi-Sheng Chien
- Department of Orthopaedics, Chi Mei Medical Center, Tainan, Taiwan, ROC.
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Dubois C, Vanden Abeele F, Sehgal P, Olesen C, Junker S, Christensen SB, Prevarskaya N, Møller JV. Differential effects of thapsigargin analogues on apoptosis of prostate cancer cells: complex regulation by intracellular calcium. FEBS J 2013; 280:5430-40. [PMID: 23927406 DOI: 10.1111/febs.12475] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Revised: 07/16/2013] [Accepted: 07/19/2013] [Indexed: 01/28/2023]
Abstract
The inhibition of sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) by thapsigargin (Tg) and Tg-type analogues is considered to trigger cell death by activation of apoptotic pathways. Some of these analogues may be useful as antineoplastic agents after appropriate targeting as peptide conjugated prodrugs to cancer cells. With this in mind, this study evaluates the effect on LNCaP androgen-sensitive cancer cells of thapsigargin substituted with 12-aminododecanoyl linkers and Leu (Leu-8ADT), aspartate (Asp-8ADT) or Boc-8ADT. Our results show that both Leu-8ADT and Asp-8ADT result in rapid ER calcium depletion and an influx of calcium across the plasma membrane by activation of store-operated calcium entry. By contrast, ER Ca(2+) depletion by Boc-8ADT is a very slow process that does not perceptibly increase cytosolic Ca(2+) and activate store-operated calcium entry, because the inhibition of SERCA with this compound is very slow. Nevertheless, we find that Boc-8ADT is a more efficient inducer of apoptosis than both Tg and Leu-8ADT. Compared with Tg and the other analogues, apoptosis induced by Asp-8ADT is very modest, although this compound also activates store-operated calcium entry and at high concentrations (1 μm) causes severe morphological changes, reflecting decreased cell viability. We conclude that many factors need to be considered for optimization of these compounds in antineoplastic drug design. Among these ER stress induced by Ca(2+) endoplasmic reticulum mobilization seems particularly important, whereas the early cytosolic increase of Ca(2+) concentration preceding the executive phase of apoptosis appears to be of no, or little, consequence for a subsequent apoptotic effect.
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Affiliation(s)
- Charlotte Dubois
- Inserm U1003, Equipe labellisée par la Ligue Nationale Contre le Cancer, Université des Sciences et Technologies de Lille (USTL), Villeneuve d'Ascq, France; Center for Membrane Pumps in Cells and Diseases, Danish Research Foundation, Aarhus, Denmark
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Wang XG, Tao J, Ma MM, Tang YB, Zhou JG, Guan YY. Tyrosine 284 phosphorylation is required for ClC-3 chloride channel activation in vascular smooth muscle cells. Cardiovasc Res 2013; 98:469-78. [DOI: 10.1093/cvr/cvt063] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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Acute phorbol ester treatment inhibits thapsigargin-induced cell death in porcine aortic smooth muscle cells. Eur J Pharmacol 2012; 686:8-15. [DOI: 10.1016/j.ejphar.2012.04.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Revised: 04/04/2012] [Accepted: 04/05/2012] [Indexed: 12/11/2022]
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Chen M, Chen TS, Lu YY, Liu CY, Qu JL. Dihydroarteminsin-induced apoptosis is not dependent on the translocation of Bim to the endoplasmic reticulum in human lung adenocarcinoma cells. Pathol Oncol Res 2012; 18:809-16. [PMID: 22391963 DOI: 10.1007/s12253-012-9508-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Accepted: 02/16/2012] [Indexed: 01/03/2023]
Abstract
Bim, a proapoptotic BH3-only member of Bcl-2 family, has been considered to play an important role in initiating mitochondrial apoptotic pathway. Our previous studies have shown the ability of dihydroarteminsin (DHA) to induce apoptosis in human lung adenocarcinoma (ASTC-a-1) cells. In this study, we investigated the function of Bim during DHA-induced apoptosis in ASTC-a-1 and another human lung adenocarcinoma (A549) cell lines. Confocal imaging of single living cell expressing GFP-BimL showed the translocation of Bim to endoplasmic reticulum (ER) rather than mitochondria during DHA-induced apoptosis. Moreover, we also found that DHA induced ER stress and an increase of Bim protein levels. However, silencing Bim by short hairpin RNA did not inhibit DHA-induced caspase-9 activation and cell apoptosis. Taken together, our results demonstrate for the first time that DHA induces Bim translocation to ER, but DHA-induced apoptosis is not dependent on Bim in ASTC-a-1 and A549 cell lines.
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Affiliation(s)
- Min Chen
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, South China Normal University, Guangzhou, 510631, China
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Liu YM, Wang X, Nawaz A, Kong ZH, Hong Y, Wang CH, Zhang JJ. Wogonin ameliorates lipotoxicity-induced apoptosis of cultured vascular smooth muscle cells via interfering with DAG-PKC pathway. Acta Pharmacol Sin 2011; 32:1475-82. [PMID: 21986573 DOI: 10.1038/aps.2011.120] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
AIM To investigate the effects of wogonin (5,7-dihydroxy-8-methoxyflavone) extracted from Scutellaria baicalensis Georgi (S baicalensis) on lipotoxicity-induced apoptosis of vascular smooth muscle cells (VSMCs) and the underlying mechanisms. METHODS Cultured VSMCs were used. Apoptosis of VSMCs was induced by palmitate (0.75 mmol/L), and detected using TUNEL assay. The expression levels of protein and phosphorylated protein were measured using Western blot analysis. RESULTS Treatment of VSMCs with wogonin (10, 25 and 50 μmol/L) significantly attenuated the apoptosis and endoplasmic reticulum (ER) stress induced by palmitate in concentration- and time-dependent manners. Wogonin (50 μmol/L) decreased palmitate-induced reactive oxygen species (ROS) generation. The ER stress inhibitor 4-phenyl butyric acid (5 mmol/L) significantly decreased palmitate-induced apoptotic cells, and occluded the anti-apoptotic effect of wogonin (25 μmol/L). Wogonin (10, 25 and 50 μmol/L) significantly reduced the intracellular diacylglycerol (DAG) accumulation and expression levels of phosphorylated PKCs in palmitate-treated VSMCs. CONCLUSION Our results suggest that wogonin inhibits lipotoxicity-induced apoptosis of VSMCs via suppressing the intracellular DAG accumulation and subsequent inhibition of PKC phosphorylation. Wogonin has therapeutic potential for the prevention and treatment of atherosclerosis.
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Sutendra G, Dromparis P, Wright P, Bonnet S, Haromy A, Hao Z, McMurtry MS, Michalak M, Vance JE, Sessa WC, Michelakis ED. The role of Nogo and the mitochondria-endoplasmic reticulum unit in pulmonary hypertension. Sci Transl Med 2011; 3:88ra55. [PMID: 21697531 DOI: 10.1126/scitranslmed.3002194] [Citation(s) in RCA: 184] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Pulmonary arterial hypertension (PAH) is caused by excessive proliferation of vascular cells, which occlude the lumen of pulmonary arteries (PAs) and lead to right ventricular failure. The cause of the vascular remodeling in PAH remains unknown, and the prognosis of PAH remains poor. Abnormal mitochondria in PAH PA smooth muscle cells (SMCs) suppress mitochondria-dependent apoptosis and contribute to the vascular remodeling. We hypothesized that early endoplasmic reticulum (ER) stress, which is associated with clinical triggers of PAH including hypoxia, bone morphogenetic protein receptor II mutations, and HIV/herpes simplex virus infections, explains the mitochondrial abnormalities and has a causal role in PAH. We showed in SMCs from mice that Nogo-B, a regulator of ER structure, was induced by hypoxia in SMCs of the PAs but not the systemic vasculature through activation of the ER stress-sensitive transcription factor ATF6. Nogo-B induction increased the distance between the ER and mitochondria and decreased ER-to-mitochondria phospholipid transfer and intramitochondrial calcium. In addition, we noted inhibition of calcium-sensitive mitochondrial enzymes, increased mitochondrial membrane potential, decreased mitochondrial reactive oxygen species, and decreased mitochondria-dependent apoptosis. Lack of Nogo-B in PASMCs from Nogo-A/B-/- mice prevented these hypoxia-induced changes in vitro and in vivo, resulting in complete resistance to PAH. Nogo-B in the serum and PAs of PAH patients was also increased. Therefore, triggers of PAH may induce Nogo-B, which disrupts the ER-mitochondria unit and suppresses apoptosis. This could rescue PASMCs from death during ER stress but enable the development of PAH through overproliferation. The disruption of the ER-mitochondria unit may be relevant to other diseases in which Nogo is implicated, such as cancer or neurodegeneration.
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Affiliation(s)
- Gopinath Sutendra
- Department of Medicine, University of Alberta, Edmonton, Alberta T6G 2B7, Canada
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Adão-Novaes J, Guterres CDCB, da Silva AGLS, Campello-Costa P, Linden R, Sholl-Franco A. Interleukin-4 blocks thapsigargin-induced cell death in rat rod photoreceptors: involvement of cAMP/PKA pathway. J Neurosci Res 2009; 87:2167-74. [PMID: 19235892 DOI: 10.1002/jnr.22026] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Although the photoreceptors cell death is the main cause of some retinopathies diseases, the mechanisms involved in this process are poorly understood. The neuroprotective effects of interleukin-4 (IL-4) have been shown in several tissues, including retina. We demonstrate that treatment of rat retinal explants with IL-4 completely inhibited the thapsigargin-induced rod photoreceptor cell death after 24 hr in culture. We also showed that IL-4 receptor alpha subunit (IL-4Ralpha) is abundantly present in retina. Colocalization of IL-4Ralpha and rhodopsin indicate a direct effect of this cytokine in rod photoreceptor cells. Moreover, IL-4 increased the intracellular levels of cAMP in 7.4-fold, indicating that the neuroprotective effect of this cytokine was completely blocked by RpcAMP, an inhibitor of protein kinase (PKA). Our data demonstrate, for the first time, the neuroprotective effect of IL-4 through cAMP/PKA pathway in thapsigargin-induced photoreceptor cell death.
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Affiliation(s)
- Juliana Adão-Novaes
- Programa de Neurobiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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Luciani A, Villella VR, Vasaturo A, Giardino I, Raia V, Pettoello-Mantovani M, D'Apolito M, Guido S, Leal T, Quaratino S, Maiuri L. SUMOylation of tissue transglutaminase as link between oxidative stress and inflammation. THE JOURNAL OF IMMUNOLOGY 2009; 183:2775-84. [PMID: 19625650 DOI: 10.4049/jimmunol.0900993] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Cystic fibrosis (CF) is a monogenic disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. CF is characterized by chronic bacterial lung infections and inflammation, and we have previously reported that tissue transglutaminase (TG2), a multifunctional enzyme critical to several diseases, is constitutively up-regulated in CF airways and drives chronic inflammation. Here, we demonstrate that the generation of an oxidative stress induced by CFTR-defective function leads to protein inhibitor of activated STAT (PIAS)y-mediated TG2 SUMOylation and inhibits TG2 ubiquitination and proteasome degradation, leading to sustained TG2 activation. This prevents peroxisome proliferator-activated receptor (PPAR)gamma and IkBalpha SUMOylation, leading to NF-kappaB activation and to an uncontrolled inflammatory response. Cellular homeostasis can be restored by small ubiquitin-like modifier (SUMO)-1 or PIASy gene silencing, which induce TG2 ubiquitination and proteasome degradation, restore PPARgamma SUMOylation, and prevent IkBalpha cross-linking and degradation, thus switching off inflammation. Manganese superoxide dismutase overexpression as well as the treatment with the synthetic superoxide dismutase mimetic EUK-134 control PIASy-TG2 interaction and TG2 SUMOylation. TG2 inhibition switches off inflammation in vitro as well as in vivo in a homozygous F508del-CFTR mouse model. Thus, TG2 may function as a link between oxidative stress and inflammation by driving the decision as to whether a protein should undergo SUMO-mediated regulation or degradation. Targeting TG2-SUMO interactions might represent a new option to control disease evolution in CF patients as well as in other chronic inflammatory diseases, neurodegenerative pathologies, and cancer.
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Dannhoffer L, Blouquit-Laye S, Regnier A, Chinet T. Functional Properties of Mixed Cystic Fibrosis and Normal Bronchial Epithelial Cell Cultures. Am J Respir Cell Mol Biol 2009; 40:717-23. [DOI: 10.1165/rcmb.2008-0018oc] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Protective effect of paraoxonase-2 against endoplasmic reticulum stress-induced apoptosis is lost upon disturbance of calcium homoeostasis. Biochem J 2009; 416:395-405. [PMID: 18691157 DOI: 10.1042/bj20080775] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
PON2 (paraoxonase-2) is a ubiquitously expressed antioxidative protein which is largely found in the ER (endoplasmic reticulum). Addressing the cytoprotective functions of PON2, we observed that PON2 overexpression provided significant resistance to ER-stress-induced caspase 3 activation when the ER stress was induced by interference with protein modification (by tunicamycin or dithiothreitol), but not when ER stress was induced by disturbance of Ca(2+) homoeostasis (by thapsigargin or A23187). When analysing the underlying molecular events, we found an activation of the PON2 promoter in response to all tested ER-stress-inducing stimuli. However, only tunicamycin and dithiothreitol resulted in increased PON2 mRNA and protein levels. In contrast, when ER stress was caused by thapsigargin or A23187, we observed a Ca(2+)-dependent active degradation of PON2 mRNA, elicited by its 5'-untranslated region. In addition, thapsigargin and A23187 also induced PON2 protein degradation by a Ca(2+)-dependent calpain-mediated mechanism. Thus we provide evidence that independent mechanisms mediate the degradation of PON2 mRNA and protein after disturbance of Ca(2+) homoeostasis. Furthermore, because Ca(2+)-disturbance induces ER stress, but abrogates the otherwise protective function of PON2 against ER-stress-induced apoptosis, we propose that the underlying cause of ER stress determines the efficacy of putative cellular defence mechanisms.
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Chang HC, Huang CC, Huang CJ, Cheng JS, Liu SI, Tsai JY, Chang HT, Huang JK, Chou CT, Jan CR. Desipramine-induced apoptosis in human PC3 prostate cancer cells: Activation of JNK kinase and caspase-3 pathways and a protective role of [Ca2+]i elevation. Toxicology 2008; 250:9-14. [DOI: 10.1016/j.tox.2008.05.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Revised: 05/15/2008] [Accepted: 05/15/2008] [Indexed: 10/22/2022]
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Maiuri L, Luciani A, Giardino I, Raia V, Villella VR, D'Apolito M, Pettoello-Mantovani M, Guido S, Ciacci C, Cimmino M, Cexus ON, Londei M, Quaratino S. Tissue transglutaminase activation modulates inflammation in cystic fibrosis via PPARgamma down-regulation. THE JOURNAL OF IMMUNOLOGY 2008; 180:7697-705. [PMID: 18490773 DOI: 10.4049/jimmunol.180.11.7697] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Cystic fibrosis (CF), the most common life-threatening inherited disease in Caucasians, is due to mutations in the CF transmembrane conductance regulator (CFTR) gene and is characterized by airways chronic inflammation and pulmonary infections. The inflammatory response is not secondary to the pulmonary infections. Indeed, several studies have shown an increased proinflammatory activity in the CF tissues, regardless of bacterial infections, because inflammation is similarly observed in CFTR-defective cell lines kept in sterile conditions. Despite recent studies that have indicated that CF airway epithelial cells can spontaneously initiate the inflammatory cascade, we still do not have a clear insight of the molecular mechanisms involved in this increased inflammatory response. In this study, to understand these mechanisms, we investigated ex vivo cultures of nasal polyp mucosal explants of CF patients and controls, CFTR-defective IB3-1 bronchial epithelial cells, C38 isogenic CFTR corrected, and 16HBE normal bronchial epithelial cell lines. We have shown that a defective CFTR induces a remarkable up-regulation of tissue transglutaminase (TG2) in both tissues and cell lines. The increased TG2 activity leads to functional sequestration of the anti-inflammatory peroxisome proliferator-activated receptor gamma and increase of the classic parameters of inflammation, such as TNF-alpha, tyrosine phosphorylation, and MAPKs. Specific inhibition of TG2 was able to reinstate normal levels of peroxisome proliferator-activated receptor-gamma and dampen down inflammation both in CF tissues and CFTR-defective cells. Our results highlight an unpredicted central role of TG2 in the mechanistic pathway of CF inflammation, also opening a possible new wave of therapies for sufferers of chronic inflammatory diseases.
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Affiliation(s)
- Luigi Maiuri
- European Institute for Cystic Fibrosis Research, San Raffaele Scientific Institute, Milan, Italy
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Claro S, Oshiro MEM, Freymuller E, Katchburian E, Kallas EG, Cerri PS, Ferreira AT. Gamma-radiation induces apoptosis via sarcoplasmatic reticulum in guinea pig ileum smooth muscle cells. Eur J Pharmacol 2008; 590:20-8. [PMID: 18582867 DOI: 10.1016/j.ejphar.2008.05.038] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2007] [Revised: 04/25/2008] [Accepted: 05/19/2008] [Indexed: 10/22/2022]
Abstract
We investigated the effects of gamma-radiation on cells isolated from the longitudinal smooth muscle layer of the guinea pig ileum, a relatively radioresistant tissue. Single doses (up to 50 Gy) reduced the amount of sarcoplasmatic reticulum and condensed the myofibrils, as shown by electron microscopy 3 days post-irradiation. After that, contractility of smooth muscle strips was reduced. Ca(2+) handling was altered after irradiation, as shown in fura-2 loaded cells, with elevated basal intracellular Ca(2+), reduced amount of intrareticular Ca(2+), and reduced capacitive Ca(2+) entry. Radiation also induced apoptosis, judged from flow cytometry of cells loaded with proprium iodide. Electron microscopy showed that radiation caused condensation of chromatin in dense masses around the nuclear envelope, the presence of apoptotic bodies, fragmentation of the nucleus, detachment of cells from their neighbors, and reductions in cell volume. Radiation also caused activation of caspase 12. Apoptosis was reduced by the administration of the caspase inhibitor Z-Val-Ala-Asp-fluoromethyl-ketone methyl ester (Z-VAD-FMK) during the 3 day period after irradiation, and by the chelator of intracellular Ca(2+), 1,2-bis(o-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid (BAPTA), from 1 h before until 2 h after irradiation. BAPTA also reduced the effects of radiation on contractility, basal intracellular Ca(2+), amount of intrareticular Ca(2+), capacitative Ca(2+) entry, and apoptosis. In conclusion, the effects of gamma radiation on contractility, Ca(2+) handling, and apoptosis appear due to a toxic action of intracellular Ca(2+). Ca(2+)-induced damage to the sarcoplasmatic reticulum seems a key event in impaired Ca(2+) handling and apoptosis induced by gamma-radiation.
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Affiliation(s)
- Sandra Claro
- Department of Biophysics, Federal University of São Paulo (UNIFESP-EPM), São Paulo, SP, Brazil.
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Tehrani OS, Douglas KA, Lawhorn-Crews JM, Shields AF. Tracking cellular stress with labeled FMAU reflects changes in mitochondrial TK2. Eur J Nucl Med Mol Imaging 2008; 35:1480-8. [PMID: 18265975 DOI: 10.1007/s00259-008-0738-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2007] [Accepted: 01/22/2008] [Indexed: 12/31/2022]
Abstract
PURPOSE Fluoropyrimidines like 1-(2'-deoxy-2'-fluoro-beta-D: -arabinofuranosyl)-thymine (FMAU) and 3'-deoxy-3'-fluorothymidine (FLT) accumulate in tumors and are being used as positron emission tomography tumor-imaging tracers. Proliferating tissues with high thymidine kinase 1 (TK1) activity retain FLT; however, the mechanism of selective accumulation of FMAU in tumors and certain other tissues requires further study. METHODS Retention of [(3)H]FLT and [(3)H]FMAU was measured in prostate cancer cell lines PC3, LNCaP, DU145, and the breast cancer cell line MD-MBA-231, and the tracer metabolites were analyzed by high-performance liquid chromatography (HPLC). FMAU retention, thymidine kinase 2 (TK2) activity, and mitochondrial mass were determined in cells stressed by depleted cell culture medium or by treating with oxidative, reductive, and energy stress, or specific adenosine monophosphate-activated protein kinase activator, or eIF2 inhibitor. TK1 and TK2 activities and mitochondrial mass were determined by FLT phosphorylation, 1-beta-D: -arabinofuranosylthymine (Ara-T) phosphorylation, and flow cytometry, respectively. RESULTS FMAU retention in rapidly proliferating cancer cell lines was five to ten times lower than FLT after 10 min incubation. HPLC analysis of the cellular extracts showed that phosphorylated tracers are the main retained metabolites. Nutritional stress decreased TK1 activity and FLT retention but increased retained FMAU. TK2 inhibition decreased FMAU retention and phosphorylation with negligible effects on FLT. Oxidative, reductive, or energy stress increased FMAU retention and correlated with mitochondrial mass (r (2) = 0.88, p = 0.006). FMAU phosphorylation correlated with increased TK2 activity (r (2) = 0.87, p = 0.0002). CONCLUSION FMAU is preferably phosphorylated by TK2 and can track TK2 activity and mitochondrial mass in cellular stress. FMAU may provide an early marker of treatment effects.
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Affiliation(s)
- Omid S Tehrani
- Karmanos Cancer Institute, Wayne State University, 4100 John R, 4 HWCRC, Detroit, MI 48201-2013, USA
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