1
|
Somasundaram DB, Manokaran K, Selvanesan BC, Bhaskaran RS. Impact of di-(2-ethylhexyl) phthalate on the uterus of adult Wistar rats. Hum Exp Toxicol 2016; 36:565-572. [DOI: 10.1177/0960327116657601] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Di-(2-ethylhexyl) phthalate (DEHP) is the most common plasticizer used in polyvinyl chloride-based plastics. DEHP is not covalently bound to the plastics and is easily released to the environment, resulting in human exposure. In this study, the adult rats were exposed to DEHP and its effects on the uterus was evaluated. Healthy adult female rats were treated with DEHP orally (with dose level 0, 1, 10, and 100 mg/kg body weight/day) for 30 days. No significant changes in the body weight and wet uterine weight were observed. Ovarian hormones and their receptor levels in the uterus were increased. Histological studies exhibited the structural abnormalities such as decrease in diameter, thinning of the layers and disruption in the glandular epithelium.
Collapse
Affiliation(s)
- DB Somasundaram
- Department of Endocrinology, University of Madras, Institute of Basic Medical Sciences
| | - K Manokaran
- School of Allied Health Sciences, Manipal University, Manipal, Karnataka, India
| | - BC Selvanesan
- Department of Endocrinology, University of Madras, Institute of Basic Medical Sciences
| | - RS Bhaskaran
- Department of Endocrinology, University of Madras, Institute of Basic Medical Sciences
| |
Collapse
|
2
|
HUBER SOPHIE, VALENTE SERGIO, CHAIMBAULT PATRICK, SCHOHN HERVÉ. Evaluation of Δ2-pioglitazone, an analogue of pioglitazone, on colon cancer cell survival: Evidence of drug treatment association with autophagy and activation of the Nrf2/Keap1 pathway. Int J Oncol 2014; 45:426-38. [DOI: 10.3892/ijo.2014.2408] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 03/06/2014] [Indexed: 11/06/2022] Open
|
3
|
Salvo F, Bazin F, Kostrzewa A, Bandre C, Robinson P, Moore N, Bégaud B, Pariente A. Fibrates and Risk of Cancer in Tissues with High PPAR-α Concentration: A Nested Case–Control Study. Drug Saf 2014; 37:361-8. [DOI: 10.1007/s40264-014-0157-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
|
4
|
Penna F, Pin F, Costamagna D, Reffo P, Baccino FM, Bonelli G, Costelli P. Caspase 2 activation and ER stress drive rapid Jurkat cell apoptosis by clofibrate. PLoS One 2012; 7:e45327. [PMID: 23028936 PMCID: PMC3445471 DOI: 10.1371/journal.pone.0045327] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2010] [Accepted: 08/20/2012] [Indexed: 01/10/2023] Open
Abstract
Differently from the antiapoptotic action most commonly assigned to peroxisome proliferators (PPs), we demonstrated that some of them, clofibrate (CF) in particular, display clearcut apoptogenic properties on rat hepatoma cell lines. We and others could confirm that CF as well as various other PPs can induce apoptosis in a variety of cells, including human liver, breast and lung cancer cell lines. The present study was aimed at investigating the cytotoxic action of CF on a neoplastic line of different origin, the human T leukemia Jurkat cells. We observed that CF rapidly triggers an extensive and morphologically typical apoptotic process on Jurkat cells, though not in primary T cells, which is completely prevented by the polycaspase inhibitor zVADfmk. Gene silencing studies demonstrated that CF-induced apoptosis in Jurkat cells is partially dependent on activation of caspase 2. Looking for a possible trigger of caspase 2 activation, we observed increased levels of phosphorylated eIF2α and JNK in CF-treated cells. Moreover, intracellular Ca(2+) homeostasis was perturbed. Together, these findings are suggestive for the occurrence of ER stress, an event that is known to have the potential to activate caspase 2. The present observations demonstrate that CF induces in Jurkat cells a very fast and extensive apoptosis, that involves induction of ER stress and activation of caspases 2 and 3. Since apoptosis in Jurkat cells occurs at pharmacologically relevant concentrations of CF, the present findings encourage further in depth analysis in order to work out the potential implications of CF cytotoxcity on leukemic cells.
Collapse
Affiliation(s)
- Fabio Penna
- Department of Experimental Medicine and Oncology, University of Torino, Torino, Italy
| | | | | | | | | | | | | |
Collapse
|
5
|
Fujita M, Tohji C, Honda Y, Yamamoto Y, Nakamura T, Yagami T, Yamamori M, Okamura N. Cytotoxicity of 15-deoxy-Δ(12,14)-prostaglandin J(2) through PPARγ-independent pathway and the involvement of the JNK and Akt pathway in renal cell carcinoma. Int J Med Sci 2012; 9:555-66. [PMID: 22991494 PMCID: PMC3444976 DOI: 10.7150/ijms.4455] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Accepted: 08/31/2012] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION Agonists of peroxisome proliferator-activated receptor gamma (PPARγ) have been examined as chemopreventive and chemotherapeutic agents. The aim was to investigate the cytotoxicity and action mechanisms of 15-deoxy-Δ(12,14)-prostaglandin J(2) (15d-PGJ(2)), one of endogenous ligands for PPARγ, in terms of PPARγ-dependency and the mitogen-activated protein kinase (MAPK) and Akt pathway in three human renal cell carcinoma (RCC)-derived cell lines. METHODS 786-O, Caki-2 and ACHN cells were used as human RCC-derived cell lines. Cell viability and caspase-3 activity was detected by fluorescent reagents, and chromatin-condensation was observed with a brightfield fluorescent microscope after staining cells with Hoechst33342. The expression levels of proteins were detected by Western blot analysis. RESULTS 15d-PGJ(2) showed cytotoxicity in dose-dependent manner. 15d-PGJ(2) induced chromatin-condensation and elevated caspase-3 activity, and the cell viability was restored by co-treatment with a pan-caspase inhibitor, Z-VAD-FMK, indicating the involvement of caspase-dependent apoptosis. The cytotoxicity was not impaired by a PPARγ inhibitor, GW9662, suggesting that 15d-PGJ(2) exerted the cytotoxicity in a PPARγ-independent manner. Some antioxidants rescued cells from cell death induced by 15d-PGJ(2), but some did not, suggesting that reactive oxygen species (ROS) did not contribute to the apoptosis. 15d-PGJ(2) also increased the expression levels of phospho-c-Jun N terminal kinase (JNK) in Caki-2 cells, and decreased those of phospho-Akt in 786-O cells, indicating that the JNK MAPK and the Akt pathways participated in the anticancer effects of 15d-PGJ(2) in some cell lines. CONCLUSION 15d-PGJ(2) exerted cytotoxic effects accompanying caspase-dependent apoptosis, and this effect was elicited in a PPARγ-independent manner in three cell lines. In addition, the JNK MAPK and Akt pathway was involved in the cytotoxicity of 15d-PGJ(2) to some extent in some cell line. Therefore, our study showed the 15d-PGJ(2) to potentially be an interesting approach for RCC treatment.
Collapse
Affiliation(s)
- Megumi Fujita
- Department of Clinical Pharmacy, School of Pharmacy and Pharmaceutical Sciences, Mukogawa Women's University, 11-68 Koshien-kyuban-cho, Nishinomiya, Hyogo 663-8179, Japan
| | | | | | | | | | | | | | | |
Collapse
|
6
|
Silbajoris R, Osornio-Vargas AR, Simmons SO, Reed W, Bromberg PA, Dailey LA, Samet JM. Ambient particulate matter induces interleukin-8 expression through an alternative NF-κB (nuclear factor-kappa B) mechanism in human airway epithelial cells. ENVIRONMENTAL HEALTH PERSPECTIVES 2011; 119:1379-83. [PMID: 21665565 PMCID: PMC3230452 DOI: 10.1289/ehp.1103594] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Accepted: 06/10/2011] [Indexed: 05/03/2023]
Abstract
BACKGROUND Exposure to ambient air particulate matter (PM) has been shown to increase rates of cardiopulmonary morbidity and mortality, but the underlying mechanisms are still not well understood. OBJECTIVE We examined signaling events involved in the expression of the inflammatory gene interleukin-8 (IL-8) in human airway epithelial cells (HAECs) exposed to ambient PM collected in an urban area of Mexicali, Mexico. METHODS We studied IL-8 expression and regulatory signaling pathways in cultured HAECs exposed to Mexicali PM suspended in media for 0-4 hr. RESULTS Exposure resulted in a dose-dependent, 2- to 8-fold increase in IL-8 mRNA expression relative to controls. PM exposure induced IL-8 transcriptional activity in BEAS-2B cells that was dependent on the nuclear factor-kappa B (NF-κB) response element in the IL-8 promoter. Chromatin immunoprecipitation (ChIP) assays showed a 3-fold increase in binding of the p65 (RelA) NF-κB isoform to the IL-8 promoter sequence in HAECs exposed to PM. Western blot analyses showed elevated levels of phosphorylation of p65 but no changes in IκBα phosphorylation or degradation. IL-8 expression was blunted in a dose-dependent manner in BEAS-2B cells transduced with a lentivirus encoding a dominant negative p65 mutant in which phosphorylation sites were inactivated. CONCLUSION Taken together, these findings show that the increase in IL-8 mRNA expression in HAECs exposed to PM10 (PM ≤ 10 μm in aerodynamic diameter) is mediated through an NF-κB-dependent signaling mechanism that occurs through a pathway involving direct phosphorylation of the transcription factor p65 in the absence of IκBα degradation. These data show that exposure to PM10 in ambient air can induce inflammatory responses by activating specific signaling mechanisms in HAECs.
Collapse
Affiliation(s)
- Robert Silbajoris
- Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | | | | | | | | | | | | |
Collapse
|
7
|
PPARalpha ligands cause lymphocyte depletion and cell cycle block and this is associated with augmented TRB3 and reduced Cyclin B1 expression. Mol Immunol 2009; 46:3454-61. [PMID: 19748123 DOI: 10.1016/j.molimm.2009.08.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Revised: 07/18/2009] [Accepted: 08/05/2009] [Indexed: 12/14/2022]
Abstract
PPARalpha ligands are medications used clinically to prevent cardiovascular events, however studies have shown that these agents are also anti-inflammatory. Our previous studies have shown that PPARalpha ligands induce lymphocyte depletion. PPARalpha ligands also potently upregulate TRB3, a protein that has been associated with cell cycle arrest. Therefore the following studies were undertaken to determine the mechanisms associated with lymphocyte depletion. Our studies demonstrate that WY14,643, a PPARalpha ligand, decreases the amount of lymphocytes recovered after stimulation and reduces cellular divisions. Cells treated with WY14,643 also accumulate in the G2/S phase of the cell cycle. TRB3 has been shown to inhibit the phosphorylation of AKT/Protein Kinase B, and reduced activation of AKT has been associated with decreased cellular divisions and survival. However in lymphocytes, TRB3 did not reduce the phosphorylation of AKT, and WY14,643 treatment was associated with enhanced activation of AKT. Drosophila tribbles (TRB3 homolog) causes G2 arrest by decreasing the expression of a Cdc25c homolog. Lymphocytes stimulated and treated with WY14,643 have reduced expression of Cdc25c, however this is not associated with enhanced expression of phosphorylated-Cdc2 which induces G2 arrest. Instead we observed that WY14,643 consistently reduces the protein and mRNA expression of Cyclin B1. Moreover, TRB3 inhibits activation of a Cyclin B1 promoter construct. In summary, we propose that PPARalpha ligands may reduce cellular number by augmenting TRB3 expression, which in turn induces cell cycle arrest by reducing the expression of Cyclin B1. Reduced cellular divisions and cell cycle arrest may be responsible for some of the immunomodulatory effects of these agents that have been consistently observed in human trials.
Collapse
|
8
|
Ciglitazone induces apoptosis via activation of p38 MAPK and AIF nuclear translocation mediated by reactive oxygen species and Ca(2+) in opossum kidney cells. Toxicology 2008; 257:1-9. [PMID: 19110029 DOI: 10.1016/j.tox.2008.11.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2008] [Revised: 11/24/2008] [Accepted: 11/24/2008] [Indexed: 11/23/2022]
Abstract
We have previously demonstrated that the synthetic peroxisome proliferator-activated receptor-gamma (PPARgamma) agonist ciglitazone induces apoptosis accompanied by activation of p38 mitogen-activated protein kinase (MAPK) and nuclear translocation of apoptosis inducing factor (AIF) in opossum kidney (OK) renal epithelial cells. However, the precise mechanism by which ciglitazone induces activation of p38 MAPK and the role of AIF in the induction of the apoptosis are not defined. This study was therefore undertaken to determine whether the roles of reactive oxygen species (ROS) generation and intracellular Ca(2+) in the ciglitazone-induced activation of p38 MAPK and whether AIF nuclear translocation is responsible for the ciglitazone-induced apoptosis in OK renal epithelial cells. Ciglitazone caused generation of ROS and an increase in intracellular Ca(2+). Ciglitazone-induced cell death was reduced by the antioxidant Trolox, the Ca(2+) chelator EGTA, and the store-operated Ca(2+) channels (SOCC) blocker lanthanum chloride (La(3+)), indicating involvement of ROS and Ca(2+) in the ciglitazone-induced cell death. Ciglitazone-induced intracellular Ca(2+) increase was decreased by Trolox, while ROS generation was not affected by EGTA and La(3+), suggesting that ROS generation promote the increase of intracellular Ca(2+). Transfection of small interfering RNA (siRNA) of p38 MAPK or vector expressing microRNA (miRNA) of AIF prevented the ciglitazone-induced cell death. Activation of p38 MAPK, mitochondrial membrane depolarization, and AIF nuclear translocation induced by ciglitazone were inhibited by Trolox, EGTA and La(3+). Taken together, these results suggest that ROS-dependent intracellular Ca(2+) increase is responsible for activation of p38 MAPK and nuclear translocation of AIF by ciglitazone.
Collapse
|
9
|
Tirosh O, Ilan E, Anavi S, Ramadori G, Madar Z. Nutritional lipid-induced oxidative stress leads to mitochondrial dysfunction followed by necrotic death in FaO hepatocytes. Nutrition 2008; 25:200-8. [PMID: 18947977 DOI: 10.1016/j.nut.2008.07.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2008] [Revised: 07/03/2008] [Accepted: 07/18/2008] [Indexed: 10/21/2022]
Abstract
OBJECTIVE Mitochondrial dysfunction and hepatocyte cell death have been reported in fatty liver and non-alcoholic steatohepatitis. Our aim in this study was to evaluate whether direct exposure of hepatocytes to extracellular fat could facilitate such deleterious effects. METHODS FaO hepatic cells treated with fat was used as an in vitro model for steatosis. FaO hepatocytes were exposed to 0.1% triacylglycerols using commercially available lipid emulsion (LE) for various periods and studied for production of reactive oxygen species (ROS), mitochondrial function, and cell death parameters. To study the type of cell death, high-mobility group box chromosomal protein 1cellular levels, DNA fragmentation, and caspase activity were evaluated. RESULTS Cells incubated with LE for 6 h exhibited a marked increase in the production of intracellular ROS. Using treatments with peroxisome proliferator-activated receptor activators, mitochondrial electron-transfer chain inhibitor, and different sources of LE that did or did not contain medium-chain triacylglycerols, the mitochondria were found to be the source of ROS. LE treatment resulted in phosphorylation of adenosine monophosphate-activated protein kinase, accompanied by a decrease in adenosine triphosphate levels. Changes in intracellular ROS and energy levels were followed by cell death. FaO hepatocytes showed a significant reduction in high-mobility group box chromosomal protein-1 and little DNA fragmentation. Incubation with LE for 24 h did not change caspase-3 activity, indicating that hepatocyte death was necrotic. The antioxidant N-acetylcysteine was able to attenuate the changes in intracellular energy levels and ROS levels and to prevent cell death after exposure to LE. CONCLUSION These results suggest that exposure of FaO cells to LE leads to an increase in mitochondrial ROS production and a decrease in cellular energy levels followed by necrotic cell death.
Collapse
Affiliation(s)
- Oren Tirosh
- The Hebrew University of Jerusalem, Faculty of Agricultural, Food and Environmental Quality Sciences, Institute of Biochemistry, Food Science and Nutrition, Rehovot, Israel
| | | | | | | | | |
Collapse
|
10
|
Santos-Zago LF, Botelho AP, Oliveira ACD. Os efeitos do ácido linoléico conjugado no metabolismo animal: avanço das pesquisas e perspectivas para o futuro. REV NUTR 2008. [DOI: 10.1590/s1415-52732008000200008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Realizou-se uma revisão sistemática, sem restrição de data, sobre os efeitos fisiológicos do ácido linoléico conjugado sobre a regressão da carcinogênese, o estresse oxidativo, o metabolismo de lípides e glicose e a alteração da composição corporal. Objetivando estabelecer o aspecto histórico do avanço da pesquisa em ácido linoléico conjugado, consideraram-se artigos originais resultantes de trabalhos realizados com animais, com cultura de células e com humanos. Quanto às pesquisas sobre o efeito anticarcinogênico do ácido linoléico conjugado foram encontradas inúmeras evidências a esse respeito, especialmente na regressão dos tumores mamários e de cólon, induzida por ambos os isômeros os quais agem de maneiras distintas. Os pesquisadores se empenham em reinvestigar as propriedades antioxidantes do ácido linoléico conjugado. Embora tenham sido investigadas as propriedades antioxidantes, tem-se identificado efeito pró-oxidante, levando ao estresse oxidativo em humanos. Foram poucos os estudos que demonstraram efeito positivo significativo do ácido linoléico conjugado sobre o metabolismo dos lípides e da glicose e sobre a redução da gordura corporal, especialmente em humanos. Estudos sobre efeitos adversos foram também identificados. Há fortes indícios de que a ação deste ácido graxo conjugado sobre uma classe de fatores de transcrição - os receptores ativados por proliferadores de peroxissomo - e sobre a conseqüente modulação da expressão gênica, possa ser a explicação fundamental dos efeitos fisiológicos. Embora incipientes, os mais recentes estudos reforçam o conceito da nutrigenômica, ou seja, a modulação da expressão gênica induzida por compostos presentes na alimentação humana. O cenário atual estimula a comunidade científica a buscar um consenso sobre os efeitos do ácido linoléico conjugado em humanos, já que este está presente naturalmente em alguns alimentos, que, quando consumidos em quantidades adequadas e de forma freqüente, poderiam atuar como coadjuvantes na prevenção e no controle de inúmeras doenças crônicas.
Collapse
|
11
|
Kang DW, Choi CH, Park JY, Kang SK, Kim YK. Ciglitazone Induces Caspase-Independent Apoptosis through Down-Regulation of XIAP and Survivin in Human Glioma Cells. Neurochem Res 2007; 33:551-61. [DOI: 10.1007/s11064-007-9475-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Accepted: 08/15/2007] [Indexed: 12/20/2022]
|
12
|
Zhang X, Li L, Prabhakaran K, Zhang L, Leavesley H, Borowitz J, Isom G. Uncoupling protein-2 up-regulation and enhanced cyanide toxicity are mediated by PPARalpha activation and oxidative stress. Toxicol Appl Pharmacol 2007; 223:10-9. [PMID: 17573087 PMCID: PMC1994772 DOI: 10.1016/j.taap.2007.05.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2007] [Revised: 05/07/2007] [Accepted: 05/09/2007] [Indexed: 12/17/2022]
Abstract
Uncoupling protein 2 (UCP-2) is an inner mitochondrial membrane proton carrier that modulates mitochondrial membrane potential (DeltaPsi(m)) and uncouples oxidative phosphorylation. We have shown that up-regulation of UCP-2 by Wy14,643, a selective peroxisome proliferator-activated receptor-alpha (PPARalpha) agonist, enhances cyanide cytotoxicity. The pathway by which Wy14,643 up-regulates UCP-2 was determined in a dopaminergic cell line (N27 cells). Since dopaminergic mesencephalic cells are a primary brain target of cyanide, the N27 immortalized mesencephalic cell was used in this study. Wy14,643 produced a concentration- and time-dependent up-regulation of UCP-2 that was linked to enhanced cyanide-induced cell death. MK886 (PPARalpha antagonist) or PPARalpha knock-down by RNA interference (RNAi) inhibited PPARalpha activity as shown by the peroxisome proliferator response element-luciferase reporter assay, but only partially decreased up-regulation of UCP-2. The role of oxidative stress as an alternative pathway to UCP-2 up-regulation was determined. Wy14,643 induced a rapid surge of ROS generation and loading cells with glutathione ethyl ester (GSH-EE) or pre-treatment with vitamin E attenuated up-regulation of UCP-2. On the other hand, RNAi knockdown of PPARalpha did not alter ROS generation, suggesting a PPARalpha-independent component to the response. Co-treatment with PPARalpha-RNAi and GSH-EE blocked both the up-regulation of UCP-2 by Wy14,643 and the cyanide-induced cell death. It was concluded that a PPARalpha-mediated pathway and an oxidative stress pathway independent of PPARalpha mediate the up-regulation of UCP-2 and subsequent increased vulnerability to cyanide-induced cytotoxicity.
Collapse
Affiliation(s)
| | | | | | | | | | | | - G.E. Isom
- * Corresponding author. Fax: +1 765 404 1414. E-mail address: (G.E. Isom)
| |
Collapse
|
13
|
Soller M, Dröse S, Brandt U, Brüne B, von Knethen A. Mechanism of thiazolidinedione-dependent cell death in Jurkat T cells. Mol Pharmacol 2007; 71:1535-44. [PMID: 17325128 DOI: 10.1124/mol.107.034371] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Thiazolidinediones are synthetic agonists for the transcription factor peroxisome proliferator-activated receptor gamma (PPARgamma) and are therapeutically used as insulin sensitizers. Besides therapeutical benefits, potential side effects such as the induction of cell death by thiazolidinediones deserve consideration. Although PPARgamma-dependent and -independent cell death in response to thiazolidinediones has been described, we provide evidence supporting a new mechanism to account for thiazolidinedione-initiated but PPARgamma-independent cell demise. In Jurkat T cells, ciglitazone and troglitazone provoked rapid and dose-dependent cell death, whereas rosiglitazone did not alter cell viability. We found induction of apoptosis by troglitazone, whereas ciglitazone caused necrosis. Because preincubation with the reactive oxygen species (ROS) scavengers manganese (III) tetrakis(4-benzoic acid) porphyrin and vitamin C significantly inhibited ciglitazone- and partially troglitazone-mediated cell death, we suggest that ROS contribute to cytotoxicity. Assuming that ROS originate from mitochondria, studies in submitochondrial particles demonstrated that all thiazolidinediones inhibited complex I of the mitochondrial respiratory chain. However, only ciglitazone and troglitazone lowered complex II activity as well. Pharmacological inhibition of complexes I and II documented that complex II inhibition in Jurkat cells caused massive apoptotic cell death, whereas inhibition of complex I provoked only marginally apoptosis after 4-h treatment. Therefore, inhibition of complex II by ciglitazone and troglitazone is the main trigger of cell death. ATP depletion by ciglitazone, in contrast to troglitazone, is responsible for induction of necrosis. Our results demonstrate that despite their similar molecular structure, thiazolidinediones differently affect cell death, which might help to explain some adverse effects occurring during thiazolidinedione-based therapies.
Collapse
Affiliation(s)
- Mathias Soller
- Department of Biochemistry I-Pathobiochemistry, Johann Wolfgang Goethe University, Faculty of Medicine, Frankfurt, Main, Germany.
| | | | | | | | | |
Collapse
|
14
|
Grande SW, Andrade AJM, Talsness CE, Grote K, Golombiewski A, Sterner-Kock A, Chahoud I. A dose–response study following in utero and lactational exposure to di-(2-ethylhexyl) phthalate (DEHP): Reproductive effects on adult female offspring rats. Toxicology 2007; 229:114-22. [PMID: 17098345 DOI: 10.1016/j.tox.2006.10.005] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2006] [Revised: 10/10/2006] [Accepted: 10/10/2006] [Indexed: 11/18/2022]
Abstract
Di(2-ethylhexyl) phthalate (DEHP) is used in numerous consumer products, mainly imparting flexibility and durability to polyvinyl chloride (PVC) based plastics. It is a known reproductive and developmental toxicant in male rodents. However, data regarding effects of DEHP on female reproductive health are particularly sparse. We performed an extensive dose-response study following developmental exposure to DEHP and evaluated the effects on adult female reproductive function. Two wide ranges of doses, low and high, were tested. Female Wistar rats were treated daily with DEHP and peanut oil (vehicle control) by gavage from gestation day 6 to lactation day 21. The low doses were: 0.015, 0.045, 0.135, 0.405 and 1.215mgDEHP/kg/bw/day and the high doses were: 5, 15, 45, 135 and 405mg DEHP/kg/bw/day. At the doses tested, no effects on organ (liver, kidney, spleen, thymus, thyroid, ovary and uterus) or body weights were detected. Female offspring presented a normal pattern of estrous cyclicity with no hormonal alterations (serum estradiol and progesterone). A statistically significant increase in tertiary atretic follicles was observed at the highest dose (405mgDEHP/kg/day). Morphometric analysis indicated that uterus and vagina luminal epithelial cell height were unaffected by treatment. An increase in the number of ovarian atretic tertiary follicles was the only effect observed in adult female offspring exposed in utero and during lactation to DEHP.
Collapse
Affiliation(s)
- Simone W Grande
- Charité University Medical School Berlin, Campus Benjamin Franklin, Institute of Clinical Pharmacology and Toxicology, Department of Toxicology, Garystrasse 5, 14195 Berlin, Germany
| | | | | | | | | | | | | |
Collapse
|
15
|
Boelsterli UA, Lim PLK. Mitochondrial abnormalities--a link to idiosyncratic drug hepatotoxicity? Toxicol Appl Pharmacol 2006; 220:92-107. [PMID: 17275868 DOI: 10.1016/j.taap.2006.12.013] [Citation(s) in RCA: 166] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2006] [Revised: 12/12/2006] [Accepted: 12/12/2006] [Indexed: 12/17/2022]
Abstract
Idiosyncratic drug-induced liver injury (DILI) is a major clinical problem and poses a considerable challenge for drug development as an increasing number of successfully launched drugs or new potential drugs have been implicated in causing DILI in susceptible patient subsets. Although the incidence for a particular drug is very low (yet grossly underestimated), the outcome of DILI can be serious. Unfortunately, prediction has remained poor (both for patients at risk and for new chemical entities). The underlying mechanisms and the determinants of susceptibility have largely remained ill-defined. The aim of this review is to provide both clinical and experimental evidence for a major role of mitochondria both as a target of drugs causing idiosyncratic DILI and as mediators of delayed liver injury. We develop a unifying hypothesis that involves underlying genetic or acquired mitochondrial abnormalities as a major determinant of susceptibility for a number of drugs that target mitochondria and cause DILI. The mitochondrial hypothesis, implying gradually accumulating and initially silent mitochondrial injury in heteroplasmic cells which reaches a critical threshold and abruptly triggers liver injury, is consistent with the findings that typically idiosyncratic DILI is delayed (by weeks or months), that increasing age and female gender are risk factors and that these drugs are targeted to the liver and clearly exhibit a mitochondrial hazard in vitro and in vivo. New animal models (e.g., the Sod2(+/-) mouse) provide supporting evidence for this concept. However, genetic analyses of DILI patient samples are needed to ultimately provide the proof-of-concept.
Collapse
Affiliation(s)
- Urs A Boelsterli
- Molecular Toxicology Lab, Department of Pharmacology, Yong Loo Lin School of Medicine, Singapore.
| | | |
Collapse
|
16
|
Masubuchi Y, Kano S, Horie T. Mitochondrial permeability transition as a potential determinant of hepatotoxicity of antidiabetic thiazolidinediones. Toxicology 2006; 222:233-9. [PMID: 16621215 DOI: 10.1016/j.tox.2006.02.017] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2006] [Revised: 02/24/2006] [Accepted: 02/24/2006] [Indexed: 11/22/2022]
Abstract
Troglitazone, a thiazolidinedione class of antidiabetic agent, causes serious idiosyncratic hepatotoxicity. Troglitazone is metabolized to a reactive metabolite that covalently binds to cellular macromolecules, but the role of the covalent adduct in the hepatotoxicity is controversial. Because troglitazone has been found to cause cytotoxicity to hepatocytes along with mitochondrial dysfunction, we investigated the effects of troglitazone and other thiazolidinediones on mitochondrial function by using liver mitochondria fraction isolated from male CD-1 mice. Incubation of energized mitochondria with succinate in the presence of Ca2+ and troglitazone induced mitochondrial swelling, and the swelling was partially inhibited by cyclosporin A. Troglitazone also induced decreases in mitochondrial membrane potential and mitochondrial Ca2+ accumulation. These results demonstrate that troglitazone induces mitochondrial permeability transition (MPT). Similar results were obtained for ciglitazone, whereas rosiglitazone and pioglitazone, which are less hepatotoxic than troglitazone, had little effect on these mitochondria functions. It is therefore possible that the troglitazone-induced opening of MPT pore, which is not induced by rosiglitazone or pioglitazone, may contribute to the hepatotoxicity induced specifically by troglitazone.
Collapse
Affiliation(s)
- Yasuhiro Masubuchi
- Laboratory of Clinical Pharmacy, Faculty of Pharmaceutical Sciences, Chiba Institute of Science, 15-8 Shiomi-cho, Choshi, Chiba 288-0025, Japan
| | | | | |
Collapse
|
17
|
Wung BS, Wu CC, Hsu MC, Hsieh CW. 15-Deoxy-Δ12,14-prostaglandin J2 suppresses IL-6-induced STAT3 phosphorylation via electrophilic reactivity in endothelial cells. Life Sci 2006; 78:3035-42. [PMID: 16413037 DOI: 10.1016/j.lfs.2005.12.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2005] [Revised: 11/21/2005] [Accepted: 12/02/2005] [Indexed: 11/23/2022]
Abstract
In this study, the effects of 15d-PGJ(2) were investigated in IL-6-activated endothelial cells (ECs). 15d-PGJ(2) was found to abrogate phosphorylation on tyr705 of STAT3 in IL-6-treated ECs, in a dose- and time-dependent manner, but did not inhibit serine phosphorylation of STAT3 and the upperstream JAK2 phosphorylation. Other PPAR activators, such as WY1643 or ciglitazone, had no effect upon IL-6-induced STAT3 phosphorylation. Additionally, neither orthovanadate nor l-NAME treatment reverses the inhibition of STAT3 phosphorylation by 15d-PGJ(2). Otherwise, the effect of 15d-PGJ(2) requires the alpha,beta-unsaturated carbonyl group in the cyclopentane ring. A 15d-PGJ(2) analog, 9,10-Dihydro-15d-PGJ(2), which lack alpha,beta-unsaturated carbonyl group showed no increase in ROS production and no effect in inhibition of IL-6-induced STAT3 phosphorylation. The electrophilic compound, acrolein, mimics the inhibition effect of 15d-PGJ(2). Among the antioxidants, only NAC and glutathione reversed the effects of 15d-PGJ(2). NAC, glutathione and DTT all reversed the inhibition of STAT3 phosphorylation when preincubated with 15d-PGJ(2). The inhibition of ICAM-1 gene expression by 15d-PGJ(2) was abrogated by NAC and glutathione in IL-6-treated ECs. Taken together, these results suggest that 15d-PGJ(2) inhibits IL-6-stimulated phosphorylation on tyr705 of STAT3 dependent on its own electrophilic reactivity in ECs.
Collapse
Affiliation(s)
- B S Wung
- Department of Applied Microbiology, National Chiayi University, Chiayi, Taiwan.
| | | | | | | |
Collapse
|
18
|
Popp RL, Velasquez O, Bland J, Hughes P. Characterization of protein kinase C isoforms in primary cultured cerebellar granule cells. Brain Res 2006; 1083:70-84. [PMID: 16546140 DOI: 10.1016/j.brainres.2006.01.110] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2005] [Revised: 01/26/2006] [Accepted: 01/28/2006] [Indexed: 11/26/2022]
Abstract
Protein kinase C (PKC) is a family of serine/threonine kinases comprised of 10 isoforms. Although commercial antibodies are available for all 10 isoforms, the specificity of these antibodies has been questioned. We have identified immunoblot conditions in which commercially purchased PKC antibodies are specific for their respective isoform. We then used these conditions to determine that PKC isoforms alpha, betaI, betaII, delta, epsilon, gamma, lambda, theta, and zeta are present in rat primary cultured cerebellar granule cells (CGCs) 6-14 days in vitro (DIV). This PKC profile is identical to that observed in cerebellar homogenates taken from 6-, 14- and 21-day-old rats. Western blot analysis indicated that the classical and the atypical PKC isoforms were more prevalent in the cytosolic subcellular fraction compared to the particulate fraction under basal conditions. Immunoreactivity for the novel isoforms tended to be higher in the particulate fraction under basal conditions. Phorbol 12-myristate 13-acetate (PMA) treatment resulted in translocated immunoreactivity from the cytosolic to the particulate fraction for all of the classical and novel PKC isoforms, but not for the atypical isoforms. However, the degree of translocation as well as the speed of translocation varied among the isoforms. The stability of the individual isoforms after PMA-induced activation also varied among the isoforms. Differences in these parameters were dependent upon culture batches and PKC isoform groups. We have identified experimental conditions in which reproducible results can be obtained with primary cultured CGCs in the study of PKC. We discuss possible solutions for problems encountered when utilizing primary cultured neurons to study PKC-mediated signal transduction.
Collapse
Affiliation(s)
- R Lisa Popp
- Department of Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center, 3601 4th Street STOP 6592, Lubbock, TX 79430-0002, USA.
| | | | | | | |
Collapse
|
19
|
Avis I, Martínez A, Tauler J, Zudaire E, Mayburd A, Abu-Ghazaleh R, Ondrey F, Mulshine JL. Inhibitors of the Arachidonic Acid Pathway and Peroxisome Proliferator–Activated Receptor Ligands Have Superadditive Effects on Lung Cancer Growth Inhibition. Cancer Res 2005; 65:4181-90. [PMID: 15899809 DOI: 10.1158/0008-5472.can-04-3441] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Arachidonic acid (AA) metabolizing enzymes and peroxisome proliferator-activated receptors (PPARs) have been shown to regulate the growth of epithelial cells. We have previously reported that exposure to the 5-lipoxygenase activating protein-directed inhibitor MK886 but not the cyclooxygenase inhibitor, indomethacin, reduced growth, increased apoptosis, and up-regulated PPARalpha and gamma expression in breast cancer cell lines. In the present study, we explore approaches to maximizing the proapoptotic effects of PPARgamma on lung cancer cell lines. Non-small-cell cancer cell line A549 revealed dose-dependent PPARgamma reporter activity after treatment with MK886. The addition of indomethacin in combination with MK886 further increases reporter activity. We also show increased growth inhibition and up-regulation of apoptosis after exposure to MK886 alone, or in combination with indomethacin and the PPAR ligand, 15-deoxy-Delta12,14-prostaglandin J2 compared with single drug exposures on the adenocarcinoma cell line A549 and small-cell cancer cell lines H345, N417, and H510. Real-time PCR analyses showed increased PPAR mRNA and retinoid X receptor (RXR)alpha mRNA expression after exposure to MK886 and indomethacin in a time-dependent fashion. The results suggest that the principal proapoptotic effect of these drugs may be mediated through the known antiproliferative effects of the PPARgamma-RXR interaction. We therefore explored a three-drug approach to attempt to maximize this effect. The combination of low-dose MK886, ciglitazone, and 13-cis-retinoic acid interacted at least in a superadditive fashion to inhibit the growth of lung cancer cell lines A549 and H1299, suggesting that targeting PPARgamma and AA action is a promising approach to lung cancer growth with a favorable therapeutic index.
Collapse
Affiliation(s)
- Ingalill Avis
- Intervention Section, Cell and Cancer Biology Branch, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland 20892, USA
| | | | | | | | | | | | | | | |
Collapse
|
20
|
Kubota T, Yano T, Fujisaki K, Itoh Y, Oishi R. Fenofibrate induces apoptotic injury in cultured human hepatocytes by inhibiting phosphorylation of Akt. Apoptosis 2005; 10:349-58. [PMID: 15843896 DOI: 10.1007/s10495-005-0809-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Fibric acid derivatives have a potent and effective lipid-lowering action, however, the use of these compounds is sometimes limited due to the occurrence of hepatic injury. In the present study, we characterized cell injury induced by fenofibrate in cultured human hepatocytes. Fenofibrate caused a loss of cell viability and nuclear damage as assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling or by DNA electrophoresis, in which caspase activation is involved. The cell injury was accompanied by the shrinkage and the translocation of phosphatidyl serine from inner membrane to the outer membrane as determined by annexin V stain. The mRNA expression for bcl-2 was reduced by fenofibrate. An immunofluorescent stain with antiserum raised against phosphorylated Akt revealed that fenofibrate inhibited insulin-stimulated phosphorylation of Akt. Like fenofibrate, several compounds that inhibit the phosphorylation of Akt, including wortmannin, SH-6 and a high concentration (100 microM) of SB203580, reduced the viability of cultured human hepatocytes. Both nuclear damage and cell injury induced by fenofibrate were reversed by insulin in a concentration-dependent manner. In contrast, bezafibrate or 8(S)-hydroxyeicosatetraenoic acid had no hepatotoxic action. These findings suggest that fenofibrate causes caspase-dependent apoptosis in human hepatocytes by inhibiting phosphorylation of Akt, in which PPARalpha is not involved.
Collapse
Affiliation(s)
- T Kubota
- Department of Pharmacy, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
| | | | | | | | | |
Collapse
|