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Han J, Guo X, Tan W, Zhang F, Liu J, Wang W, Xu P, Lammi MJ. The expression of p-ATF2 involved in the chondeocytes apoptosis of an endemic osteoarthritis, Kashin-Beck disease. BMC Musculoskelet Disord 2013; 14:209. [PMID: 23866832 PMCID: PMC3726291 DOI: 10.1186/1471-2474-14-209] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 07/11/2013] [Indexed: 11/23/2022] Open
Abstract
Background The purpose of the study was to understand the function and expression of ATF2 by JNK and p38 signal pathways in the chondrocytes apoptosis of articular cartilage of the Kashin-Beck disease (KBD). Methods The changes of ATF2, JNK and p38 mRNAs and proteins were investigated between cartilage and chondrocyte as well as KBD and normal. JNK and p38 inhibitors were used as treatments to prevent apoptosis in chondrocytes from KBD patients. Results It was found that the protein levels of p-p38, p-JNK, ATF2 and p-ATF2 increased in KBD human cartilage which is in line with the higher mRNA levels of p38, JNK and ATF2 as compared both with normal cartilage and KBD chondrocytes. In addition, p-ATF2 was only detected in KBD cartilage. Furthermore, JNK inhibitor was more effective than p38 inhibitor in preventing chondrocyte apoptosis at equal concentrations of 10 μM. Conclusion These findings indicated the expression of p-ATF2 by JNK and p38 signal pathways involved in the chondrocyte apoptosis in cartilage with KBD.
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152
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Walluscheck D, Poehlmann A, Hartig R, Lendeckel U, Schönfeld P, Hotz-Wagenblatt A, Reissig K, Bajbouj K, Roessner A, Schneider-Stock R. ATF2 knockdown reinforces oxidative stress-induced apoptosis in TE7 cancer cells. J Cell Mol Med 2013; 17:976-88. [PMID: 23800081 PMCID: PMC3780530 DOI: 10.1111/jcmm.12071] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2012] [Accepted: 04/01/2013] [Indexed: 12/22/2022] Open
Abstract
Cancer cells showing low apoptotic effects following oxidative stress-induced DNA damage are mainly affected by growth arrest. Thus, recent studies focus on improving anti-cancer therapies by increasing apoptosis sensitivity. We aimed at identifying a universal molecule as potential target to enhance oxidative stress-based anti-cancer therapy through a switch from cell cycle arrest to apoptosis. A cDNA microarray was performed with hydrogen peroxide-treated oesophageal squamous epithelial cancer cells TE7. This cell line showed checkpoint activation via p21WAF1, but low apoptotic response following DNA damage. The potential target molecule was chosen depended on the following demands: it should regulate DNA damage response, cell cycle and apoptosis. As the transcription factor ATF2 is implicated in all these processes, we focused on this protein. We investigated checkpoint activation via ATF2. Indeed, ATF2 knockdown revealed ATF2-triggered p21WAF1 protein expression, suggesting p21WAF1 transactivation through ATF2. Using chromatin immunoprecipitation (ChIP), we identified a hitherto unknown ATF2-binding sequence in the p21WAF1 promoter. p-ATF2 was found to interact with p-c-Jun, creating the AP-1 complex. Moreover, ATF2 knockdown led to c-Jun downregulation. This suggests ATF2-driven induction of c-Jun expression, thereby enhancing ATF2 transcriptional activity via c-Jun-ATF2 heterodimerization. Notably, downregulation of ATF2 caused a switch from cell cycle arrest to reinforced apoptosis, presumably via p21WAF1 downregulation, confirming the importance of ATF2 in the establishment of cell cycle arrest. 1-Chloro-2,4-dinitrobenzene also led to ATF2-dependent G2/M arrest, suggesting that this is a general feature induced by oxidative stress. As ATF2 knockdown also increased apoptosis, we propose ATF2 as a target for combined oxidative stress-based anti-cancer therapies.
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Affiliation(s)
- Diana Walluscheck
- Department of Pathology, Otto-von-Guericke University, Magdeburg, Germany
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153
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Quintanilla RA, Godoy JA, Alfaro I, Cabezas D, von Bernhardi R, Bronfman M, Inestrosa NC. Thiazolidinediones promote axonal growth through the activation of the JNK pathway. PLoS One 2013; 8:e65140. [PMID: 23741474 PMCID: PMC3669289 DOI: 10.1371/journal.pone.0065140] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 04/22/2013] [Indexed: 11/18/2022] Open
Abstract
The axon is a neuronal process involved in protein transport, synaptic plasticity, and neural regeneration. It has been suggested that their structure and function are profoundly impaired in neurodegenerative diseases. Previous evidence suggest that Peroxisome Proliferator-Activated Receptors-γ (PPARγ promote neuronal differentiation on various neuronal cell types. In addition, we demonstrated that activation of PPARγby thiazolidinediones (TZDs) drugs that selectively activate PPARγ prevent neurite loss and axonal damage induced by amyloid-β (Aβ). However, the potential role of TZDs in axonal elongation and neuronal polarity has not been explored. We report here that the activation of PPARγ by TZDs promoted axon elongation in primary hippocampal neurons. Treatments with different TZDs significantly increased axonal growth and branching area, but no significant effects were observed in neurite elongation compared to untreated neurons. Treatment with PPARγ antagonist (GW 9662) prevented TZDs-induced axonal growth. Recently, it has been suggested that the c-Jun N-terminal kinase (JNK) plays an important role regulating axonal growth and neuronal polarity. Interestingly, in our studies, treatment with TZDs induced activation of the JNK pathway, and the pharmacological blockage of this pathway prevented axon elongation induced by TZDs. Altogether, these results indicate that activation of JNK induced by PPARγactivators stimulates axonal growth and accelerates neuronal polarity. These novel findings may contribute to the understanding of the effects of PPARγ on neuronal differentiation and validate the use of PPARγ activators as therapeutic agents in neurodegenerative diseases.
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Affiliation(s)
- Rodrigo A. Quintanilla
- Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- Laboratorio de Neurociencias, Departamento de Neurología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Juan A. Godoy
- Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Ivan Alfaro
- Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Deny Cabezas
- Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Rommy von Bernhardi
- Laboratorio de Neurociencias, Departamento de Neurología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Miguel Bronfman
- Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Nibaldo C. Inestrosa
- Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- * E-mail:
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154
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Greenblatt MB, Shim JH, Glimcher LH. Mitogen-activated protein kinase pathways in osteoblasts. Annu Rev Cell Dev Biol 2013; 29:63-79. [PMID: 23725048 DOI: 10.1146/annurev-cellbio-101512-122347] [Citation(s) in RCA: 182] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Mitogen-activated protein kinases (MAPKs) are ancient signal transducers well characterized as mediators of inflammation and neoplastic transformation. Recent work has expanded our understanding of their developmental functions, particularly in the regulation of bone mass via control of osteoblast differentiation. Here, we review the functions of MAPK pathways in osteoblasts, including a consideration of MAPK substrates. In particular, MAPKs function to regulate the key transcriptional mediators of osteoblast differentiation, with ERK and p38 MAPKs phosphorylating RUNX2, the master regulator of osteoblast differentiation. ERK also activates RSK2, which in turn phosphorylates ATF4, a transcriptional regulator of late-stage osteoblast synthetic functions. The MAP3Ks and MAP2Ks upstream of MAPKs have also been investigated, and significant differences have been found in the wiring of MAPK pathways in osteoblasts relative to other tissues. Thus, the investigation of MAPKs in osteoblasts has both revealed critical mechanisms for the maintenance of bone mass and added to our understanding of how the individual components of MAPK pathways function in concert in a complex in vivo system.
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Affiliation(s)
- Matthew B Greenblatt
- Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts 02115;
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155
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Parra E, Gutiérrez L, Ferreira J. Increased expression of p21Waf1/Cip1 and JNK with costimulation of prostate cancer cell activation by an siRNA Egr-1 inhibitor. Oncol Rep 2013; 30:911-6. [PMID: 23715767 DOI: 10.3892/or.2013.2503] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Accepted: 03/03/2013] [Indexed: 11/06/2022] Open
Abstract
The p21Waf1/Cip1 protein (hereafter, p21) and the c‑Jun N-terminal kinase (JNK) are two well-characterized cell modulators that play a crucial role in cell differentiation, senescence and apoptosis. Here, we report that transcription of the p21Waf1/Cip1 and JNK-1 genes is affected by inhibition of the early growth response-1 (Egr-1) in response to a small interfering RNA [siRNA)-Egr-1] in LNCaP and PC-3 prostate carcinoma cell lines. The expression levels of protein were determined by western blotting, and apoptosis was measured by propidium iodide staining and flow cytometric analysis. Inhibition of Egr-1, p21 and JNK-1 was carried out by siRNAs. LNCaP and PC-3 cells exhibited readily detectable Egr-1, JNK and p21, even in low serum medium without the addition of other exogenous agents. The expression of Egr-1, p21 and JNK was strongly increased after treatment of the cells with TPA, tumor necrosis factor-α (TNF-α) or arsenite. Suppression of Egr-1 expression by siRNA abrogated the ability of TPA to induce Egr-1 and JNK-1 activities, moderately increasing the p21 activity and abrogating the anti-apoptotic effect of Egr-1 observed in the prostate cancer cell lines. Moreover, blockade of p21 and JNK was unable to decrease the activity of Egr-1, while siRNA against p21 abrogated the pro‑apoptotic effect of p21. The results demonstrated that Egr-1 acts as a key player in prostate tumor cell growth and survival, while p21 plays a key pro‑apoptotic role in LNCaP and PC-3 prostate carcinoma cell lines.
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Affiliation(s)
- Eduardo Parra
- Laboratory of Experimental Biomedicine, University of Tarapaca, Campus Esmeralda, Iquique, Chile.
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156
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Al-Sadi R, Guo S, Ye D, Dokladny K, Alhmoud T, Ereifej L, Said HM, Ma TY. Mechanism of IL-1β modulation of intestinal epithelial barrier involves p38 kinase and activating transcription factor-2 activation. THE JOURNAL OF IMMUNOLOGY 2013; 190:6596-606. [PMID: 23656735 DOI: 10.4049/jimmunol.1201876] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The defective intestinal epithelial tight junction (TJ) barrier has been postulated to be an important pathogenic factor contributing to intestinal inflammation. It has been shown that the proinflammatory cytokine IL-1β causes an increase in intestinal permeability; however, the signaling pathways and the molecular mechanisms involved remain unclear. The major purpose of this study was to investigate the role of the p38 kinase pathway and the molecular processes involved. In these studies, the in vitro intestinal epithelial model system (Caco-2 monolayers) was used to delineate the cellular and molecular mechanisms, and a complementary in vivo mouse model system (intestinal perfusion) was used to assess the in vivo relevance of the in vitro findings. Our data indicated that the IL-1β increase in Caco-2 TJ permeability correlated with an activation of p38 kinase. The activation of p38 kinase caused phosphorylation and activation of p38 kinase substrate, activating transcription factor (ATF)-2. The activated ATF-2 translocated to the nucleus where it attached to its binding motif on the myosin L chain kinase (MLCK) promoter region, leading to the activation of MLCK promoter activity and gene transcription. Small interfering RNA induced silencing of ATF-2, or mutation of the ATF-2 binding motif prevented the activation of MLCK promoter and MLCK mRNA transcription. Additionally, in vivo intestinal perfusion studies also indicated that the IL-1β increase in mouse intestinal permeability required p38 kinase-dependent activation of ATF-2. In conclusion, these studies show that the IL-1β-induced increase in intestinal TJ permeability in vitro and in vivo was regulated by p38 kinase activation of ATF-2 and by ATF-2 regulation of MLCK gene activity.
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Affiliation(s)
- Rana Al-Sadi
- Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA
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157
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Oxidative stress and MAPK involved into ATF2 expression in immortalized human urothelial cells treated by arsenic. Arch Toxicol 2013; 87:981-9. [PMID: 23591579 DOI: 10.1007/s00204-013-1058-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Accepted: 04/03/2013] [Indexed: 10/26/2022]
Abstract
ATF2 is a subfamily member of AP-1 and has an important role in cellular stress responses. ATF2 has been implicated in a transcriptional response leading to cell migration and malignant tumor progression. However, little is known about the effect of arsenic on expression of ATF2 and regulatory pathways in human urothelial cells. In this study, ATF2 expression was measured in NaAsO(2)-treated human uroepithelial cell line (SV-HUC-1) with 1, 2, 4, 8 and 10 μM concentrations in order to provide some basis data for the study on mechanism of bladder cancer induced by arsenic. We found that ATF2 expression levels at 2, 4, 8 and 10 μM arsenic-treated cells were significantly higher than those of control cells, and the strongest expression occurred in 4 μM NaAsO(2)-treated cells. Antioxidants (melatonin) and JNK or p38 inhibitors decreased significantly arsenic-induced ATF2 expression. Taken together, these data indicated that the increasing of ATF2 expression is mediated via oxidative stress induced by arsenic in SV-HUC-1 cells, and JNK or p38 rather than ERK is responsible for arsenic-induced ATF2 expression. ROS were also involved in arsenic induced the activation of JNK and p38 MAPK signaling pathway.
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158
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Lee JK, Ko SH, Ye SK, Chung MH. 8-Oxo-2′-deoxyguanosine ameliorates UVB-induced skin damage in hairless mice by scavenging reactive oxygen species and inhibiting MMP expression. J Dermatol Sci 2013; 70:49-57. [DOI: 10.1016/j.jdermsci.2013.01.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 01/21/2013] [Accepted: 01/28/2013] [Indexed: 01/21/2023]
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159
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Yu Y, Li J, Wan Y, Lu J, Gao J, Huang C. GADD45α induction by nickel negatively regulates JNKs/p38 activation via promoting PP2Cα expression. PLoS One 2013; 8:e57185. [PMID: 23536762 PMCID: PMC3594291 DOI: 10.1371/journal.pone.0057185] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Accepted: 01/15/2013] [Indexed: 12/20/2022] Open
Abstract
Growth arrest and DNA damage (GADD) 45α is a member of GADD inducible gene family, and is inducible in cell response to oxidative stress. GADD45α upregulation induces MKK4/JNK activation in some published experimental systems. However, we found here that the depletion of GADD45α (GADD45α−/−) in mouse embryonic fibroblasts (MEFs) resulted in an increase in the phosphorylation of MKK4/7, MKK3/6 and consequently specific up-regulated the activation of JNK/p38 and their downstream transcription factors, such as c-Jun and ATF2, in comparison to those in GADD45α+/+ MEFs cell following nickel exposure. This up-regulation of MKK-JNK/p38 pathway in GADD45α−/− cell could be rescued by the reconstitutional expression of HA-GADD45α in GADD45α−/− MEFs, GADD45α−/−(HA-GADD45α). Subsequent studies indicated that GADD45α deletion repressed expression of PP2Cα, the phosphotase of MKK3/6 and MKK4/7, whereas ectopic expression of HA-PP2Cα in GADD45α−/− cells attenuated activation of MKK3/6-p38 and MKK4/7-JNK pathways. Collectively, our results demonstrate a novel function and mechanism responsible for GADD45α regulation of MKK/MAPK pathway, further provides insight into understanding the big picture of GADD45α in the regulation of cellular responses to oxidative stress and environmental carcinogens.
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Affiliation(s)
- Yonghui Yu
- Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, New York, United States of America
- Oversea Laboratory, Center for Medical Research, Wuhan University, Wuhan, Hubei, China
| | - Jingxia Li
- Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, New York, United States of America
| | - Yu Wan
- Oversea Laboratory, Center for Medical Research, Wuhan University, Wuhan, Hubei, China
| | - Jianyi Lu
- Zhejiang Provincial Key Laboratory for Technology & Application of Model Organisms, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Jimin Gao
- Zhejiang Provincial Key Laboratory for Technology & Application of Model Organisms, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
- * E-mail: (JG); (CH)
| | - Chuanshu Huang
- Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, New York, United States of America
- * E-mail: (JG); (CH)
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160
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JNK-interacting protein 3 mediates the retrograde transport of activated c-Jun N-terminal kinase and lysosomes. PLoS Genet 2013; 9:e1003303. [PMID: 23468645 PMCID: PMC3585007 DOI: 10.1371/journal.pgen.1003303] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 12/19/2012] [Indexed: 12/24/2022] Open
Abstract
Retrograde axonal transport requires an intricate interaction between the dynein motor and its cargo. What mediates this interaction is largely unknown. Using forward genetics and a novel in vivo imaging approach, we identified JNK-interacting protein 3 (Jip3) as a direct mediator of dynein-based retrograde transport of activated (phosphorylated) c-Jun N-terminal Kinase (JNK) and lysosomes. Zebrafish jip3 mutants (jip3nl7) displayed large axon terminal swellings that contained high levels of activated JNK and lysosomes, but not other retrograde cargos such as late endosomes and autophagosomes. Using in vivo analysis of axonal transport, we demonstrated that the terminal accumulations of activated JNK and lysosomes were due to a decreased frequency of retrograde movement of these cargos in jip3nl7, whereas anterograde transport was largely unaffected. Through rescue experiments with Jip3 engineered to lack the JNK binding domain and exogenous expression of constitutively active JNK, we further showed that loss of Jip3–JNK interaction underlies deficits in pJNK retrograde transport, which subsequently caused axon terminal swellings but not lysosome accumulation. Lysosome accumulation, rather, resulted from loss of lysosome association with dynein light intermediate chain (dynein accessory protein) in jip3nl7, as demonstrated by our co-transport analyses. Thus, our results demonstrate that Jip3 is necessary for the retrograde transport of two distinct cargos, active JNK and lysosomes. Furthermore, our data provide strong evidence that Jip3 in fact serves as an adapter protein linking these cargos to dynein. To form and maintain connections, neurons require the active transport of proteins and organelles between the neuronal cell body and axon terminals. Inhibition of this “axonal” transport has been linked to neurodegenerative diseases. Despite the importance of this process, to date there was no vertebrate model system where axonal transport could be studied in an intact animal. Our study introduces zebrafish as such a model and demonstrates its power for the analysis of axonal transport. We used this system to 1) initiate a genetic screen to find novel mediators of axonal transport; 2) develop in vivo imaging strategies to visualize axonal transport in real time in the intact animal; and 3) discover, using these methods, that JNK interacting protein 3 (Jip3) is required for the transport of two cargos, a kinase and lysosomes, from axon terminals to the cell body (retrograde transport). In the absence of Jip3, these cargos accumulate and axon terminals become dysmorphic, though the retrograde transport of other cargos is normal. Interestingly, abnormal localization of these cargos has been linked to axonal disease states, but our work is the first to identify a specific adapter protein necessary for their transport from axon terminals.
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161
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Walczynski J, Lyons S, Jones N, Breitwieser W. Sensitisation of c-MYC-induced B-lymphoma cells to apoptosis by ATF2. Oncogene 2013; 33:1027-36. [DOI: 10.1038/onc.2013.28] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 12/08/2012] [Accepted: 12/30/2012] [Indexed: 12/17/2022]
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162
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Desch M, Hackmayer G, Todorov VT. Identification of ATF2 as a transcriptional regulator of renin gene. Biol Chem 2013; 393:93-100. [PMID: 22628303 DOI: 10.1515/bc-2011-157] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2011] [Accepted: 10/07/2011] [Indexed: 11/15/2022]
Abstract
The cAMP response element (enhCRE) in the distal enhancer regulatory region of renin gene is believed to play a major role in the control of renin transcription. enhCRE binds the CRE-binding protein (CREB), which is the main transcription factor target of cAMP signaling. Using the mouse renin-producing cell line As4.1 we found that activating transcription factor-2 (ATF2) also binds to enhCRE. N-terminal phosphorylation of ATF2, which controls its transactivation, is associated with downregulation of renin gene expression by the cytokine tumor necrosis factor-α (TNFα). The ubiquitin proteasome inhibitor MG132 also phosphorylates ATF2 and inhibits renin expression. Knockdown of ATF2 attenuated the suppression of renin gene expression by MG132, thus demonstrating that ATF2 mediates the inhibitory effect of MG132. In addition, MG132 increased the DNA-binding of ATF2 as well as the ratio of bound ATF2 to CREB. Using ATF2- and CREB-Gal4 fusion protein constructs coupled with luciferase reporter system we showed that ATF2 has a weaker transactivating capacity than CREB. These data suggest that ATF2 represses renin expression by drifting the transcriptional control of renin gene away from CREB. Accordingly, TNFα completely abrogated the cAMP-dependent stimulation of renin gene expression.
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Affiliation(s)
- Michael Desch
- Institute of Physiology, University of Regensburg, D93040 Regensburg, Germany
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163
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Noonan EM, Shah D, Yaffe MB, Lauffenburger DA, Samson LD. O6-Methylguanine DNA lesions induce an intra-S-phase arrest from which cells exit into apoptosis governed by early and late multi-pathway signaling network activation. Integr Biol (Camb) 2013; 4:1237-55. [PMID: 22892544 DOI: 10.1039/c2ib20091k] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The O(6)-methylguanine (O(6)MeG) DNA lesion is well known for its mutagenic, carcinogenic, and cytotoxic properties, and understanding how a cell processes such damage is of critical importance for improving current cancer therapy. Here we use human cells differing only in their O(6)MeG DNA methyltransferase (MGMT) or mismatch repair (MMR) status to explore the O(6)MeG/MMR-dependent molecular and cellular responses to treatment with the methylating agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). We find that O(6)MeG triggers MMR-dependent cell cycle perturbations in both the first and second cell cycle post treatment. At lower levels of damage, we show that a transient arrest in the second S-phase precedes survival and progression into subsequent cell cycles. However, at higher levels of damage, arrest in the second S-phase coincides with a cessation of DNA replication followed by initiation of apoptotic cell death. Further, we show that entry into apoptotic cell death is specifically from S-phase of the second cell cycle. Finally, we demonstrate the key role of an O(6)MeG/MMR-dependent multi-pathway, multi-time-scale signaling network activation, led by early ATM, H2AX, CHK1, and p53 phosphorylation and followed by greatly amplified late phosphorylation of the early pathway nodes along with activation of the CHK2 kinase and the stress-activated JNK kinase.
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Affiliation(s)
- Ericka M Noonan
- Biological Engineering Department, Biology Department, Center for Environmental Health Sciences, Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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164
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Glatz G, Gógl G, Alexa A, Reményi A. Structural mechanism for the specific assembly and activation of the extracellular signal regulated kinase 5 (ERK5) module. J Biol Chem 2013; 288:8596-8609. [PMID: 23382384 PMCID: PMC3605678 DOI: 10.1074/jbc.m113.452235] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Mitogen-activated protein kinase (MAPK) activation depends on a linear binding motif found in all MAPK kinases (MKK). In addition, the PB1 (Phox and Bem1) domain of MKK5 is required for extracellular signal regulated kinase 5 (ERK5) activation. We present the crystal structure of ERK5 in complex with an MKK5 construct comprised of the PB1 domain and the linear binding motif. We show that ERK5 has distinct protein-protein interaction surfaces compared with ERK2, which is the closest ERK5 paralog. The two MAPKs have characteristically different physiological functions and their distinct protein-protein interaction surface topography enables them to bind different sets of activators and substrates. Structural and biochemical characterization revealed that the MKK5 PB1 domain cooperates with the MAPK binding linear motif to achieve substrate specific binding, and it also enables co-recruitment of the upstream activating enzyme and the downstream substrate into one signaling competent complex. Studies on present day MAPKs and MKKs hint on the way protein kinase networks may evolve. In particular, they suggest how paralogous enzymes with similar catalytic properties could acquire novel signaling roles by merely changing the way they make physical links to other proteins.
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Affiliation(s)
- Gábor Glatz
- Department of Biochemistry, Eötvös Loránd University, Budapest H-1117, Hungary
| | - Gergő Gógl
- Department of Biochemistry, Eötvös Loránd University, Budapest H-1117, Hungary
| | - Anita Alexa
- Department of Biochemistry, Eötvös Loránd University, Budapest H-1117, Hungary
| | - Attila Reményi
- Department of Biochemistry, Eötvös Loránd University, Budapest H-1117, Hungary.
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165
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Rokumi-jio-gan-Containing Prescriptions Attenuate Oxidative Stress, Inflammation, and Apoptosis in the Remnant Kidney. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2012; 2012:587902. [PMID: 23243456 PMCID: PMC3518768 DOI: 10.1155/2012/587902] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Revised: 10/09/2012] [Accepted: 10/12/2012] [Indexed: 02/07/2023]
Abstract
Two Rokumi-jio-gan-containing prescriptions (Hachimi-jio-gan and Bakumi-jio-gan) were selected to examine their actions in nephrectomized rats. Each prescription was given orally to rats for 10 weeks after the excision of five-sixths of their kidney volumes, and its effect was compared with non-nephrectomized and normal rats. Rats given Hachimi-jio-gan and Bakumi-jio-gan showed an improvement of renal functional parameters such as serum urea nitrogen, creatinine, creatinine clearance, and urinary protein. The nephrectomized rats exhibited the up-regulation of nicotinamide adenine dinucleotide phosphate oxidase subunits, c-Jun N-terminal kinase (JNK), phosphor-JNK, c-Jun, transforming growth factor-β1, nuclear factor-kappa B, cyclooxygenase-2, inducible nitric oxide synthase, monocyte chemotactic protein-1, intracellular adhesion molecule-1, Bax, cytochrome c, and caspase-3, and down-regulation of NF-E2-related factor 2, heme oxygenase-1, and survivin; however, Bakumi-jio-gan administration acts as a regulator in inflammatory reactions caused by oxidative stress in renal failure. Moreover, the JNK pathway and apoptosis-related protein expressions, Bax, caspase-3, and survivin, were ameliorated to the normal levels by Hachimi-jio-gan administration. The development of renal lesions, glomerular sclerosis, tubulointerstitial damage, and arteriolar sclerotic lesions, estimated by histopathological evaluation and scoring, was strong in the groups administered Hachimi-jio-gan rather than Bakumi-jio-gan. This study suggests that Rokumi-jio-gan-containing prescriptions play a protective role in the progression of renal failure.
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Garai Á, Zeke A, Gógl G, Törő I, Fördős F, Blankenburg H, Bárkai T, Varga J, Alexa A, Emig D, Albrecht M, Reményi A. Specificity of linear motifs that bind to a common mitogen-activated protein kinase docking groove. Sci Signal 2012; 5:ra74. [PMID: 23047924 DOI: 10.1126/scisignal.2003004] [Citation(s) in RCA: 122] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Mitogen-activated protein kinases (MAPKs) have a docking groove that interacts with linear "docking" motifs in binding partners. To determine the structural basis of binding specificity between MAPKs and docking motifs, we quantitatively analyzed the ability of 15 docking motifs from diverse MAPK partners to bind to c-Jun amino-terminal kinase 1 (JNK1), p38α, and extracellular signal-regulated kinase 2 (ERK2). Classical docking motifs mediated highly specific binding only to JNK1, and only those motifs with a sequence pattern distinct from the classical MAPK binding docking motif consensus differentiated between the topographically similar docking grooves of ERK and p38α. Crystal structures of four complexes of MAPKs with docking peptides, representing JNK-specific, ERK-specific, or ERK- and p38-selective binding modes, revealed that the regions located between consensus positions in the docking motifs showed conformational diversity. Although the consensus positions in the docking motifs served as anchor points that bound to common MAPK surface features and mostly contributed to docking in a nondiscriminatory fashion, the conformation of the intervening region between the anchor points mostly determined specificity. We designed peptides with tailored MAPK binding profiles by rationally changing the length and amino acid composition of intervening regions located between anchor points. These results suggest a coherent structural model for MAPK docking specificity that reveals how short linear motifs binding to a common kinase docking groove can mediate diverse interaction patterns and contribute to correct MAPK partner selection in signaling networks.
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Affiliation(s)
- Ágnes Garai
- Department of Biochemistry, Eötvös Loránd University, Pázmány Péter sétány 1/C, 1117 Budapest, Hungary
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167
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Mashima T, Seimiya H, Chen Z, Kataoka S, Tsuruo T. Apoptosis resistance in tumor cells. Cytotechnology 2012; 27:293-308. [PMID: 19002800 DOI: 10.1023/a:1008058031511] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Various antitumor agents induce apoptotic cell death in tumor cells. Since the apoptosis program in tumor cells plays a critical role in the chemotherapy-induced tumor cell killing, it is suggested that the defect in the signaling pathway of apoptosis could cause a new form of multidrug resistance in tumor cells. This article describes the recent findings concerning the mechanisms of chemotherapy-induced apoptosis and discusses the implication of apoptosis resistance in cancer chemotherapy.
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Affiliation(s)
- T Mashima
- Institute of Molecular and Cellular Biosciences, University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113, Japan
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168
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Temme N, Oeser B, Massaroli M, Heller J, Simon A, Collado IG, Viaud M, Tudzynski P. BcAtf1, a global regulator, controls various differentiation processes and phytotoxin production in Botrytis cinerea. MOLECULAR PLANT PATHOLOGY 2012; 13:704-18. [PMID: 22293085 PMCID: PMC6638710 DOI: 10.1111/j.1364-3703.2011.00778.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Atf1-homologous basic region leucine zipper (bZIP) transcription factors are known to act downstream of the stress-activated mitogen-activated protein kinase (SAPK) cascade in mammals, as well as in several fungi; they regulate the transcription of genes involved in the general stress response. Functional analyses of BcAtf1 in Botrytis cinerea show that it is also connected to the SAPK BcSak1, as it shares several stress response target genes. However, Δbcatf1 mutants are not hypersensitive to osmotic or oxidative stress, as are Δbcsak1 mutants. Both BcSak1 and BcAtf1 are regulators of differentiation, but their roles in these processes are almost inverse as, in contrast with Δbcsak1, Δbcatf1 mutants are significantly impaired in conidia production and do not differentiate any sclerotia. They show extremely vigorous growth in axenic culture, with a thick layer of aerial hyphae and a marked increase in colonization efficiency on different host plants and tissues. In addition, the sensitivity to cell wall-interfering agents is increased strongly. Microarray analyses demonstrate that the loss of BcAtf1 leads to extensive transcriptional changes: apart from stress response genes, the expression of a broad set of genes, probably involved in primary metabolism, cell wall synthesis and development, is affected by BcAtf1. Unexpectedly, BcAtf1 also controls secondary metabolism: the mutant contains significantly elevated levels of phytotoxins. These data indicate that BcAtf1 controls a diversity of cellular processes and has broad regulatory functions.
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Affiliation(s)
- Nora Temme
- Institut für Biologie und Biotechnologie der Pflanzen, Westf. Wilhelms-Universität, Hindenburgplatz 55, D-48143 Münster, Germany
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169
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Feidantsis K, Anestis A, Vasara E, Kyriakopoulou-Sklavounou P, Michaelidis B. Seasonal variations of cellular stress response in the heart and gastrocnemius muscle of the water frog (Pelophylax ridibundus). Comp Biochem Physiol A Mol Integr Physiol 2012; 162:331-9. [DOI: 10.1016/j.cbpa.2012.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 04/03/2012] [Accepted: 04/03/2012] [Indexed: 10/28/2022]
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170
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Kyriakis JM, Avruch J. Mammalian MAPK signal transduction pathways activated by stress and inflammation: a 10-year update. Physiol Rev 2012; 92:689-737. [PMID: 22535895 DOI: 10.1152/physrev.00028.2011] [Citation(s) in RCA: 1001] [Impact Index Per Article: 83.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The mammalian stress-activated families of mitogen-activated protein kinases (MAPKs) were first elucidated in 1994, and by 2001, substantial progress had been made in identifying the architecture of the pathways upstream of these kinases as well as in cataloguing candidate substrates. This information remains largely sound. Nevertheless, an informed understanding of the physiological and pathophysiological roles of these kinases remained to be accomplished. In the past decade, there has been an explosion of new work using RNAi in cells, as well as transgenic, knockout and conditional knockout technology in mice that has provided valuable insight into the functions of stress-activated MAPK pathways. These findings have important implications in our understanding of organ development, innate and acquired immunity, and diseases such as atherosclerosis, tumorigenesis, and type 2 diabetes. These new developments bring us within striking distance of the development and validation of novel treatment strategies. Herein we first summarize the molecular components of the mammalian stress-regulated MAPK pathways and their regulation as described thus far. We then review some of the in vivo functions of these pathways.
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Affiliation(s)
- John M Kyriakis
- Molecular Cardiology Research Institute, Tufts Medical Center, 800 Washington St., Box 8486, Boston, MA 02111, USA.
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171
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172
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Lau E, Ronai ZA. ATF2 - at the crossroad of nuclear and cytosolic functions. J Cell Sci 2012; 125:2815-24. [PMID: 22685333 DOI: 10.1242/jcs.095000] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
An increasing number of transcription factors have been shown to elicit oncogenic and tumor suppressor activities, depending on the tissue and cell context. Activating transcription factor 2 (ATF2; also known as cAMP-dependent transcription factor ATF-2) has oncogenic activities in melanoma and tumor suppressor activities in non-malignant skin tumors and breast cancer. Recent work has shown that the opposing functions of ATF2 are associated with its subcellular localization. In the nucleus, ATF2 contributes to global transcription and the DNA damage response, in addition to specific transcriptional activities that are related to cell development, proliferation and death. ATF2 can also translocate to the cytosol, primarily following exposure to severe genotoxic stress, where it impairs mitochondrial membrane potential and promotes mitochondrial-based cell death. Notably, phosphorylation of ATF2 by the epsilon isoform of protein kinase C (PKCε) is the master switch that controls its subcellular localization and function. Here, we summarize our current understanding of the regulation and function of ATF2 in both subcellular compartments. This mechanism of control of a non-genetically modified transcription factor represents a novel paradigm for 'oncogene addiction'.
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Affiliation(s)
- Eric Lau
- Signal Transduction Program, Sanford-Burnham Medical Research Institute, 10901 N. Torrey Pines Rd, La Jolla, CA 92130, USA.
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173
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Abstract
MAPK (mitogen-activated protein kinase) pathways are among the most frequently deregulated signalling events in cancer. Among the critical targets of MAPK activities are members of the AP-1 (activator protein 1) transcription factor, a dimeric complex consisting of Jun, Fos, Maf and ATF (activating transcription factor) family DNA-binding proteins. Depending on the cellular context, the composition of the dimeric complexes determines the regulation of growth, survival or apoptosis. JNK (c-Jun N-terminal kinase), p38 and a number of Jun and Fos family proteins have been analysed for their involvement in oncogenic transformation and tumour formation. These data are also emerging for the ATF components of the AP-1 factor. The aim of the present review is to provide an overview of the functions of two ATF family proteins, ATF2 and ATF7, in mammalian development and their potential functions in tumour formation.
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174
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Švajger U, Jeras M. Anti-inflammatory Effects of Resveratrol and Its Potential Use in Therapy of Immune-mediated Diseases. Int Rev Immunol 2012; 31:202-22. [DOI: 10.3109/08830185.2012.665108] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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175
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MEKK1-MKK4-JNK-AP1 pathway negatively regulates Rgs4 expression in colonic smooth muscle cells. PLoS One 2012; 7:e35646. [PMID: 22545125 PMCID: PMC3335800 DOI: 10.1371/journal.pone.0035646] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Accepted: 03/19/2012] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Regulator of G-protein Signaling 4 (RGS4) plays an important role in regulating smooth muscle contraction, cardiac development, neural plasticity and psychiatric disorder. However, the underlying regulatory mechanisms remain elusive. Our recent studies have shown that upregulation of Rgs4 by interleukin (IL)-1β is mediated by the activation of NFκB signaling and modulated by extracellular signal-regulated kinases, p38 mitogen-activated protein kinase, and phosphoinositide-3 kinase. Here we investigate the effect of the c-Jun N-terminal kinase (JNK) pathway on Rgs4 expression in rabbit colonic smooth muscle cells. METHODOLOGY/PRINCIPAL FINDINGS Cultured cells at first passage were treated with or without IL-1β (10 ng/ml) in the presence or absence of the selective JNK inhibitor (SP600125) or JNK small hairpin RNA (shRNA). The expression levels of Rgs4 mRNA and protein were determined by real-time RT-PCR and Western blot respectively. SP600125 or JNK shRNA increased Rgs4 expression in the absence or presence of IL-1β stimulation. Overexpression of MEKK1, the key upstream kinase of JNK, inhibited Rgs4 expression, which was reversed by co-expression of JNK shRNA or dominant-negative mutants for MKK4 or JNK. Both constitutive and inducible upregulation of Rgs4 expression by SP600125 was significantly inhibited by pretreatment with the transcription inhibitor, actinomycin D. Dual reporter assay showed that pretreatment with SP600125 sensitized the promoter activity of Rgs4 in response to IL-1β. Mutation of the AP1-binding site within Rgs4 promoter increased the promoter activity. Western blot analysis confirmed that IL-1β treatment increased the phosphorylation of JNK, ATF-2 and c-Jun. Gel shift and chromatin immunoprecipitation assays validated that IL-1β increased the in vitro and ex vivo binding activities of AP1 within rabbit Rgs4 promoter. CONCLUSION/SIGNIFICANCE Activation of MEKK1-MKK4-JNK-AP1 signal pathway plays a tonic inhibitory role in regulating Rgs4 transcription in rabbit colonic smooth muscle cells. This negative regulation may aid in maintaining the transient level of RGS4 expression.
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JNK1 inhibits GluR1 expression and GluR1-mediated calcium influx through phosphorylation and stabilization of Hes-1. J Neurosci 2012; 32:1826-46. [PMID: 22302822 DOI: 10.1523/jneurosci.3380-11.2012] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The GluR1 subunit of the AMPA receptor plays an important role in excitatory synaptic transmission and synaptic plasticity in the brain, but the regulation mechanism for GluR1 expression is largely unknown. Hairy and enhancer of split 1 (Hes-1) is a mammalian transcription repressor that regulates neuronal differentiation and development, but the role of Hes-1 in differentiated neurons is also less known. Here, we examined the molecular mechanism in regulation of GluR1 expression in rat cultured cortical neurons. We found that Hes-1 suppressed GluR1 promoter activity and decreased GluR1 expression through direct binding to the N-box and through preventing Mash1/E47 from binding to the E-box of GluR1 promoter. We also found that Hes-1 could be regulated by c-Jun N-terminal kinase (JNK1). JNK1 directly phosphorylates Hes-1 at Ser-263. Furthermore, JNK1 phosphorylation of Hes-1 stabilized the Hes-1 protein and enhanced the suppressing effect of Hes-1 on GluR1 expression. These effects were demonstrated both in the soma and at the synapse. Moreover, this JNK1-mediated signaling pathway was found to inhibit AMPA-evoked calcium influx in cortical neurons and this regulation mechanism is Notch independent. Here, we provided the first evidence that Hes-1 plays an important role in synaptic function in differentiated neurons. We also identified a novel JNK1-Hes-1 signaling pathway that regulates GluR1 expression involved in synaptic function in rat cortical neurons.
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177
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Lau E, Kluger H, Varsano T, Lee K, Scheffler I, Rimm DL, Ideker T, Ronai ZA. PKCε promotes oncogenic functions of ATF2 in the nucleus while blocking its apoptotic function at mitochondria. Cell 2012; 148:543-55. [PMID: 22304920 DOI: 10.1016/j.cell.2012.01.016] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2011] [Revised: 08/12/2011] [Accepted: 01/06/2012] [Indexed: 01/05/2023]
Abstract
The transcription factor ATF2 elicits oncogenic activities in melanoma and tumor suppressor activities in nonmalignant skin cancer. Here, we identify that ATF2 tumor suppressor function is determined by its ability to localize at the mitochondria, where it alters membrane permeability following genotoxic stress. The ability of ATF2 to reach the mitochondria is determined by PKCε, which directs ATF2 nuclear localization. Genotoxic stress attenuates PKCε effect on ATF2; enables ATF2 nuclear export and localization at the mitochondria, where it perturbs the HK1-VDAC1 complex; increases mitochondrial permeability; and promotes apoptosis. Significantly, high levels of PKCε, as seen in melanoma cells, block ATF2 nuclear export and function at the mitochondria, thereby attenuating apoptosis following exposure to genotoxic stress. In melanoma tumor samples, high PKCε levels associate with poor prognosis. Overall, our findings provide the framework for understanding how subcellular localization enables ATF2 oncogenic or tumor suppressor functions.
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Affiliation(s)
- Eric Lau
- Signal Transduction Program, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
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178
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Seong KH, Maekawa T, Ishii S. Inheritance and memory of stress-induced epigenome change: roles played by the ATF-2 family of transcription factors. Genes Cells 2012; 17:249-63. [PMID: 22380515 PMCID: PMC3444692 DOI: 10.1111/j.1365-2443.2012.01587.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Data on the inheritance-of-stress effect have been accumulating and some mechanistic insights, such as epigenetic regulation, have also been suggested. In particular, the modern view of Lamarckian inheritance appears to be affected by the finding that stress-induced epigenetic changes can be inherited. This review summarizes the current data on the inheritance of stress effect and possible mechanisms involved in this process. In particular, we focus on the stress-induced epigenetic changes mediated by the ATF-2 family of transcription factors.
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Affiliation(s)
- Ki-Hyeon Seong
- Laboratory of Molecular Genetics, RIKEN Tsukuba Institute, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan
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Chronic isolation stress compromises JNK/c-Jun signaling in rat brain. J Neural Transm (Vienna) 2012; 119:1275-84. [PMID: 22358066 DOI: 10.1007/s00702-012-0776-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Accepted: 02/08/2012] [Indexed: 01/19/2023]
Abstract
The c-Jun NH2-terminal kinases (JNKs) are important stress-responsive kinases. They regulate cellular activities by sequential phosphorylation and activation through a mitogen-activated protein kinase cascade, whereas JNKs activation is altered in response to various stressors. In the present study, we used immunoblotting to assess the effect of 21 day of social isolation as the chronic stressor, either sole and in combination with 2 h of acute immobilization or cold (4°C) stress on circulating corticosterone level and phosphorylation status of p46 (phospho-p46/total p46) and p54 (phospho-p54/total p54) JNK isoforms in the cytosolic and nuclear fraction of the prefrontal cortex and hippocampus of male Wistar rats. Also, the phosphorylation status of JNK nuclear down-stream target c-Jun (p-c-Jun/c-Jun) on Ser63 was examined. Both acute stressors with elevated CORT levels led to increased phosphorylation status of cytosolic p54 JNK isoforms but not p46 JNK isoforms only in the hippocampus and no change in phosphorylation status of c-jun in both brain regions. Chronic isolation with unaltered CORT level and reduced responsiveness to novel acute stressors, led to unchanged or reduced phosphorylation status of p46 and p54 JNK isoforms in both fractions and both brain regions, whereas the decrease of c-Jun phosphorylation status was found only in the prefrontal cortex. Our results suggest that compromised JNKs activation following chronic isolation may lead to interruption of JNK signaling, which could be related with neuropsychiatric disorders such as depression or long-lasting neuronal remodeling.
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180
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Hsu CC, Hu CD. Critical role of N-terminal end-localized nuclear export signal in regulation of activating transcription factor 2 (ATF2) subcellular localization and transcriptional activity. J Biol Chem 2012; 287:8621-32. [PMID: 22275354 DOI: 10.1074/jbc.m111.294272] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Activating transcription factor 2 (ATF2) belongs to the basic leucine zipper family of transcription factors. ATF2 regulates target gene expression by binding to the cyclic AMP-response element as a homodimer or a heterodimer with c-Jun. Cytoplasmic localization of ATF2 was observed in melanoma, brain tissue from patients with Alzheimer disease, prostate cancer specimens, and ionizing radiation-treated prostate cancer cells, suggesting that alteration of ATF2 subcellular localization may be involved in the pathogenesis of these diseases. We previously demonstrated that ATF2 is a nucleocytoplasmic shuttling protein, and it contains two nuclear localization signals in the basic region and one nuclear export signal (NES) in the leucine zipper domain (named LZ-NES). In the present study, we demonstrate that a hydrophobic stretch in the N terminus, (1)MKFKLHV(7), also functions as an NES (termed N-NES) in a chromosome region maintenance 1 (CRM1)-dependent manner. Mutation of both N-NES and LZ-NES results in a predominant nuclear localization, whereas mutation of each individual NES only partially increases the nuclear localization. These results suggest that cytoplasmic localization of ATF2 requires function of at least one of the NESs. Further, mutation of N-NES enhances the transcriptional activity of ATF2, suggesting that the novel NES negatively regulates the transcriptional potential of ATF2. Thus, ATF2 subcellular localization is probably modulated by multiple mechanisms, and further understanding of the regulation of ATF2 subcellular localization under various pathological conditions will provide insight into the pathophysiological role of ATF2 in human diseases.
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Affiliation(s)
- Chih-Chao Hsu
- Department of Medicinal Chemistry and Molecular Pharmacology and the Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana 47907, USA
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181
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Kannan Y, Wilson MS. TEC and MAPK Kinase Signalling Pathways in T helper (T H) cell Development, T H2 Differentiation and Allergic Asthma. JOURNAL OF CLINICAL & CELLULAR IMMUNOLOGY 2012; Suppl 12:11. [PMID: 24116341 PMCID: PMC3792371 DOI: 10.4172/2155-9899.s12-011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Significant advances in our understanding of the signalling events during T cell development and differentiation have been made in the past few decades. It is clear that ligation of the T cell receptor (TCR) triggers a series of proximal signalling cascades regulated by an array of protein kinases. These orchestrated and highly regulated series of events, with differential requirements of particular kinases, highlight the disparities between αβ+CD4+ T cells. Throughout this review we summarise both new and old studies, highlighting the role of Tec and MAPK in T cell development and differentiation with particular focus on T helper 2 (TH2) cells. Finally, as the allergy epidemic continues, we feature the role played by TH2 cells in the development of allergy and provide a brief update on promising kinase inhibitors that have been tested in vitro, in pre-clinical disease models in vivo and into clinical studies.
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Affiliation(s)
- Yashaswini Kannan
- Division of Molecular Immunology, National Institute for Medical Research, MRC, London, NW7 1AA, UK
| | - Mark S. Wilson
- Division of Molecular Immunology, National Institute for Medical Research, MRC, London, NW7 1AA, UK
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Li G, Yang X, Zhang Y, Liu H, Zhang W, Shen Y, Fan W, Lu Z, Lu D. Comparative proteomics study of freshly isolated, in vitro cultured, and proliferating islet preparation cells. J Endocrinol Invest 2011; 34:816-23. [PMID: 20926920 DOI: 10.3275/7275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND In vitro islet expansion has recently drawn interest for its potential application in diabetes therapy, while how islet cells adapt to in vitro circumstances is not quite clear. AIM Proteomics changes of cultivated islet cells under different conditions were examined in this study. MATERIAL/SUBJECTS AND METHODS A comparative proteomics study was performed on fresh isolated islet cells, cultured cells and in vitro proliferating islet cells stimulated by basic fibroblast growth factor via electrophoresis and liquid chromatography in tandem with mass spectrometry. RESULTS In total, 1897 proteins were identified in this study. Hierarchical analysis revealed substantial changes in the proteome during cultivation but relatively less difference between different culture conditions. Over 100 proteins showed significantly different expression levels between groups, most of which are involved in metabolism or cell process pathways. Overall, the detected proteins were involved in 152 known pathways. Furthermore, in-depth investigation suggested that some proteins, such as extracellular signal-regulated protein kinases and Rac, might play key roles in the proliferation, apoptosis, and differentiation of in vitro cultured islet cells. CONCLUSION We established comparative proteome references of fresh and cultured islet cells, which could provide useful information for future islet transplantation strategy.
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Affiliation(s)
- G Li
- The State Key Laboratory of Genetic Engineering and The MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China
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183
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Yamagata K, Li X, Ikegaki S, Oneyama C, Okada M, Nishita M, Minami Y. Dissection of Wnt5a-Ror2 signaling leading to matrix metalloproteinase (MMP-13) expression. J Biol Chem 2011; 287:1588-99. [PMID: 22128168 DOI: 10.1074/jbc.m111.315127] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
It has been shown that constitutively active Wnt5a-Ror2 signaling in osteosarcoma cell lines plays crucial roles in induced expression of matrix metalloproteinase-13 (MMP-13), required for their invasiveness; however, it remains largely unclear about the molecular basis of MMP-13 gene induction by Wnt5a-Ror2 signaling. Here we show by reporter assay that the activator protein 1 (AP1) (binding site in the promoter region of MMP-13 gene is primarily responsible for its transcriptional activation by Wnt5a-Ror2 signaling in osteosarcoma cell lines SaOS-2 and U2OS. Chromatin immunoprecipitation assays revealed that c-Jun and ATF2 are crucial transcription factors recruited to the AP1-binding site in the MMP-13 gene promoter during Wnt5a-Ror2 signaling in SaOS-2 cells. Using siRNA-mediated suppression or specific inhibitors, we also show that Dishevelled2 (Dvl2) and c-Jun N-terminal kinase are required for MMP-13 gene induction presumably via phosphorylation of c-Jun and ATF2 during Wnt5a-Ror2 signaling in SaOS-2 cells. Interestingly, Dvl2 and Rac1, but not Dvl3, are required for MMP-13 expression in SaOS-2 cells, whereas Dvl3, but not Dvl2 and Rac1, is required for its expression in U2OS cells, indicating the presence of distinct intracellular signaling machineries leading to expression of the same gene, in this case MMP-13 gene in different osteosarcoma cell lines. Moreover, we provide evidence suggesting that Wnt5a-Ror2 signaling might also be required for expression of MMP-13 gene during the development of the cartilaginous tissue.
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Affiliation(s)
- Kaoru Yamagata
- Department of Physiology and Cell Biology, Graduate School of Medicine, Kobe University, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan
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184
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Chi J, Wang F, Li L, Feng D, Qin J, Xie F, Zhou F, Chen Y, Wang J, Yao K. The role of MAPK in CD4(+) T cells toll-like receptor 9-mediated signaling following HHV-6 infection. Virology 2011; 422:92-8. [PMID: 22055432 DOI: 10.1016/j.virol.2011.09.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 09/07/2011] [Accepted: 09/28/2011] [Indexed: 10/15/2022]
Abstract
Human herpesvirus-6 (HHV-6) is an important immunosuppressive and immunomodulatory virus that primarily infects immune cells (mainly CD4(+) T cells) and strongly suppresses the proliferation of infected cells. Toll-like receptors are pattern-recognition receptors essential for the development of an appropriate innate immune defense against infection. To understand the role of CD4(+) T cells in the innate response to HHV-6 infection and the involvement of TLRs, we used an in vitro infection model and observed that the infection of CD4(+) T cells resulted in the activation of JNK/SAPK via up-regulation of toll-like receptor 9 (TLR9). Associated with JNK activation, annexin V-PI staining indicated that HHV-6A was a strong inducer of apoptosis. Apoptotic response associated cytokines, IL-6 and TNF-α also induced by HHV-6A infection.
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Affiliation(s)
- Jing Chi
- Department of Microbiology and Immunology, Nanjing Medical University, Nanjing 210029, Jiangsu Province, China
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185
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Abstract
Tumor necrosis factor receptor (TNFR) superfamily members mediate the cellular response to a wide variety of biological inputs. The responses range from cell death, survival, differentiation, proliferation, to the regulation of immunity. All these physiological responses are regulated by a limited number of highly pleiotropic kinases. The fact that the same signaling molecules are involved in transducing signals from TNFR superfamily members that regulate different and even opposing processes raises the question of how their specificity is determined. Regulatory strategies that can contribute to signaling specificity include scaffolding to control kinase specificity, combinatorial use of several signal transducers, and temporal control of signaling. In this review, we discuss these strategies in the context of TNFR superfamily member signaling.
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Affiliation(s)
- Bärbel Schröfelbauer
- Signaling Systems Laboratory, Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093-0375, USA.
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186
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Song N, Kim SJ, Kwon HY, Son SW, Kim KS, Ahn HB, Lee YC. Transcriptional activation of human GM3 synthase (hST3Gal V) gene by valproic acid in ARPE-19 human retinal pigment epithelial cells. BMB Rep 2011; 44:405-9. [PMID: 21699754 DOI: 10.5483/bmbrep.2011.44.6.405] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The present study demonstrated that valproic acid (VPA) transcriptionally regulates human GM3 synthase (hST3Gal V), which catalyzes ganglioside GM3 biosynthesis in ARPE-19 human retinal pigment epithelial cells. For this, we characterized the promoter region of the hST3Gal V gene. Functional analysis of the 5'-flanking region of the hST3Gal V gene revealed that the -177 to -83 region functions as the VPA-inducible promoter and that the CREB/ATF binding site at -143 is crucial for VPA-induced expression of hST3Gal V in ARPE-19 cells. In addition, the transcriptional activity of hST3Gal V induced by VPA in ARPE-19 cells was inhibited by SP600125, a c-Jun N-terminal kinase (JNK) inhibitor. In summary, our results identified the core promoter region in the hST3Gal V promoter and for the first time demonstrated that ATF2 binding to the CREB/ATF binding site at -143 is essential for transcriptional activation of hST3Gal V in VPA-induced ARPE-19 cells.
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Affiliation(s)
- Naree Song
- Department of Biotechnology and Brain Korea 21 Center for Silver-Bio Industrialization, Dong-A University, Busan 604-714, Korea
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187
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Terai K, Call MK, Liu H, Saika S, Liu CY, Hayashi Y, Chikama TI, Zhang J, Terai N, Kao CWC, Kao WWY. Crosstalk between TGF-beta and MAPK signaling during corneal wound healing. Invest Ophthalmol Vis Sci 2011; 52:8208-15. [PMID: 21917935 DOI: 10.1167/iovs.11-8017] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The aim of this study was to elucidate the mechanisms governing epithelial cell migration and proliferation during wound healing. METHODS The authors used wound healing of mouse corneal epithelium to examine the role TGF-β signaling plays during the healing process. To achieve this goal, they used transgenic mice in which the TGF-β receptor type II (Tbr2) was conditionally ablated from the corneal epithelium. Epithelium debridement wounds were made, followed by the assessment of cell migration, proliferation, and immunostaining of various signaling pathway components. RESULTS The authors showed that in the absence of TGF-β signaling corneal epithelial wound healing is delayed by 48 hours; this corresponds to a delay in p38MAPK activation. Despite the delayed p38MAPK activation, ATF2, a substrate of p38MAPK, is still phosphorylated, leading to the suppression of cell proliferation at the leading edge of the wound. These data provide evidence that in the absence of TGF-β signaling, the suppression of cell proliferation during the early stages of wound healing is maintained through the JNK activation of ATF2. CONCLUSIONS; Together the data presented here demonstrate the importance of the TGF-β and MAPK signaling pathways in corneal epithelial wound healing.
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Affiliation(s)
- Kazuto Terai
- Department of Ophthalmology, University of Cincinnati, Cincinnati, Ohio 45267-0838, USA
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188
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Chen MB, Wu XY, Gu JH, Guo QT, Shen WX, Lu PH. Activation of AMP-activated protein kinase contributes to doxorubicin-induced cell death and apoptosis in cultured myocardial H9c2 cells. Cell Biochem Biophys 2011; 60:311-22. [PMID: 21274754 DOI: 10.1007/s12013-011-9153-0] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Despite its potent antitumor effect, clinical use of Doxorubicin is limited because of serious side effects including myocardial toxicity. Understanding the cellular mechanism involved in this process in a better manner is beneficial for optimizing Doxorubicin treatment. In the current study, the authors focus on the AMP-activated protein kinase (AMPK) in the said process. In this study, the authors discovered for the first time that Doxorubicin induces AMPK activation in cultured rat embryonic ventricular myocardial H9c2 cells. Reactive oxygen species (ROS)-dependent LKB1 activation serves as the upstream signal for AMPK activation by Doxorubicin. Evidence in support of the activation of AMPK contributing to Doxorubicin-induced H9c2 cell death/apoptosis--probably by modulating multiple downstream signal targets, including regulating JNK, p53, and inhibiting mTORC1--is provided in this article.
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Affiliation(s)
- Min-Bin Chen
- Department of Medical Oncology, Kunshan First People's Hospital Affiliated to Jiangsu University, 91 Qianjin Road, Kunshan 215300, Jiangsu Province, China.
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189
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Seong KH, Li D, Shimizu H, Nakamura R, Ishii S. Inheritance of stress-induced, ATF-2-dependent epigenetic change. Cell 2011; 145:1049-61. [PMID: 21703449 DOI: 10.1016/j.cell.2011.05.029] [Citation(s) in RCA: 220] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Revised: 03/16/2011] [Accepted: 05/23/2011] [Indexed: 11/17/2022]
Abstract
Atf1, the fission yeast homolog of activation transcription factor-2 (ATF-2), contributes to heterochromatin formation. However, the role of ATF-2 in chromatin assembly in higher organisms remains unknown. This study reveals that Drosophila ATF-2 (dATF-2) is required for heterochromatin assembly, whereas the stress-induced phosphorylation of dATF-2, via Mekk1-p38, disrupts heterochromatin. The dATF-2 protein colocalized with HP1, not only on heterochromatin but also at specific loci in euchromatin. Heat shock or osmotic stress induced phosphorylation of dATF-2 and resulted in its release from heterochromatin. This heterochromatic disruption was an epigenetic event that was transmitted to the next generation in a non-Mendelian fashion. When embryos were exposed to heat stress over multiple generations, the defective chromatin state was maintained over multiple successive generations, though it gradually returned to the normal state. The results suggest a mechanism by which the effects of stress are inherited epigenetically via the regulation of a tight chromatin structure.
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Affiliation(s)
- Ki-Hyeon Seong
- Laboratory of Molecular Genetics, RIKEN Tsukuba Institute, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan
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190
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Diring J, Camuzeaux B, Donzeau M, Vigneron M, Rosa-Calatrava M, Kedinger C, Chatton B. A cytoplasmic negative regulator isoform of ATF7 impairs ATF7 and ATF2 phosphorylation and transcriptional activity. PLoS One 2011; 6:e23351. [PMID: 21858082 PMCID: PMC3156760 DOI: 10.1371/journal.pone.0023351] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Accepted: 07/13/2011] [Indexed: 11/18/2022] Open
Abstract
Alternative splicing and post-translational modifications are processes that give rise to the complexity of the proteome. The nuclear ATF7 and ATF2 (activating transcription factor) are structurally homologous leucine zipper transcription factors encoded by distinct genes. Stress and growth factors activate ATF2 and ATF7 mainly via sequential phosphorylation of two conserved threonine residues in their activation domain. Distinct protein kinases, among which mitogen-activated protein kinases (MAPK), phosphorylate ATF2 and ATF7 first on Thr71/Thr53 and next on Thr69/Thr51 residues respectively, resulting in transcriptional activation. Here, we identify and characterize a cytoplasmic alternatively spliced isoform of ATF7. This variant, named ATF7-4, inhibits both ATF2 and ATF7 transcriptional activities by impairing the first phosphorylation event on Thr71/Thr53 residues. ATF7-4 indeed sequesters the Thr53-phosphorylating kinase in the cytoplasm. Upon stimulus-induced phosphorylation, ATF7-4 is poly-ubiquitinated and degraded, enabling the release of the kinase and ATF7/ATF2 activation. Our data therefore conclusively establish that ATF7-4 is an important cytoplasmic negative regulator of ATF7 and ATF2 transcription factors.
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Affiliation(s)
- Jessica Diring
- Université de Strasbourg, UMR7242 Biotechnologie et Signalisation Cellulaire, Ecole Supérieure de Biotechnologie de Strasbourg, BP10413, Illkirch, France
| | - Barbara Camuzeaux
- Université de Strasbourg, UMR7242 Biotechnologie et Signalisation Cellulaire, Ecole Supérieure de Biotechnologie de Strasbourg, BP10413, Illkirch, France
| | - Mariel Donzeau
- Université de Strasbourg, UMR7242 Biotechnologie et Signalisation Cellulaire, Ecole Supérieure de Biotechnologie de Strasbourg, BP10413, Illkirch, France
| | - Marc Vigneron
- Université de Strasbourg, UMR7242 Biotechnologie et Signalisation Cellulaire, Ecole Supérieure de Biotechnologie de Strasbourg, BP10413, Illkirch, France
| | - Manuel Rosa-Calatrava
- Laboratoire de Virologie et Pathologie Humaine VirPath, Université Claude Bernard Lyon 1, Hospices Civils de Lyon, Lyon, France
| | - Claude Kedinger
- Université de Strasbourg, UMR7242 Biotechnologie et Signalisation Cellulaire, Ecole Supérieure de Biotechnologie de Strasbourg, BP10413, Illkirch, France
| | - Bruno Chatton
- Université de Strasbourg, UMR7242 Biotechnologie et Signalisation Cellulaire, Ecole Supérieure de Biotechnologie de Strasbourg, BP10413, Illkirch, France
- * E-mail:
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191
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Mohamed BM, Verma NK, Prina-Mello A, Williams Y, Davies AM, Bakos G, Tormey L, Edwards C, Hanrahan J, Salvati A, Lynch I, Dawson K, Kelleher D, Volkov Y. Activation of stress-related signalling pathway in human cells upon SiO2 nanoparticles exposure as an early indicator of cytotoxicity. J Nanobiotechnology 2011; 9:29. [PMID: 21801388 PMCID: PMC3164618 DOI: 10.1186/1477-3155-9-29] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Accepted: 07/29/2011] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Nanomaterials such as SiO2 nanoparticles (SiO2NP) are finding increasing applications in the biomedical and biotechnological fields such as disease diagnostics, imaging, drug delivery, food, cosmetics and biosensors development. Thus, a mechanistic and systematic evaluation of the potential biological and toxic effects of SiO2NP becomes crucial in order to assess their complete safe applicability limits. RESULTS In this study, human monocytic leukemia cell line THP-1 and human alveolar epithelial cell line A549 were exposed to a range of amorphous SiO2NP of various sizes and concentrations (0.01, 0.1 and 0.5 mg/ml). Key biological indicators of cellular functions including cell population density, cellular morphology, membrane permeability, lysosomal mass/pH and activation of transcription factor-2 (ATF-2) were evaluated utilizing quantitative high content screening (HCS) approach and biochemical techniques. Despite the use of extremely high nanoparticle concentrations, our findings showed a low degree of cytotoxicity within the panel of SiO2NP investigated. However, at these concentrations, we observed the onset of stress-related cellular response induced by SiO2NP. Interestingly, cells exposed to alumina-coated SiO2NP showed low level, and in some cases complete absence, of stress response and this was consistent up to the highest dose of 0.5 mg/ml. CONCLUSIONS The present study demonstrates and highlights the importance of subtle biological changes downstream of primary membrane and endocytosis-associated phenomena resulting from high dose SiO2NP exposure. Increased activation of transcription factors, such as ATF-2, was quantitatively assessed as a function of i) human cell line specific stress-response, ii) SiO2NP size and iii) concentration. Despite the low level of cytotoxicity detected for the amorphous SiO2NP investigated, these findings prompt an in-depth focus for future SiO2NP-cell/tissue investigations based on the combined analysis of more subtle signalling pathways associated with accumulation mechanisms, which is essential for establishing the bio-safety of existing and new nanomaterials.
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Affiliation(s)
- Bashir Mustafa Mohamed
- Department of clinical medicine, Institute of Molecular Medicine, Trinity College Dublin, Dublin8, Ireland
| | - Navin Kumar Verma
- Department of clinical medicine, Institute of Molecular Medicine, Trinity College Dublin, Dublin8, Ireland
| | - Adriele Prina-Mello
- Department of clinical medicine, Institute of Molecular Medicine, Trinity College Dublin, Dublin8, Ireland
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Naughton Institute, Trinity College Dublin, Dublin2, Ireland
| | - Yvonne Williams
- Department of clinical medicine, Institute of Molecular Medicine, Trinity College Dublin, Dublin8, Ireland
| | - Anthony M Davies
- Department of clinical medicine, Institute of Molecular Medicine, Trinity College Dublin, Dublin8, Ireland
| | - Gabor Bakos
- Department of clinical medicine, Institute of Molecular Medicine, Trinity College Dublin, Dublin8, Ireland
| | - Laragh Tormey
- Department of clinical medicine, Institute of Molecular Medicine, Trinity College Dublin, Dublin8, Ireland
| | - Connla Edwards
- Department of clinical medicine, Institute of Molecular Medicine, Trinity College Dublin, Dublin8, Ireland
| | - John Hanrahan
- Glantreo Ltd., Environmental Research Institute (ERI) Building, Lee Road, Cork, Ireland
| | - Anna Salvati
- Centre for BioNano Interactions, School of Chemistry and Chemical Biology, University College Dublin, Dublin4, Ireland
| | - Iseult Lynch
- Centre for BioNano Interactions, School of Chemistry and Chemical Biology, University College Dublin, Dublin4, Ireland
| | - Kenneth Dawson
- Centre for BioNano Interactions, School of Chemistry and Chemical Biology, University College Dublin, Dublin4, Ireland
| | - Dermot Kelleher
- Department of clinical medicine, Institute of Molecular Medicine, Trinity College Dublin, Dublin8, Ireland
| | - Yuri Volkov
- Department of clinical medicine, Institute of Molecular Medicine, Trinity College Dublin, Dublin8, Ireland
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Naughton Institute, Trinity College Dublin, Dublin2, Ireland
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192
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Bachstetter AD, Xing B, de Almeida L, Dimayuga ER, Watterson DM, Van Eldik LJ. Microglial p38α MAPK is a key regulator of proinflammatory cytokine up-regulation induced by toll-like receptor (TLR) ligands or beta-amyloid (Aβ). J Neuroinflammation 2011; 8:79. [PMID: 21733175 PMCID: PMC3142505 DOI: 10.1186/1742-2094-8-79] [Citation(s) in RCA: 191] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Accepted: 07/06/2011] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Overproduction of proinflammatory cytokines from activated microglia has been implicated as an important contributor to pathophysiology progression in both acute and chronic neurodegenerative diseases. Therefore, it is critical to elucidate intracellular signaling pathways that are significant contributors to cytokine overproduction in microglia exposed to specific stressors, especially pathways amenable to drug interventions. The serine/threonine protein kinase p38α MAPK is a key enzyme in the parallel and convergent intracellular signaling pathways involved in stressor-induced production of IL-1β and TNFα in peripheral tissues, and is a drug development target for peripheral inflammatory diseases. However, much less is known about the quantitative importance of microglial p38α MAPK in stressor-induced cytokine overproduction, or the potential of microglial p38α MAPK to be a druggable target for CNS disorders. Therefore, we examined the contribution of microglial p38αMAPK to cytokine up-regulation, with a focus on the potential to suppress the cytokine increase by inhibition of the kinase with pharmacological or genetic approaches. METHODS The microglial cytokine response to TLR ligands 2/3/4/7/8/9 or to Aβ1-42 was tested in the presence of a CNS-penetrant p38α MAPK inhibitor, MW01-2-069A-SRM. Primary microglia from mice genetically deficient in p38α MAPK were used to further establish a linkage between microglia p38α MAPK and cytokine overproduction. The in vivo significance was determined by p38α MAPK inhibitor treatment in a LPS-induced model of acute neuroinflammation. RESULTS Increased IL-1β and TNFα production by the BV-2 microglial cell line and by primary microglia cultures was inhibited in a concentration-dependent manner by the p38α MAPK-targeted inhibitor. Cellular target engagement was demonstrated by the accompanying decrease in the phosphorylation state of two p38α MAPK protein substrates, MK2 and MSK1. Consistent with the pharmacological findings, microglia from p38α-deficient mice showed a diminished cytokine response to LPS. Further, oral administration of the inhibitor blocked the increase of IL-1β in the cerebral cortex of mice stressed by intraperitoneal injection of LPS. CONCLUSION The p38α MAPK pathway is an important contributor to the increased microglial production of proinflammatory cytokines induced by diverse stressors. The results also indicate the feasibility of targeting p38α MAPK to modulate CNS proinflammatory cytokine overproduction.
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Affiliation(s)
- Adam D Bachstetter
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
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193
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Mathiasen DP, Egebjerg C, Andersen SH, Rafn B, Puustinen P, Khanna A, Daugaard M, Valo E, Tuomela S, Bøttzauw T, Nielsen CF, Willumsen BM, Hautaniemi S, Lahesmaa R, Westermarck J, Jäättelä M, Kallunki T. Identification of a c-Jun N-terminal kinase-2-dependent signal amplification cascade that regulates c-Myc levels in ras transformation. Oncogene 2011; 31:390-401. [PMID: 21706057 DOI: 10.1038/onc.2011.230] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Ras is one of the most frequently activated oncogenes in cancer. Two mitogen-activated protein kinases (MAPKs) are important for ras transformation: extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase 2 (JNK2). Here we present a downstream signal amplification cascade that is critical for ras transformation in murine embryonic fibroblasts. This cascade is coordinated by ERK and JNK2 MAPKs, whose Ras-mediated activation leads to the enhanced levels of three oncogenic transcription factors, namely, c-Myc, activating transcription factor 2 (ATF2) and ATF3, all of which are essential for ras transformation. Previous studies show that ERK-mediated serine 62 phosphorylation protects c-Myc from proteasomal degradation. ERK is, however, not alone sufficient to stabilize c-Myc but requires the cooperation of cancerous inhibitor of protein phosphatase 2A (CIP2A), an oncogene that counteracts protein phosphatase 2A-mediated dephosphorylation of c-Myc. Here we show that JNK2 regulates Cip2a transcription via ATF2. ATF2 and c-Myc cooperate to activate the transcription of ATF3. Remarkably, not only ectopic JNK2, but also ectopic ATF2, CIP2A, c-Myc and ATF3 are sufficient to rescue the defective ras transformation of JNK2-deficient cells. Thus, these data identify the key signal converging point of JNK2 and ERK pathways and underline the central role of CIP2A in ras transformation.
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Affiliation(s)
- D P Mathiasen
- Apoptosis Department and Centre for Genotoxic Stress Research, Institute of Cancer Biology, Danish Cancer Society, Copenhagen, Denmark
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194
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Wang H, Song W, Hu T, Zhang N, Miao S, Zong S, Wang L. Fank1 interacts with Jab1 and regulates cell apoptosis via the AP-1 pathway. Cell Mol Life Sci 2011; 68:2129-39. [PMID: 20978819 PMCID: PMC11114715 DOI: 10.1007/s00018-010-0559-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Revised: 09/15/2010] [Accepted: 10/05/2010] [Indexed: 10/18/2022]
Abstract
Regulation of apoptosis at various stages of differentiation plays an important role in spermatogenesis. Therefore, the identification and characterisation of highly expressed genes in the testis that are involved in apoptosis is of great value to delineate the mechanism of spermatogenesis. Here, we reported that Fank1, a novel gene highly expressed in testis, functioned as an anti-apoptotic protein that activated the activator protein 1 (AP-1) pathway. We found that Jab1 (Jun activation domain-binding protein 1), a co-activator of AP-1, specifically interacted with Fank1. Reporter analyses showed that Fank1 activated AP-1 pathway in a Jab1-dependent manner. Fank1 overexpression also increased the expression and activation of endogenous c-Jun. Further study showed that Fank1 inhibited cell apoptosis by upregulating and activating endogenous c-Jun and its downstream target, Bcl-3. This process was shown to be Jab1 dependent. Taken together, our results indicated that by interacting with Jab1, Fank1 could suppress cell apoptosis by activating the AP-1-induced anti-apoptotic pathway.
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Affiliation(s)
- Hailong Wang
- National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Tsinghua University, 5 Dong Dan San Tiao, Beijing, 100005 China
- Academy of Basic Medicine, Shanxi Medical University, 56 Xin Jian Nan Lu, Taiyuan, 030001 China
| | - Wei Song
- National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Tsinghua University, 5 Dong Dan San Tiao, Beijing, 100005 China
| | - Tinghui Hu
- National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Tsinghua University, 5 Dong Dan San Tiao, Beijing, 100005 China
| | - Ning Zhang
- National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Tsinghua University, 5 Dong Dan San Tiao, Beijing, 100005 China
| | - Shiying Miao
- National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Tsinghua University, 5 Dong Dan San Tiao, Beijing, 100005 China
| | - Shudong Zong
- National Research Institute for Family Planning Beijing, WHO Collaboration Center of Human Reproduction, 12 Da Hui Si, Hai Dian, Beijing, 100081 China
| | - Linfang Wang
- National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Tsinghua University, 5 Dong Dan San Tiao, Beijing, 100005 China
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195
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Wen HC, Avivar-Valderas A, Sosa MS, Girnius N, Farias EF, Davis RJ, Aguirre-Ghiso JA. p38α Signaling Induces Anoikis and Lumen Formation During Mammary Morphogenesis. Sci Signal 2011; 4:ra34. [PMID: 21610252 DOI: 10.1126/scisignal.2001684] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The stress-activated protein kinase (SAPK) p38 can induce apoptosis, and its inhibition facilitates mammary tumorigenesis. We found that during mammary acinar morphogenesis in MCF-10A cells grown in three-dimensional culture, detachment of luminal cells from the basement membrane stimulated mitogen-activated protein kinase (MAPK) kinases 3 and 6 (MKK3/6) and p38α signaling to promote anoikis. p38α signaling increased transcription of the death-promoting protein BimEL by phosphorylating the activating transcription factor 2 (ATF-2) and increasing c-Jun protein abundance, leading to cell death by anoikis and acinar lumen formation. Inhibition of p38α or ATF-2 caused luminal filling reminiscent of that observed in ductal carcinoma in situ (DCIS). The mammary glands of MKK3/6 knockout mice (MKK3(-/-)/MKK6(+/- )) showed accelerated branching morphogenesis relative to those of wild-type mice, as well as ductal lumen occlusion due to reduced anoikis. This phenotype was recapitulated by systemic pharmacological inhibition of p38α and β (p38α/β) in wild-type mice. Moreover, the development of DCIS-like lesions showing marked ductal occlusion was accelerated in MMTV-Neu transgenic mice treated with inhibitors of p38α and p38β. We conclude that p38α is crucial for the development of hollow ducts during mammary gland development, a function that may be crucial to its ability to suppress breast cancer.
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Affiliation(s)
- Huei-Chi Wen
- Department of Medicine, Tisch Cancer Institute at Mount Sinai, Mount Sinai School of Medicine, New York, USA
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196
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Ray RM, Jin S, Bavaria MN, Johnson LR. Regulation of JNK activity in the apoptotic response of intestinal epithelial cells. Am J Physiol Gastrointest Liver Physiol 2011; 300:G761-70. [PMID: 21350193 PMCID: PMC3094148 DOI: 10.1152/ajpgi.00405.2010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We have studied apoptosis of gastrointestinal epithelial cells by examining the receptor-mediated and DNA damage-induced pathways using TNF-α and camptothecin (CPT), respectively. TNF-α requires inhibition of antiapoptotic protein synthesis by cycloheximide (CHX). CHX also results in high levels of active JNK, which are necessary for TNF-induced apoptosis. While CPT induces apoptosis, the increase in JNK activity was not proportional to the degree of apoptosis. Thus the mechanism of activation of JNK and its role in apoptosis are unclear. We examined the course of JNK activation in response to a combination of TNF-α and CPT (TNF + CPT), which resulted in a three- to fourfold increase in apoptosis compared with CPT alone, indicating an amplification of apoptotic signaling pathways. TNF + CPT caused apoptosis by activating JNK, p38, and caspases-8, -9, and -3. TNF-α stimulated a transient phosphorylation of JNK1/2 and ERK1/2 at 15 min, which returned to basal by 60 min and remained low for 4 h. CPT increased JNK1/2 activity between 3 and 4 h. TNF + CPT caused a sustained and robust JNK1/2 and ERK1/2 phosphorylation by 2 h, which remained high at 4 h, suggesting involvement of MEKK4/7 and MEK1, respectively. When administered with TNF + CPT, SP-600125, a specific inhibitor of MEKK4/7, completely inhibited JNK1/2 and decreased apoptosis. However, administration of SP-600125 at 1 h after TNF + CPT failed to prevent JNK1/2 phosphorylation, and the protective effect of SP-600125 on apoptosis was abolished. These results indicate that the persistent activation of JNK might be due to inhibition of JNK-specific MAPK phosphatase 1 (MKP1). Small interfering RNA-mediated knockdown of MKP1 enhanced TNF + CPT-induced activity of JNK1/2 and caspases-9 and -3. Taken together, these results suggest that MKP1 activity determines the duration of JNK1/2 and p38 activation and, thereby, apoptosis in response to TNF + CPT.
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Affiliation(s)
- Ramesh M. Ray
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Shi Jin
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Mitulkumar N. Bavaria
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Leonard R. Johnson
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee
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Yu Y, Richardson DR. Cellular iron depletion stimulates the JNK and p38 MAPK signaling transduction pathways, dissociation of ASK1-thioredoxin, and activation of ASK1. J Biol Chem 2011; 286:15413-27. [PMID: 21378396 PMCID: PMC3083220 DOI: 10.1074/jbc.m111.225946] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Revised: 02/24/2011] [Indexed: 12/27/2022] Open
Abstract
The role of signaling pathways in the regulation of cellular iron metabolism is becoming increasingly recognized. Iron chelation is used for the treatment of iron overload but also as a potential strategy for cancer therapy, because iron depletion results in cell cycle arrest and apoptosis. This study examined potential signaling pathways affected by iron depletion induced by desferrioxamine (DFO) or di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone (Dp44mT). Both chelators affected multiple molecules in the mitogen-activated protein kinase (MAPK) pathway, including a number of dual specificity phosphatases that directly de-phosphorylate MAPKs. Examination of the phosphorylation of major MAPKs revealed that DFO and Dp44mT markedly increased phosphorylation of stress-activated protein kinases, JNK and p38, without significantly affecting the extracellular signal-regulated kinase (ERK). Redox-inactive DFO-iron complexes did not affect phosphorylation of JNK or p38, whereas the redox-active Dp44mT-iron complex significantly increased the phosphorylation of these kinases similarly to Dp44mT alone. Iron or N-acetylcysteine supplementation reversed Dp44mT-induced up-regulation of phospho-JNK, but only iron was able to reverse the effect of DFO on JNK. Both iron chelators significantly reduced ASK1-thioredoxin complex formation, resulting in the increased phosphorylation of ASK1, which activates the JNK and p38 pathways. Thus, dissociation of ASK1 could serve as an important signal for the phosphorylation of JNK and p38 activation observed after iron chelation. Phosphorylation of JNK and p38 likely play an important role in mediating the cell cycle arrest and apoptosis induced by iron depletion.
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Affiliation(s)
- Yu Yu
- From the Iron Metabolism and Chelation Program, Department of Pathology and Bosch Institute, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Des R. Richardson
- From the Iron Metabolism and Chelation Program, Department of Pathology and Bosch Institute, University of Sydney, Sydney, New South Wales 2006, Australia
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198
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Ackermann J, Ashton G, Lyons S, James D, Hornung JP, Jones N, Breitwieser W. Loss of ATF2 function leads to cranial motoneuron degeneration during embryonic mouse development. PLoS One 2011; 6:e19090. [PMID: 21533046 PMCID: PMC3080913 DOI: 10.1371/journal.pone.0019090] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Accepted: 03/28/2011] [Indexed: 01/08/2023] Open
Abstract
The AP-1 family transcription factor ATF2 is essential for development and tissue maintenance in mammals. In particular, ATF2 is highly expressed and activated in the brain and previous studies using mouse knockouts have confirmed its requirement in the cerebellum as well as in vestibular sense organs. Here we present the analysis of the requirement for ATF2 in CNS development in mouse embryos, specifically in the brainstem. We discovered that neuron-specific inactivation of ATF2 leads to significant loss of motoneurons of the hypoglossal, abducens and facial nuclei. While the generation of ATF2 mutant motoneurons appears normal during early development, they undergo caspase-dependent and independent cell death during later embryonic and foetal stages. The loss of these motoneurons correlates with increased levels of stress activated MAP kinases, JNK and p38, as well as aberrant accumulation of phosphorylated neurofilament proteins, NF-H and NF-M, known substrates for these kinases. This, together with other neuropathological phenotypes, including aberrant vacuolisation and lipid accumulation, indicates that deficiency in ATF2 leads to neurodegeneration of subsets of somatic and visceral motoneurons of the brainstem. It also confirms that ATF2 has a critical role in limiting the activities of stress kinases JNK and p38 which are potent inducers of cell death in the CNS.
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Affiliation(s)
- Julien Ackermann
- Cell Regulation Department, Paterson Institute for Cancer Research, University of Manchester, Manchester, United Kingdom
- Institut de Biologie Cellulaire et de Morphologie, Lausanne, Switzerland
| | - Garry Ashton
- Cell Regulation Department, Paterson Institute for Cancer Research, University of Manchester, Manchester, United Kingdom
| | - Steve Lyons
- Cell Regulation Department, Paterson Institute for Cancer Research, University of Manchester, Manchester, United Kingdom
| | - Dominic James
- Cell Regulation Department, Paterson Institute for Cancer Research, University of Manchester, Manchester, United Kingdom
| | | | - Nic Jones
- Cell Regulation Department, Paterson Institute for Cancer Research, University of Manchester, Manchester, United Kingdom
| | - Wolfgang Breitwieser
- Cell Regulation Department, Paterson Institute for Cancer Research, University of Manchester, Manchester, United Kingdom
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199
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Verkaar F, van der Doelen A, Smits J, Blankesteijn W, Zaman G. Inhibition of Wnt/β-Catenin Signaling by p38 MAP Kinase Inhibitors Is Explained by Cross-Reactivity with Casein Kinase Iδ/ɛ. ACTA ACUST UNITED AC 2011; 18:485-94. [DOI: 10.1016/j.chembiol.2011.01.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2010] [Revised: 12/13/2010] [Accepted: 01/26/2011] [Indexed: 12/01/2022]
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200
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Coskun M, Olsen J, Seidelin JB, Nielsen OH. MAP kinases in inflammatory bowel disease. Clin Chim Acta 2011; 412:513-20. [DOI: 10.1016/j.cca.2010.12.020] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 12/16/2010] [Accepted: 12/17/2010] [Indexed: 12/16/2022]
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