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Hidenori Ichijo - One of the best experts on this subject based on the ideXlab platform.
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functional cooperation between ASK1 and p21waf1 cip1 in the balance of cell cycle arrest cell death and tumorigenesis of stressed keratinocytes
Cell death discovery, 2021Co-Authors: Carlo De Blasio, Nagendra Verma, Marta Moretti, Samantha Cialfi, Azzurra Zonfrilli, Matteo Franchitto, Federica Truglio, Enrico De Smaele, Hidenori IchijoAbstract:Both CDKN1A (p21 Waf1/Cip1) and Apoptosis signal-regulating kinase 1 (ASK1) play important roles in tumorigenesis. The role of p21 Waf1/Cip1 in attenuating ASK1-induced apoptosis by various stress conditions is well established. However, how ASK1 and p21 Waf1/Cip1 functionally interact during tumorigenesis is still unclear. To address this aspect, we crossed ASK1 knockout (ASK1KO) mice with p21 Waf1/Cip1 knockout (p21KO) mice to compare single and double-mutant mice. We observed that deletion of p21 Waf1/Cip1 leads to increased keratinocyte proliferation but also increased cell death. This is mechanistically linked to the ASK1 axis-induced apoptosis, including p38 and PARP. Indeed, deletion of ASK1 does not alter the proliferation but decreases the apoptosis of p21KO keratinocytes. To analyze as this interaction might affect skin carcinogenesis, we investigated the response of ASK1KO and p21KO mice to DMBA/TPA-induced tumorigenesis. Here we show that while endogenous ASK1 is dispensable for skin homeostasis, ASK1KO mice are resistant to DMBA/TPA-induced tumorigenesis. However, we found that epidermis lacking both p21 and ASK1 reacquires increased sensitivity to DMBA/TPA-induced tumorigenesis. We demonstrate that apoptosis and cell-cycle progression in p21KO keratinocytes are uncoupled in the absence of ASK1. These data support the model that a critical event ensuring the balance between cell death, cell-cycle arrest, and successful divisions in keratinocytes during stress conditions is the p21-dependent ASK1 inactivation.
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ASK1 regulates murine platelet granule secretion thromboxane a2 generation and thrombus formation
Blood, 2017Co-Authors: Meghna U Naik, Kalyan Golla, Pravin Patel, Hidenori Ichijo, Randall Derstine, Ramya Turaga, Xi Chen, Keith B Neeves, Ulhas P NaikAbstract:Mitogen-activated protein kinases (MAPKs) are expressed in platelets and are activated downstream of physiological agonists. Pharmacological and genetic evidence indicate that MAPKs play a significant role in hemostasis and thrombosis, but it is not well understood how MAPKs are activated upon platelet stimulation. Here, we show that apoptosis signal-regulating kinase 1 (ASK1), a member of the MAP3K family, is expressed in both human and murine platelets. ASK1 is rapidly and robustly activated upon platelet stimulation by physiological agonists. Disruption of ASK1 (ASK1-/- ) resulted in a marked functional defect in platelets. ASK1-/- platelets showed an impaired agonist-induced integrin αIIbβ3 activation and platelet aggregation. Although there was no difference in Ca2+ rise, platelet granule secretion and thromboxane A2 (TxA2) generation were significantly attenuated in ASK1-/- platelets. The defective granule secretion observed in ASK1-/- platelets was a consequence of impaired TxA2 generation. Biochemical studies showed that platelet agonists failed to activate p38 MAPK in ASK1-/- platelets. On the contrary, activation of c-Jun N-terminal kinases and extracellular signal-regulated kinase 1/2 MAPKs was augmented in ASK1-/- platelets. The defect in p38 MAPK results in failed phosphorylation of cPLA2 in ASK1-/- platelets and impaired platelet aggregate formation under flow. The absence of ASK1 renders mice defective in hemostasis as assessed by prolonged tail-bleeding times. Deletion of ASK1 also reduces thrombosis as assessed by delayed vessel occlusion of carotid artery after FeCl3-induced injury and protects against collagen/epinephrine-induced pulmonary thromboembolism. These results suggest that the platelet ASK1 plays an important role in regulation of hemostasis and thrombosis.
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pleiotropic properties of ASK1
Biochimica et Biophysica Acta, 2017Co-Authors: Chihiro Sakauchi, Hidenori Ichijo, Hiroaki Wakatsuki, Kazuki HattoriAbstract:Abstract Background Apoptosis signal-regulating kinase 1 (ASK1), also known as mitogen-activated protein kinase kinase kinase 5 (MAP3K5), has the potential to induce cellular apoptosis under various physiological conditions. It has long been suggested that ASK1 is highly sensitive to oxidative stress and contributes substantially to apoptosis. However, recent studies have indicated that ASK1 has pleiotropic roles in living organisms through other mechanisms in addition to apoptosis. Scope of the review This review describes the physiological functions of ASK1 in living organisms, focusing on the regulatory mechanisms of ASK1 activity and its importance in the pathogenesis of various diseases. We also highlight recent works published within the past few years. Major conclusions ASK1 forms a high-molecular-mass complex within the cell, designated as the ASK1 signalosome. Soon after the discovery of ASK1, several regulatory components of the ASK1 signalosome have been revealed, including thioredoxin (Trx), tumor-necrosis factor α receptor-associated factors (TRAFs) and 14‐3-3s. In parallel with the precise analyses unveiling the molecular basis of ASK1 regulation, the physiological or pathophysiological significance of ASK1 in diverse organs has been elucidated. In addition to the generation of global knockout mice or tissue-specific knockout mice, ASK1-specific inhibitors have illuminated the biological roles of ASK1. General significance The multi-faceted features of the function of ASK1 have been discovered over the past two decades, revealing that ASK1 is a crucial molecule for maintaining cellular homeostasis, especially under conditions of stress. Based on the results that ASK1 deficiency provides beneficial effects for several diseases, modulating ASK1 activity is a promising method to ameliorate a subset of diseases.
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inhibition of apoptosis signal regulating kinase 1 enhances endochondral bone formation by increasing chondrocyte survival
Cell Death and Disease, 2014Co-Authors: Gregory J Eaton, Atsushi Matsuzawa, Hidenori Ichijo, Qianshi Zhang, Carol Diallo, Marla J Steinbeck, Theresa A FreemanAbstract:Endochondral ossification is the result of chondrocyte differentiation, hypertrophy, death and replacement by bone. The careful timing and progression of this process is important for normal skeletal bone growth and development, as well as fracture repair. Apoptosis Signal-Regulating Kinase 1 (ASK1) is a mitogen-activated protein kinase (MAPK), which is activated by reactive oxygen species and other cellular stress events. Activation of ASK1 initiates a signaling cascade known to regulate diverse cellular events including cytokine and growth factor signaling, cell cycle regulation, cellular differentiation, hypertrophy, survival and apoptosis. ASK1 is highly expressed in hypertrophic chondrocytes, but the role of ASK1 in skeletal tissues has not been investigated. Herein, we report that ASK1 knockout (KO) mice display alterations in normal growth plate morphology, which include a shorter proliferative zone and a lengthened hypertrophic zone. These changes in growth plate dynamics result in accelerated long bone mineralization and an increased formation of trabecular bone, which can be attributed to an increased resistance of terminally differentiated chondrocytes to undergo cell death. Interestingly, under normal cell culture conditions, mouse embryonic fibroblasts (MEFs) derived from ASK1 KO mice show no differences in either MAPK signaling or osteogenic or chondrogenic differentiation when compared with wild-type (WT) MEFs. However, when cultured with stress activators, H2O2 or staurosporine, the KO cells show enhanced survival, an associated decrease in the activation of proteins involved in death signaling pathways and a reduction in markers of terminal differentiation. Furthermore, in both WT mice treated with the ASK1 inhibitor, NQDI-1, and ASK1 KO mice endochondral bone formation was increased in an ectopic ossification model. These findings highlight a previously unrealized role for ASK1 in regulating endochondral bone formation. Inhibition of ASK1 has clinical potential to treat fractures or to slow osteoarthritic progression by enhancing chondrocyte survival and slowing hypertrophy.
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inhibition of ASK1 p38 pathway prevents neural cell death following optic nerve injury
Cell Death & Differentiation, 2013Co-Authors: Takashi Katome, Hidenori Ichijo, Chikako Harada, Xiaoli Guo, Atsuko Kimura, Kazuhiko Namekata, Kentaro Semba, Daiji Kittaka, Kazuto Kawamura, Yoshinori MitamuraAbstract:Optic nerve injury (ONI) induces retinal ganglion cell (RGC) death and optic nerve atrophy that lead to visual loss. Apoptosis signal-regulating kinase 1 (ASK1) is an evolutionarily conserved mitogen-activated protein kinase (MAPK) kinase kinase and has an important role in stress-induced RGC apoptosis. In this study, we found that ONI-induced p38 activation and RGC loss were suppressed in ASK1-deficient mice. Sequential in vivo retinal imaging revealed that post-ONI treatment with a p38 inhibitor into the eyeball was effective for RGC protection. ONI-induced monocyte chemotactic protein-1 production in RGCs and microglial accumulation around RGCs were suppressed in ASK1-deficient mice. In addition, the productions of tumor necrosis factor and inducible nitric oxide synthase in microglia were decreased when the ASK1-p38 pathway was blocked. These results suggest that ASK1 activation in both neural and glial cells is involved in neural cell death, and that pharmacological interruption of ASK1-p38 pathways could be beneficial in the treatment of ONI.
Kohsuke Takeda - One of the best experts on this subject based on the ideXlab platform.
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ASK1 facilitates tumor metastasis through phosphorylation of an adp receptor p2y12 in platelets
Cell Death & Differentiation, 2017Co-Authors: Miki Kamiyama, Kohei Miyazono, Toshiaki Shirai, Shogo Tamura, Katsue Suzukiinoue, Shogo Ehata, Kei Takahashi, Yoshihiro Hayakawa, Takehiro Sato, Kohsuke TakedaAbstract:Tumor metastasis is the major cause of deaths in cancer patients and is modulated by intertwined stress-responsive signaling cascades. Here we demonstrate that deletion of stress-responsive apoptosis signal-regulating kinase 1 (ASK1) in platelets results in unstable hemostasis and drastic attenuation of tumor lung metastasis, both of which are attributable to platelet dysfunction. Platelet-specific deletion of ASK1 in mice leads to defects in ADP-dependent platelet aggregation, unstable hemostasis and subsequent attenuation of tumor metastasis. We also revealed that activating phosphorylation of Akt is attenuated in ASK1-deficient platelets, contrary to the previous reports suggesting that Akt is negatively regulated by ASK1. Mechanistically, ASK1-JNK/p38 axis phosphorylates an ADP receptor P2Y12 at Thr345, which is required for the ADP-dependent sustained Akt activity that is vital to normal platelet functions. Our findings offer insight into positive regulation of Akt signaling through P2Y12 phosphorylation as well as MAPK signaling in platelets by ASK1 and suggest that ASK1-JNK/p38 axis provides a new therapeutic opportunity for tumor metastasis.
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the ask family kinases differentially mediate induction of type i interferon and apoptosis during the antiviral response
Science Signaling, 2015Co-Authors: Tomohiko Okazaki, Kohsuke Takeda, Maiko Higuchi, Kiyoko Iwatsukihorimoto, Maki Kiso, Makoto Miyagishi, Hideyuki Yanai, Atsushi Kato, Mitsutoshi Yoneyama, Takashi FujitaAbstract:Viral infection activates host defense mechanisms, including the production of type I interferon (IFN) and the apoptosis of infected cells. We investigated whether these two antiviral responses were differentially regulated in infected cells. We showed that the mitogen-activated protein kinase (MAPK) kinase kinase (MAPKKK) apoptosis signal-regulating kinase 1 (ASK1) was activated in cells by the synthetic double-stranded RNA analog polyinosinic:polycytidylic acid [poly(I:C)] and by RNA viruses, and that ASK1 played an essential role in both the induction of the gene encoding IFN-β (IFNB) and apoptotic cell death. In contrast, we found that the MAPKKK ASK2, a modulator of ASK1 signaling, was essential for ASK1-dependent apoptosis, but not for inducing IFNB expression. Furthermore, genetic deletion of either ASK1 or ASK2 in mice promoted the replication of influenza A virus in the lung. These results indicated that ASK1 and ASK2 are components of the antiviral defense mechanism and suggested that ASK2 acts as a key modulator that promotes apoptosis rather than the type I IFN response. Because ASK2 is selectively present in epithelium-rich tissues, such as the lung, ASK2-dependent apoptosis may contribute to an antiviral defense in tissues with a rapid repair rate in which cells could be readily replaced.
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apoptosis signal regulating kinase 1 inhibitor as a potent therapeutic drug for the treatment of gastric cancer
Cancer Science, 2012Co-Authors: Yoku Hayakawa, Kohsuke Takeda, Yoshihiro Hirata, Hayato Nakagawa, Hiroto Kinoshita, Wachiko Nakata, Ryota Takahashi, Kosuke Sakitani, Hidenori IchijoAbstract:Aside from the human epidermal growth factor receptor-2 (HER2)-targeting agent trastuzumab, molecular targeting therapy for gastric cancer (GC) has not been established. We previously reported that apoptosis signal-regulating kinase-1 (ASK1) was upregulated in human GC and that overexpression of ASK1 promoted GC cell proliferation. Here, we investigated the effect of ASK1 inhibitor K811 on GC cells. K811 efficiently prevented cell proliferation in cell lines with high ASK1 expression and in HER2-overexpressing GC cells. Treatment with K811 reduced sizes of xenograft tumors by downregulating proliferation markers. These results indicate that ASK1 inhibition prevents GC cell growth in vitro and in vivo, suggesting that ASK1 inhibitors can be potent therapeutic drugs for GC.
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The Kelch Repeat Protein KLHDC10 Regulates Oxidative Stress-Induced ASK1 Activation by Suppressing PP5
Molecular Cell, 2012Co-Authors: Yusuke Sekine, Kohsuke Takeda, Ryo Hatanaka, Takeshi Watanabe, Naoki Sono, Shun-ichiro Iemura, Tohru Natsume, Erina Kuranaga, Masayuki Miura, Hidenori IchijoAbstract:Reactive oxygen species (ROS)-induced activation of Apoptosis signal-regulating kinase 1 (ASK1) plays crucial roles in oxidative stress-mediated cell death through the activation of the JNK and p38 MAPK pathways. However, the regulatory mechanism of ASK1 in the oxidative stress response remains to be elucidated. Here, we identified the kelch repeat protein, Slim, as an activator of ASK1 through a Drosophila misexpression screen. We also performed a proteomics screen and revealed that Kelch domain containing 10 (KLHDC10), a mammalian ortholog of Slim, interacted with Protein phosphatase 5 (PP5), which has been shown to inactivate ASK1 in response to ROS. KLHDC10 bound to the phosphatase domain of PP5 and suppressed its phosphatase activity. Moreover, KLHDC10 was required for H(2)O(2)-induced sustained activation of ASK1 and cell death in Neuro2A cells. These findings suggest that Slim/KLHDC10 is an activator of ASK1, contributing to oxidative stress-induced cell death through the suppression of PP5.
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ubiquitin like sequence in ASK1 plays critical roles in the recognition and stabilization by usp9x and oxidative stress induced cell death
Molecular Cell, 2009Co-Authors: Hiroaki Nagai, Takuya Noguchi, Atsushi Matsuzawa, Kohsuke Takeda, Kazumi Katagiri, Kengo Homma, Hidenori IchijoAbstract:Ubiquitination is an important posttranslational modification that regulates various cellular processes, including signal transduction. However, physiological roles of ubiquitination in the regulation of MAPK pathways are poorly understood. Here, we identified the deubiquitinating enzyme USP9X as a binding partner of ASK1 that mediates oxidative stress-induced cell death through activation of the JNK and p38 MAPK pathways. In the recognition of ubiquitin by deubiquitinating enzymes, the importance of a tandem glycine-glycine sequence in the ubiquitin C terminus has been suggested. Interestingly, ASK1 contains six amino acids identical to the ubiquitin C terminus (LRLRGG), and the GG sequence of ASK1 was required for the USP9X-ASK1 interaction. We also found that USP9X interacted with oxidative stress-activated ASK1 and prevented it from undergoing ubiquitin-dependent degradation. In USP9X-deficient cells, oxidative stress-induced JNK activation and subsequent cell death were reduced. These results demonstrate that USP9X-dependent stabilization of activated ASK1 plays a crucial role in oxidative stress-induced cell death.
Atsushi Matsuzawa - One of the best experts on this subject based on the ideXlab platform.
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inhibition of apoptosis signal regulating kinase 1 enhances endochondral bone formation by increasing chondrocyte survival
Cell Death and Disease, 2014Co-Authors: Gregory J Eaton, Atsushi Matsuzawa, Hidenori Ichijo, Qianshi Zhang, Carol Diallo, Marla J Steinbeck, Theresa A FreemanAbstract:Endochondral ossification is the result of chondrocyte differentiation, hypertrophy, death and replacement by bone. The careful timing and progression of this process is important for normal skeletal bone growth and development, as well as fracture repair. Apoptosis Signal-Regulating Kinase 1 (ASK1) is a mitogen-activated protein kinase (MAPK), which is activated by reactive oxygen species and other cellular stress events. Activation of ASK1 initiates a signaling cascade known to regulate diverse cellular events including cytokine and growth factor signaling, cell cycle regulation, cellular differentiation, hypertrophy, survival and apoptosis. ASK1 is highly expressed in hypertrophic chondrocytes, but the role of ASK1 in skeletal tissues has not been investigated. Herein, we report that ASK1 knockout (KO) mice display alterations in normal growth plate morphology, which include a shorter proliferative zone and a lengthened hypertrophic zone. These changes in growth plate dynamics result in accelerated long bone mineralization and an increased formation of trabecular bone, which can be attributed to an increased resistance of terminally differentiated chondrocytes to undergo cell death. Interestingly, under normal cell culture conditions, mouse embryonic fibroblasts (MEFs) derived from ASK1 KO mice show no differences in either MAPK signaling or osteogenic or chondrogenic differentiation when compared with wild-type (WT) MEFs. However, when cultured with stress activators, H2O2 or staurosporine, the KO cells show enhanced survival, an associated decrease in the activation of proteins involved in death signaling pathways and a reduction in markers of terminal differentiation. Furthermore, in both WT mice treated with the ASK1 inhibitor, NQDI-1, and ASK1 KO mice endochondral bone formation was increased in an ectopic ossification model. These findings highlight a previously unrealized role for ASK1 in regulating endochondral bone formation. Inhibition of ASK1 has clinical potential to treat fractures or to slow osteoarthritic progression by enhancing chondrocyte survival and slowing hypertrophy.
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Oxidative Stress-Induced Diseases via the ASK1 Signaling Pathway
International journal of cell biology, 2012Co-Authors: Mayumi Soga, Atsushi Matsuzawa, Hidenori IchijoAbstract:Apoptosis signal-regulating kinase 1 (ASK1) is a mitogen-activated protein kinase (MAPK) kinase kinase that activates the downstream MAPKs, c-Jun N-terminal kinase (JNK) and p38. ASK1 is activated by various types of stress, such as oxidative stress, endoplasmic reticulum stress, and infection, and regulates various cellular functions. Recently, it has been reported that ASK1 is associated with various diseases induced by oxidative stress. In this review, we introduce recent findings of the regulatory mechanisms of ASK1 and the oxidative stress-induced diseases mediated by the ASK1 signaling pathway.
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regulation of the severity of neuroinflammation and demyelination by tlr ASK1 p38 pathway
Embo Molecular Medicine, 2010Co-Authors: Xiaoli Guo, Atsushi Matsuzawa, Chikako Harada, Kazuhiko Namekata, Montserrat Camps, Dominique Swinnen, Catherine Jorandlebrun, Mathilde Muzerelle, Pierre Alain Vitte, Thomas RuckleAbstract:Apoptosis signal-regulating kinase 1 (ASK1) is an evolutionarily conserved mitogen-activated protein kinase (MAPK) kinase kinase which plays important roles in stress and immune responses. Here, we show that ASK1 deficiency attenuates neuroinflammation in experimental autoimmune encephalomyelitis (EAE), without affecting the proliferation capability of T cells. Moreover, we found that EAE upregulates expression of Toll-like receptors (TLRs) in activated astrocytes and microglia, and that TLRs can synergize with ASK1-p38 MAPK signalling in the release of key chemokines from astrocytes. Consequently, oral treatment with a specific small molecular weight inhibitor of ASK1 suppressed EAE-induced autoimmune inflammation in both spinal cords and optic nerves. These results suggest that the TLR-ASK1-p38 pathway in glial cells may serve as a valid therapeutic target for autoimmune demyelinating disorders including multiple sclerosis.
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ubiquitin like sequence in ASK1 plays critical roles in the recognition and stabilization by usp9x and oxidative stress induced cell death
Molecular Cell, 2009Co-Authors: Hiroaki Nagai, Takuya Noguchi, Atsushi Matsuzawa, Kohsuke Takeda, Kazumi Katagiri, Kengo Homma, Hidenori IchijoAbstract:Ubiquitination is an important posttranslational modification that regulates various cellular processes, including signal transduction. However, physiological roles of ubiquitination in the regulation of MAPK pathways are poorly understood. Here, we identified the deubiquitinating enzyme USP9X as a binding partner of ASK1 that mediates oxidative stress-induced cell death through activation of the JNK and p38 MAPK pathways. In the recognition of ubiquitin by deubiquitinating enzymes, the importance of a tandem glycine-glycine sequence in the ubiquitin C terminus has been suggested. Interestingly, ASK1 contains six amino acids identical to the ubiquitin C terminus (LRLRGG), and the GG sequence of ASK1 was required for the USP9X-ASK1 interaction. We also found that USP9X interacted with oxidative stress-activated ASK1 and prevented it from undergoing ubiquitin-dependent degradation. In USP9X-deficient cells, oxidative stress-induced JNK activation and subsequent cell death were reduced. These results demonstrate that USP9X-dependent stabilization of activated ASK1 plays a crucial role in oxidative stress-induced cell death.
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thioredoxin and traf family proteins regulate reactive oxygen species dependent activation of ASK1 through reciprocal modulation of the n terminal homophilic interaction of ASK1
Molecular and Cellular Biology, 2007Co-Authors: Go Fujino, Takuya Noguchi, Atsushi Matsuzawa, Kohsuke Takeda, Masao Saitoh, Shota Yamauchi, Hidenori IchijoAbstract:Apoptosis signal-regulating kinase 1 (ASK1), a member of the mitogen-activated protein kinase kinase kinase family, plays pivotal roles in reactive oxygen species (ROS)-induced cellular responses. In resting cells, endogenous ASK1 constitutively forms a homo-oligomerized but still inactive high-molecular-mass complex including thioredoxin (Trx), which we designated the ASK1 signalosome. Upon ROS stimulation, the ASK1 signalosome unbinds from Trx and forms a fully activated higher-molecular-mass complex, in part by recruitment of tumor necrosis factor receptor-associated factor 2 (TRAF2) and TRAF6. However, the precise mechanisms by which Trx inhibits and TRAF2 and TRAF6 activate ASK1 have not been elucidated fully. Here we demonstrate that the N-terminal homophilic interaction of ASK1 through the N-terminal coiled-coil domain is required for ROS-dependent activation of ASK1. Trx inhibited this interaction of ASK1, which was, however, enhanced by expression of TRAF2 or TRAF6 or by treatment of cells with H2O2. Furthermore, the H2O2induced interaction was reduced by double knockdown of TRAF2 and TRAF6. These findings demonstrate that Trx, TRAF2, and TRAF6 regulate ASK1 activity by modulating N-terminal homophilic interaction of ASK1.
Hideki Nishitoh - One of the best experts on this subject based on the ideXlab platform.
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ASK1 and ask2 differentially regulate the counteracting roles of apoptosis and inflammation in tumorigenesis
The EMBO Journal, 2009Co-Authors: Takayuki Iriyama, Takuya Noguchi, Kohsuke Takeda, Isao Naguro, Tsuyoshi Umeda, Yoshifumi Morimoto, Hiromi Nakamura, Takumi Kuroiwa, Junya Mizukami, Hideki NishitohAbstract:Apoptosis and inflammation generally exert opposite effects on tumorigenesis: apoptosis serves as a barrier to tumour initiation, whereas inflammation promotes tumorigenesis. Although both events are induced by various common stressors, relatively little is known about the stress-induced signalling pathways regulating these events in tumorigenesis. Here, we show that stress-activated MAP3Ks, ASK1 and ASK2, which are involved in cellular responses to various stressors such as reactive oxygen species, differentially regulate the initiation and promotion of tumorigenesis. ASK2 in cooperation with ASK1 functioned as a tumour suppressor by exerting proapoptotic activity in epithelial cells, which was consistent with the reduction in ASK2 expression in human cancer cells and tissues. In contrast, ASK1-dependent cytokine production in inflammatory cells promoted tumorigenesis. Our findings suggest that ASK1 and ASK2 are critically involved in tumorigenesis by differentially regulating apoptosis and inflammation.
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ROS-dependent activation of the TRAF6-ASK1-p38 pathway is selectively required for TLR4-mediated innate immunity
Nature Immunology, 2005Co-Authors: Atsushi Matsuzawa, Kaoru Saegusa, Chiharu Sadamitsu, Takuya Noguchi, Shigenori Nagai, Kohsuke Takeda, Shigeo Koyasu, Hideki Nishitoh, Kunihiro Matsumoto, Hidenori IchijoAbstract:Apoptosis signal–regulating kinase 1 (ASK1) is an evolutionarily conserved mitogen-activated protein 3-kinase that activates both Jnk and p38 mitogen-activated protein kinases. Here we used ASK1-deficient mice to show that ASK1 was selectively required for lipopolysaccharide-induced activation of p38 but not of Jnk or the transcription factor NF-κB. ASK1 was required for the induction of proinflammatory cytokines dependent on Toll-like receptor 4 (TLR4) but not TLR2 or other TLRs. Consistent with this, ASK1-deficient mice were resistant to lipopolysaccharide-induced septic shock. Lipopolysaccharide induced the production of intracellular reactive oxygen species, which was required for the formation of a complex of the adaptor molecule TRAF6 and ASK1 and subsequent activation of the ASK1-p38 pathway. Our data demonstrate that the reactive oxygen species–dependent TRAF6-ASK1-p38 axis is crucial for TLR4-mediated mammalian innate immunity.
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amyloid beta induces neuronal cell death through ros mediated ASK1 activation
Cell Death & Differentiation, 2005Co-Authors: Chiharu Sadamitsu, Atsushi Matsuzawa, Kohsuke Takeda, Hideki Nishitoh, Hisae Kadowaki, Fumihiko Urano, Hiroshi Masutani, Junji YodoiAbstract:Amyloid β (Aβ) is a main component of senile plaques in Alzheimer's disease and induces neuronal cell death. Reactive oxygen species (ROS), nitric oxide and endoplasmic reticulum (ER) stress have been implicated in Aβ-induced neurotoxicity. We have reported that apoptosis signal-regulating kinase 1 (ASK1) is required for ROS- and ER stress-induced JNK activation and apoptosis. Here we show the involvement of ASK1 in Aβ-induced neuronal cell death. Aβ activated ASK1 mainly through production of ROS but not through ER stress in cultured neuronal cells. Importantly, ASK1−/− neurons were defective in Aβ-induced JNK activation and cell death. These results indicate that ROS-mediated ASK1 activation is a key mechanism for Aβ-induced neurotoxicity, which plays a central role in Alzheimer's disease.
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Amyloid β induces neuronal cell death through ROS-mediated ASK1 activation
Cell Death & Differentiation, 2005Co-Authors: Hisae Kadowaki, Chiharu Sadamitsu, Hideki Nishitoh, Fumihiko Urano, Hiroshi Masutani, Junji Yodoi, A Matsuzawa, K Takeda, Y Urano, T NaganoAbstract:Amyloid β (A β ) is a main component of senile plaques in Alzheimer's disease and induces neuronal cell death. Reactive oxygen species (ROS), nitric oxide and endoplasmic reticulum (ER) stress have been implicated in A β -induced neurotoxicity. We have reported that apoptosis signal-regulating kinase 1 (ASK1) is required for ROS- and ER stress-induced JNK activation and apoptosis. Here we show the involvement of ASK1 in A β -induced neuronal cell death. A β activated ASK1 mainly through production of ROS but not through ER stress in cultured neuronal cells. Importantly, ASK1 ^−/− neurons were defective in A β -induced JNK activation and cell death. These results indicate that ROS-mediated ASK1 activation is a key mechanism for A β -induced neurotoxicity, which plays a central role in Alzheimer's disease.
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involvement of ASK1 in ca2 induced p38 map kinase activation
EMBO Reports, 2004Co-Authors: Kohsuke Takeda, Atsushi Matsuzawa, Hideki Nishitoh, Kunihiro Matsumoto, Kei Tobiume, Satoshi Kishida, Jun Ninomiyatsuji, Hidenori IchijoAbstract:The mammalian mitogen-activated protein (MAP) kinase kinase kinase apoptosis signal-regulating kinase 1 (ASK1) is a pivotal component in cytokine- and stress-induced apoptosis. It also regulates cell differentiation and survival through p38 MAP kinase activation. Here we show that Ca2+ signalling regulates the ASK1–p38 MAP kinase cascade. Ca2+ influx evoked by membrane depolarization in primary neurons and synaptosomes induced activation of p38, which was impaired in those derived from ASK1-deficient mice. Ca2+/calmodulin-dependent protein kinase type II (CaMKII) activated ASK1 by phosphorylation. Moreover, p38 activation induced by the expression of constitutively active CaMKII required endogenous ASK1. Thus, ASK1 is a critical intermediate of Ca2+ signalling between CaMKII and p38 MAP kinase.
Wang Min - One of the best experts on this subject based on the ideXlab platform.
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structural and functional characterization of the human protein kinase ASK1
Structure, 2007Co-Authors: Gabor Bunkoczi, Wang Min, Haifeng Zhang, E Salah, P Filippakopoulos, O Fedorov, Susanne Muller, Frank Sobott, Sirlester A Parker, Benjamin E TurkAbstract:Apoptosis signal-regulating kinase 1 (ASK1) plays an essential role in stress and immune response and has been linked to the development of several diseases. Here, we present the structure of the human ASK1 catalytic domain in complex with staurosporine. Analytical ultracentrifugation (AUC) and crystallographic analysis showed that ASK1 forms a tight dimer (K(d) approximately 0.2 microM) interacting in a head-to-tail fashion. We found that the ASK1 phosphorylation motifs differ from known ASK1 phosphorylation sites but correspond well to autophosphorylation sites identified by mass spectrometry. Reporter gene assays showed that all three identified in vitro autophosphorylation sites (Thr813, Thr838, Thr842) regulate ASK1 signaling, but site-directed mutants showed catalytic activities similar to wild-type ASK1, suggesting a regulatory mechanism independent of ASK1 kinase activity. The determined high-resolution structure of ASK1 and identified ATP mimetic inhibitors will provide a first starting point for the further development of selective inhibitors.
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socs1 inhibits tumor necrosis factor induced activation of ASK1 jnk inflammatory signaling by mediating ASK1 degradation
Journal of Biological Chemistry, 2006Co-Authors: Wei Zhang, Rong Zhang, Haifeng Zhang, Wang MinAbstract:We have previously shown that ASK1 undergoes ubiquitination and degradation in resting endothelial cells (EC) and that proinflammatory cytokine tumor necrosis factor (TNF) induces deubiquitination and stabilization, leading to ASK1 activation. However, the mechanism for the regulation of ASK1 stability is not known. In the present study, we have shown that SOCS1, a member of suppressor of cytokine signaling, induces ASK1 degradation. SOCS1 was constitutively expressed in EC and formed a labile complex with ASK1 that can be stabilized by proteasomal inhibitors. The phosphotyrosine-binding SH2 domain of SOCS1 was critical for its association with ASK1. Thus a SOCS1 mutant defective in phosphotyrosine binding failed to bind to and induce ASK1 degradation. Phosphotyrosine of ASK1 was induced in response to growth factors, and TNF induced dephosphorylation and dissociation of ASK1 from SOCS1. ASK1 with a mutation at Tyr-718 diminished the binding to SOCS1, suggesting that the phosphotyrosine-718 of ASK1 is critical for SOCS1 binding. Moreover, ASK1 expression and activity were up-regulated in SOCS1-deficient mice and derived EC, resulting in enhanced TNF-induced activation of JNK, expression of proinflammatory molecules, and apoptotic responses. We concluded that SOCS1 functions as a negative regulator in TNF-induced inflammation in EC, in part, by inducing ASK1 degradation.
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hsp90 akt phosphorylates ASK1 and inhibits ASK1 mediated apoptosis
Oncogene, 2005Co-Authors: Rong Zhang, Lanfang Bai, Dianhong Luo, Robert Q Miao, William C Sessa, Wang MinAbstract:Hsp90 client protein Akt has been shown to inhibit cell apoptosis in part by inhibiting proapoptotic kinase ASK1 (apoptosis signal-regulating kinase 1) activity. In the present study, we show that Hsp90 inhibits hydrogen peroxide (H2O2)-induced ASK1–p38 activation in endothelial cells (EC). The inhibitory effect of Hsp90 on ASK1–p38 activities is diminished when the Akt phosphorylation site on ASK1 (pSer83) is absent or when Akt is genetically deleted in cells, suggesting that Hsp90 and Akt function together to inhibit ASK1–p38 signaling. Thus, inhibition of Hsp90 by 17-allyamino-17-demethoxygeldanamycin (17-AAG) or phosphatidylinositol 3-kinase (PI3K) LY294002 induced and synergized ASK1 activation and ASK1-mediated EC apoptosis. Furthermore, we show that in resting EC Hsp90, Akt and ASK1 form a ternary complex in which both Akt and ASK1 bind to the middle domain of Hsp90, suggesting that Hsp90 may hold Akt and ASK1 in close proximity. The N-terminal domain of ASK1 containing the Akt phosphorylation site (pSer83) associates with Akt in resting state. However, Akt is released from the N-terminal domain concomitant with binding to the C-terminal domain of ASK1 in response to ASK1 activator H2O2, inhibitor of Hsp90 17-AAG and Akt inhibitor LY294002, leading to a more stable Hsp90-Akt–ASK1 complex. We conclude that Hsp90–Akt forms a complex with ASK1 and protect EC from stress-induced apoptosis.
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tumor necrosis factor α induced desumoylation and cytoplasmic translocation of homeodomain interacting protein kinase 1 are critical for apoptosis signal regulating kinase 1 jnk p38 activation
Journal of Biological Chemistry, 2005Co-Authors: Rong Zhang, Dianhong Luo, Sangjoon Park, Qian Wang, Yongsok Kim, Wang MinAbstract:The apoptosis signal-regulating kinase 1 (ASK1)-JNK/p38 signaling pathway is pivotal component in cell apoptosis and can be activated by a variety of death stimuli including tumor necrosis factor (TNF) alpha and oxidative stress (reactive oxygen species). However, the mechanism for ASK1 activation is not fully understood. We have recently identified ASK1-interacting protein (AIP1) as novel signal transducer in TNFalpha-induced ASK1 activation by facilitating dissociation of ASK1 from its inhibitor 14-3-3. In the present study, we employed yeast two-hybrid system using the N-terminal domain of AIP1 as bait and identified homeodomain-interacting protein kinase 1 (HIPK1) as an AIP1-associated protein. Interestingly, we showed that TNFalpha induced HIPK1 desumoylation concomitant with a translocation from nucleus to cytoplasm at 15 min followed by a return to nucleus by 60 min. The kinetics of HIPK1 translocation correlates with those of stress-induced ASK1-JNK/P38 activation. A specific JNK inhibitor blocked the reverse but not the initial translocation of HIPK1, suggesting that the initial translocation is an upstream event of ASK1-JNK/p38 signaling and JNK activation regulates the reverse translocation as a feedback mechanism. Consistently, expression of HIPK1 increased, whereas expression of a kinase-inactive form (HIPK1-D315N) or small interference RNA of HIPK1 decreased stress-induced ASK1-JNK/P38 activation without effects on IKK-NF-kappaB signaling. Moreover, a sumoylation-defective mutant of HIPK1 (KR5) localizes to the cytoplasm and is constitutively active in ASK1-JNK/P38 activation. Furthermore, HIPK1-KR5 induces dissociation of ASK1 from its inhibitors 14-3-3 and thioredoxin and synergizes with AIP1 to induce ASK1 activation. Our study suggests that TNFalpha-induced desumoylation and cytoplasmic translocation of HIPK1 are critical in TNFalpha-induced ASK1-JNK/p38 activation.
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thioredoxin 2 inhibits mitochondria located ASK1 mediated apoptosis in a jnk independent manner
Circulation Research, 2004Co-Authors: Rong Zhang, Rafia S Allamki, Lanfang Bai, Jeffrey W Streb, Joseph M Miano, John Bradley, Wang MinAbstract:Apoptosis signal-regulating kinase 1 (ASK1) mediates cytokines and oxidative stress (ROS)-induced apoptosis in a mitochondria-dependent pathway. However, the underlying mechanism has not been defined. In this study, we show that ASK1 is localized in both cytoplasm and mitochondria of endothelial cells (ECs) where it binds to cytosolic (Trx1) and mitochondrial thioredoxin (Trx2), respectively. Cys-250 and Cys-30 in the N-terminal domain of ASK1 are critical for binding of Trx1 and Trx2, respectively. Mutation of ASK1 at C250 enhanced ASK1-induced JNK activation and apoptosis, whereas mutation of ASK1 at C30 specifically increased ASK1-induced apoptosis without effects on JNK activation. We further show that a JNK-specific inhibitor SP600125 completely blocks TNF induced JNK activation, Bid cleavage, and Bax mitochondrial translocation, but only partially inhibits cytochrome c release and EC death, suggesting that TNF induces both JNK-dependent and JNK-independent apoptotic pathways in EC. Mitochondria-specific expression of a constitutively active ASK1 strongly induces EC apoptosis without JNK activation, Bid cleavage, and Bax mitochondrial translocation. These data suggest that mitochondrial ASK1 mediates a JNK-independent apoptotic pathway induced by TNF. To determine the role of Trx2 in regulation of mitochondrial ASK1 activity, we show that overexpression of Trx2 inhibits ASK1-induced apoptosis without effects on ASK1-induced JNK activation. Moreover, specific knockdown of Trx2 in EC increases TNF/ASK1-induced cytochrome c release and cell death without increase in JNK activation, Bid cleavage, and Bax translocation. Our data suggest that ASK1 in cytoplasm and mitochondria mediate distinct apoptotic pathways induced by TNF, and Trx1 and Trx2 cooperatively inhibit ASK1 activities.
