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Stouffer MA, Khalaf-Nazzal R, Cifuentes-Diaz C, Albertini G, Bandet E, Grannec G, Lavilla V, Deleuze JF, Olaso R, Nosten-Bertrand M, Francis F. Doublecortin mutation leads to persistent defects in the Golgi apparatus and mitochondria in adult hippocampal pyramidal cells. Neurobiol Dis 2022; 168:105702. [PMID: 35339680 DOI: 10.1016/j.nbd.2022.105702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 02/08/2022] [Accepted: 03/17/2022] [Indexed: 11/08/2022] Open
Abstract
Human doublecortin (DCX) mutations are associated with severe brain malformations leading to aberrant neuron positioning (heterotopia), intellectual disability and epilepsy. DCX is a microtubule-associated protein which plays a key role during neurodevelopment in neuronal migration and differentiation. Dcx knockout (KO) mice show disorganized hippocampal pyramidal neurons. The CA2/CA3 pyramidal cell layer is present as two abnormal layers and disorganized CA3 KO pyramidal neurons are also more excitable than wild-type (WT) cells. To further identify abnormalities, we characterized Dcx KO hippocampal neurons at subcellular, molecular and ultrastructural levels. Severe defects were observed in mitochondria, affecting number and distribution. Also, the Golgi apparatus was visibly abnormal, increased in volume and abnormally organized. Transcriptome analyses from laser microdissected hippocampal tissue at postnatal day 60 (P60) highlighted organelle abnormalities. Ultrastructural studies of CA3 cells performed in P60 (young adult) and > 9 months (mature) tissue showed that organelle defects are persistent throughout life. Locomotor activity and fear memory of young and mature adults were also abnormal: Dcx KO mice consistently performed less well than WT littermates, with defects becoming more severe with age. Thus, we show that disruption of a neurodevelopmentally-regulated gene can lead to permanent organelle anomalies contributing to abnormal adult behavior.
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Affiliation(s)
- M A Stouffer
- INSERM UMR-S 1270, Paris 75005, France; Sorbonne Université, Université Pierre et Marie Curie, Paris 75005, France; Institut du Fer à Moulin, Paris 75005, France
| | - R Khalaf-Nazzal
- INSERM UMR-S 1270, Paris 75005, France; Sorbonne Université, Université Pierre et Marie Curie, Paris 75005, France; Institut du Fer à Moulin, Paris 75005, France
| | - C Cifuentes-Diaz
- INSERM UMR-S 1270, Paris 75005, France; Sorbonne Université, Université Pierre et Marie Curie, Paris 75005, France; Institut du Fer à Moulin, Paris 75005, France
| | - G Albertini
- INSERM UMR-S 1270, Paris 75005, France; Sorbonne Université, Université Pierre et Marie Curie, Paris 75005, France; Institut du Fer à Moulin, Paris 75005, France
| | - E Bandet
- INSERM UMR-S 1270, Paris 75005, France; Sorbonne Université, Université Pierre et Marie Curie, Paris 75005, France; Institut du Fer à Moulin, Paris 75005, France
| | - G Grannec
- INSERM UMR-S 1270, Paris 75005, France; Sorbonne Université, Université Pierre et Marie Curie, Paris 75005, France; Institut du Fer à Moulin, Paris 75005, France
| | - V Lavilla
- Université Paris-Saclay, CEA, Centre National de Recherche en Génomique Humaine (CNRGH), 91057 Evry, France
| | - J-F Deleuze
- Université Paris-Saclay, CEA, Centre National de Recherche en Génomique Humaine (CNRGH), 91057 Evry, France
| | - R Olaso
- Université Paris-Saclay, CEA, Centre National de Recherche en Génomique Humaine (CNRGH), 91057 Evry, France
| | - M Nosten-Bertrand
- INSERM UMR-S 1270, Paris 75005, France; Sorbonne Université, Université Pierre et Marie Curie, Paris 75005, France; Institut du Fer à Moulin, Paris 75005, France
| | - F Francis
- INSERM UMR-S 1270, Paris 75005, France; Sorbonne Université, Université Pierre et Marie Curie, Paris 75005, France; Institut du Fer à Moulin, Paris 75005, France.
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Tanaka T, Nakano T, Hozumi Y, Martelli AM, Goto K. Regulation of p53 and NF-κB transactivation activities by DGKζ in catalytic activity-dependent and -independent manners. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1868:118953. [PMID: 33450306 DOI: 10.1016/j.bbamcr.2021.118953] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 12/15/2020] [Accepted: 01/02/2021] [Indexed: 01/03/2023]
Abstract
Diacylglycerol kinase (DGK) constitutes a family of enzymes that phosphorylate diacylglycerol to phosphatidic acid (PA). These lipids serve as second messengers, thereby activating distinct downstream cascades and different cellular responses. Therefore, DG-to-PA conversion activity induces a phase transition of signaling pathways. One member of the family, DGKζ, is involved closely with stress responses. Morphological data showing that DGKζ localizes predominantly to the nucleus and that it shuttles between the nucleus and the cytoplasm implicate DGKζ in the regulation of transcription factors during stress responses. Tumor suppressor p53 and NF-κB are major stress-responsive transcription factors. They exert opposing effects on cellular pathophysiology. Herein, we summarize DGKζ catalytic activity-dependent and -independent regulatory mechanisms of p53 and NF-κB transactivation activities, including p53 degradation and NF-κB nuclear translocation. We also discuss how each component of DGKζ-interacting protein complex modulates the specificity and selectivity of target gene expression.
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Affiliation(s)
- Toshiaki Tanaka
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan.
| | - Tomoyuki Nakano
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Yasukazu Hozumi
- Department of Cell Biology and Morphology, Akita University Graduate School of Medicine, Akita 010-8543, Japan
| | - Alberto M Martelli
- Department of Biomedical and Neuromotor Sciences, University of Bologna, via Irnerio 48, 40126 Bologna, Italy
| | - Kaoru Goto
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan.
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Akimoto R, Tanaka T, Nakano T, Hozumi Y, Kawamae K, Goto K. DGKζ depletion attenuates HIF-1α induction and SIRT1 expression, but enhances TAK1-mediated AMPKα phosphorylation under hypoxia. Cell Signal 2020; 71:109618. [PMID: 32224048 DOI: 10.1016/j.cellsig.2020.109618] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 03/21/2020] [Accepted: 03/25/2020] [Indexed: 12/31/2022]
Abstract
Cells cope with environmental changes through various mechanisms. Pathways involving HIF-1, SIRT1, and AMPK play major roles in energy homeostasis under stress conditions. Diacylglycerol kinase (DGK) constitutes an enzyme family that catalyzes conversion of diacylglycerol to phosphatidic acid. We reported earlier that energy depletion such as ischemia induces proteasomal degradation of DGKζ before cell death, suggesting involvement of DGKζ in energy homeostasis. This study examines how DGKζ depletion affects the regulation of HIF-1α, SIRT1, and AMPKα. Under hypoxia DGKζ depletion attenuates HIF-1α induction and SIRT1 expression, which might render cells vulnerable to energy stress. However, DGKζ depletion engenders enhanced AMPKα phosphorylation by upstream kinase TAK1 and an increase in intracellular ATP levels. Results suggest that DGKζ exerts a suppressive effect on TAK1 activity in the AMPK activation mechanism, and that DGKζ depletion might engender dysregulation of the AMPK-mediated energy sensor system.
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Affiliation(s)
- Ryo Akimoto
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan; Department of Anesthesiology, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Toshiaki Tanaka
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan.
| | - Tomoyuki Nakano
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Yasukazu Hozumi
- Department of Cell Biology and Morphology, Akita University Graduate School of Medicine, Akita 010-8543, Japan
| | - Kaneyuki Kawamae
- Department of Anesthesiology, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Kaoru Goto
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan.
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Expression and localization of diacylglycerol kinase ζ in guinea pig cochlea and its functional implication under noise-exposure stress conditions. Histochem Cell Biol 2019; 151:461-474. [PMID: 30963236 DOI: 10.1007/s00418-019-01781-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/01/2019] [Indexed: 12/31/2022]
Abstract
Cochlear hair cells are essential for the mechanotransduction of hearing. Sensorineural hearing loss can be irreversible because hair cells have a minimal ability to repair or regenerate themselves once damaged. In order to develop therapeutic interventions to prevent hair cell loss, it is necessary to understand the signaling pathway operating in cochlear hair cells and its alteration upon damage. Diacylglycerol kinase (DGK) regulates intracellular signal transduction through phosphorylation of lipidic second messenger diacylglycerol. We have previously reported characteristic expression and localization patterns of DGKs in various organs under pathophysiological conditions. Nevertheless, little is known about morphological and functional aspects of this enzyme family in the cochlea. First RT-PCR analysis reveals predominant mRNA expression of DGKα, DGKε and DGKζ. Immunohistochemical analysis shows that DGKζ localizes to the nuclei of inner hair cells (IHCs), outer hair cells (OHCs), supporting cells and spiral ganglion neurons in guinea pig cochlea under normal conditions. It is well known that loud noise exposure induces cochlear damage, thereby resulting in hair cell loss. In particular, OHCs are highly vulnerable to noise exposure than IHCs. We found that after 1 week of noise exposure DGKζ translocates from the nucleus to the cytoplasm in damage-sensitive OHCs and gradually disappears thereafter. In sharp contrast, DGKζ remains to the nucleus in damage-resistant IHCs. These results suggest that DGKζ cytoplasmic translocation is well correlated with cellular damage under noise-exposure stress conditions and is involved in delayed cell death in cochlear outer hair cells.
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Tanaka T, Iseki K, Tanaka K, Nakano T, Iino M, Goto K. DGKζ ablation engenders upregulation of p53 level in the spleen upon whole-body ionizing radiation. Adv Biol Regul 2018; 67:93-100. [PMID: 29079355 DOI: 10.1016/j.jbior.2017.09.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 09/25/2017] [Accepted: 09/26/2017] [Indexed: 06/07/2023]
Abstract
The tumor suppressor gene product p53, which coordinates the cellular response to various stresses, is subject to tight regulation by a complex network of signal transduction. The DGK family metabolizes lipidic second messenger diacylglycerol to produce phosphatidic acid. Our earlier studies showed that one isozyme, DGKζ, is involved in the regulatory mechanism of p53. In a cellular model of doxorubicin-induced DNA damage, overexpression of wild-type DGKζ suppresses p53 protein induction and reduces apoptosis, whereas knockdown of DGKζ upregulates p53 protein level and promotes apoptosis. Further examination reveals that DGKζ facilitates p53 degradation via ubiquitin-proteasome system in the cytoplasm. However, it remains undetermined whether the regulatory mechanism of DGKζ on p53 function found in cell-based experiments is also functional at the animal level. This study was conducted to elucidate this point using an experiment with DGKζ-KO mice under DNA damage induced by whole-body ionizing radiation. Our results reveal that p53 protein is induced robustly in the spleen of DGKζ-KO mice upon exposure to ionizing radiation, thereby promoting apoptosis in this organ. Taken together, the results demonstrate that DGKζ plays a sentinel role in p53 expression at the cellular and organismal levels after DNA damaging stress conditions.
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Affiliation(s)
- Toshiaki Tanaka
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan.
| | - Ken Iseki
- Department of Emergency and Critical Care Medicine, Fukushima Medical University, School of Medicine, Fukushima 960-1295, Japan
| | - Ken Tanaka
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Tomoyuki Nakano
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Mitsuyoshi Iino
- Department of Dentistry, Oral and Maxillofacial Plastic and Reconstructive Surgery, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Kaoru Goto
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan.
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Nuclear Lipids in the Nervous System: What they do in Health and Disease. Neurochem Res 2016; 42:321-336. [PMID: 27766461 DOI: 10.1007/s11064-016-2085-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 09/21/2016] [Accepted: 10/11/2016] [Indexed: 12/18/2022]
Abstract
In the last 20 years it has been widely demonstrated that cell nucleus contains neutral and polar lipids localized in nuclear membranes, nucleoli, nuclear matrix and chromatin. Nuclear lipids may show specific organization forming nuclear lipid microdomains and have both structural and functional roles. Depending on their localization, nuclear lipids play different roles such as the regulation of nuclear membrane and nuclear matrix fluidity but they also can act as platforms for vitamin and hormone function, for active chromatin anchoring, and for the regulation of gene expression, DNA duplication and transcription. Crosstalk among different kinds of lipid signalling pathways influence the physiopathology of numerous cell types. In neural cells the nuclear lipids are involved in cell proliferation, differentiation, inflammation, migration and apoptosis. Abnormal metabolism of nuclear lipids might be closely associated with tumorigenesis and neurodegenerative diseases such as Alzheimer disease and Parkinson disease among others.
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Hozumi Y, Nakano T, Tanaka T, Goto K. Localization of diacylglycerol kinase ζ in rat pancreatic islet cells under normal and streptozotocin-induced stress conditions . ACTA ACUST UNITED AC 2016. [DOI: 10.1679/aohc.76.23] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yasukazu Hozumi
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine,
| | - Tomoyuki Nakano
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine,
| | - Toshiaki Tanaka
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine,
| | - Kaoru Goto
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine,
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Tanaka T, Tsuchiya R, Hozumi Y, Nakano T, Okada M, Goto K. Reciprocal regulation of p53 and NF-κB by diacylglycerol kinase ζ. Adv Biol Regul 2015; 60:15-21. [PMID: 26521214 DOI: 10.1016/j.jbior.2015.09.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 09/30/2015] [Accepted: 09/30/2015] [Indexed: 11/29/2022]
Abstract
Diacylglycerol kinase (DGK) participates in lipid mediated-signal transduction. It phosphorylates diacylglycerol (DG) to phosphatidic acid (PA), thereby regulating the balanced control of these second messenger actions. Previous reports have described that one DGK family, DGKζ, is closely involved in stress responses under various conditions. Cellular stress response, a physiological process enabling cells to cope with an altered environment, is finely tuned through various signaling cascades and their molecular crosstalk. The major components of stress response are p53 and NF-κB. p53 generally serves as a proapoptotic transcriptional factor, whereas NF-κB promotes resistance to programmed cell death under most circumstances. Recent studies have suggested that DGKζ facilitates p53 degradation in cytoplasm through ubiquitin proteasome system and that DGKζ deletion upregulates p53 protein levels under basal and DNA-damage conditions. Counter-intuitively, however, DGKζ deletion suppresses p53 transcriptional activity despite increased p53 levels. In contrast, DGKζ knockdown engenders enhancement of NF-κB pathway in response to cytokines such as TNF-α and IL-1β. In response to these cytokines, DGKζ downregulation accelerates phosphorylation of the p65 subunit and its nuclear translocation, thereby enhancing NF-κB transcriptional activity. Furthermore, DGKζ deficiency is shown to promote increased association of p65 subunit with the transcriptional cofactor CBP. It is particularly interesting that this association is observed even under basal conditions in the absence of stimulation. These findings suggest that DGKζ plays a role in sequestration of the limiting pool of CBP/p300 between the NF-κB p65 subunit and p53, and that DGKζ downregulation shifts CBP/p300 toward the NF-κB subunit to regulate reciprocally antagonistic phenotypes of these transcription factors.
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Affiliation(s)
- Toshiaki Tanaka
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Iida-Nishi 2-2-2, Yamagata 990-9585, Japan.
| | - Rieko Tsuchiya
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Iida-Nishi 2-2-2, Yamagata 990-9585, Japan
| | - Yasukazu Hozumi
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Iida-Nishi 2-2-2, Yamagata 990-9585, Japan
| | - Tomoyuki Nakano
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Iida-Nishi 2-2-2, Yamagata 990-9585, Japan
| | - Masashi Okada
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Iida-Nishi 2-2-2, Yamagata 990-9585, Japan
| | - Kaoru Goto
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Iida-Nishi 2-2-2, Yamagata 990-9585, Japan.
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9
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Neuroprotective effect of noscapine on cerebral oxygen–glucose deprivation injury. Pharmacol Rep 2015; 67:281-8. [DOI: 10.1016/j.pharep.2014.10.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 09/17/2014] [Accepted: 10/15/2014] [Indexed: 12/14/2022]
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Roles of lipid-modulating enzymes diacylglycerol kinase and cyclooxygenase under pathophysiological conditions. Anat Sci Int 2014; 90:22-32. [PMID: 25471593 DOI: 10.1007/s12565-014-0265-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2014] [Accepted: 11/17/2014] [Indexed: 10/24/2022]
Abstract
Lipid not only represents a constituent of the plasma membrane, but also plays a pivotal role in intracellular signaling. Lipid-mediated signaling system is strictly regulated by several enzymes, which act at various steps of the lipid metabolism. Under pathological conditions, prolonged or insufficient activation of this system results in dysregulated signaling, leading to diseases such as cancer or metabolic syndrome. Of the lipid-modulating enzymes, diacylglycerol kinase (DGK) and cyclooxygenase (COX) are intimately involved in the signaling system. DGK consists of a family of enzymes that phosphorylate a second messenger diacylglycerol (DG) to produce phosphatidic acid (PA). Both DG and PA are known to activate signaling molecules such as protein kinase C. COX catalyzes the committed step in prostanoid biosynthesis, which involves the metabolism of arachidonic acid to produce prostaglandins. Previous studies have shown that the DGK and COX are engaged in a number of pathological conditions. This review summarizes the functional implications of these two enzymes in ischemia, liver regeneration, vascular events, diabetes, cancer and inflammation.
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Tsuchiya R, Tanaka T, Hozumi Y, Nakano T, Okada M, Topham MK, Iino M, Goto K. Downregulation of diacylglycerol kinase ζ enhances activation of cytokine-induced NF-κB signaling pathway. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1853:361-9. [PMID: 25450975 DOI: 10.1016/j.bbamcr.2014.11.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 10/31/2014] [Accepted: 11/10/2014] [Indexed: 01/06/2023]
Abstract
The transcription factor NF-κB family serves as a key component of many pathophysiological events such as innate and adaptive immune response, inflammation, apoptosis, and oncogenesis. Various cell signals trigger activation of the regulatory mechanisms of NF-κB, resulting in its nuclear translocation and transcriptional initiation. The diacylglycerol kinase (DGK) family, a lipid second messenger-metabolizing enzyme in phosphoinositide signaling, is shown to regulate widely various cellular processes. Results of recent studies suggest that one family member, DGKζ, is closely involved in immune and inflammatory responses. Nevertheless, little is known about the regulatory mechanism of DGKζ on NF-κB pathway in cytokine-induced inflammatory signaling. This study shows that siRNA-mediated DGKζ knockdown in HeLa cells facilitates degradation of IκB, followed by nuclear translocation of NF-κB p65 subunit. In addition, DGKζ-deficient MEFs show upregulation of p65 subunit phosphorylation at Serine 468 and 536 and its interaction with CBP transcriptional coactivator upon TNF-α stimulation. These modifications of p65 subunit might engender enhanced NF-κB transcriptional reporter assay of DGKζ knockdown cells. These findings provide further insight into the regulatory mechanisms of cytokine-induced NF-κB activation.
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Affiliation(s)
- Rieko Tsuchiya
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan; Department of Dentistry, Oral and Maxillofacial Plastic and Reconstructive Surgery, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Toshiaki Tanaka
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Yasukazu Hozumi
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Tomoyuki Nakano
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Masashi Okada
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Matthew K Topham
- Huntsman Cancer Institute, Department of Oncological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Mitsuyoshi Iino
- Department of Dentistry, Oral and Maxillofacial Plastic and Reconstructive Surgery, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Kaoru Goto
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan.
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12
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Cellular expression and localization of DGKζ-interacting NAP1-like proteins in the brain and functional implications under hypoxic stress. Histochem Cell Biol 2014; 142:461-71. [DOI: 10.1007/s00418-014-1226-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2014] [Indexed: 11/27/2022]
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Goto K, Tanaka T, Nakano T, Okada M, Hozumi Y, Topham MK, Martelli AM. DGKζ under stress conditions: “to be nuclear or cytoplasmic, that is the question”. Adv Biol Regul 2014; 54:242-253. [PMID: 24119575 DOI: 10.1016/j.jbior.2013.08.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 08/31/2013] [Indexed: 06/02/2023]
Abstract
Eukaryotic cells have evolved to possess a distinct subcellular compartment, the nucleus, separated from the cytoplasm in a manner that allows the precise operation of the chromatin, thereby permitting controlled access to the regulatory elements in the DNA for transcription and replication. In the cytoplasm, genetic information contained in the DNA sequence is translated into proteins, including enzymes that catalyze various reactions, such as metabolic processes, energy control, and responses to changing environments. One mechanism that regulates these events involves phosphoinositide turnover signaling, which generates a lipid second messenger, diacylglycerol (DG). Since DG acts as a potent activator of several signaling molecules, it should be tightly regulated to keep cellular responsiveness within a physiological range. DG kinase (DGK) metabolizes DG by phosphorylating it to generate phosphatidic acid, thus serving as a critical regulator of DG signaling. Phosphoinositide turnover is employed differentially in the nucleus and the cytoplasm. A member of the DGK family, DGKζ, localizes to the nucleus in various cell types and is considered to regulate nuclear DG signaling. Recent studies have provided evidence that DGKζ shuttles between the nucleus and the cytoplasm in neurons under pathophysiological conditions. Transport of a signal regulator between the nucleus and the cytoplasm should be a critical function for maintaining basic processes in the nucleus, such as cell cycle regulation and gene expression, and to ensure communication between nuclear processes and cytoplasmic functions. In this review, a series of studies on nucleocytoplasmic translocation of DGKζ have been summarized, and the functional implications of this phenomenon in postmitotic neurons and cancer cells under stress conditions are discussed.
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Fann DYW, Lee SY, Manzanero S, Chunduri P, Sobey CG, Arumugam TV. Pathogenesis of acute stroke and the role of inflammasomes. Ageing Res Rev 2013; 12:941-66. [PMID: 24103368 DOI: 10.1016/j.arr.2013.09.004] [Citation(s) in RCA: 253] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2013] [Revised: 09/12/2013] [Accepted: 09/19/2013] [Indexed: 12/20/2022]
Abstract
Inflammation is an innate immune response to infection or tissue damage that is designed to limit harm to the host, but contributes significantly to ischemic brain injury following stroke. The inflammatory response is initiated by the detection of acute damage via extracellular and intracellular pattern recognition receptors, which respond to conserved microbial structures, termed pathogen-associated molecular patterns or host-derived danger signals termed damage-associated molecular patterns. Multi-protein complexes known as inflammasomes (e.g. containing NLRP1, NLRP2, NLRP3, NLRP6, NLRP7, NLRP12, NLRC4, AIM2 and/or Pyrin), then process these signals to trigger an effector response. Briefly, signaling through NLRP1 and NLRP3 inflammasomes produces cleaved caspase-1, which cleaves both pro-IL-1β and pro-IL-18 into their biologically active mature pro-inflammatory cytokines that are released into the extracellular environment. This review will describe the molecular structure, cellular signaling pathways and current evidence for inflammasome activation following cerebral ischemia, and the potential for future treatments for stroke that may involve targeting inflammasome formation or its products in the ischemic brain.
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Taatjes DJ, Roth J. The Histochemistry and Cell Biology compendium: a review of 2012. Histochem Cell Biol 2013; 139:815-46. [PMID: 23665922 DOI: 10.1007/s00418-013-1098-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/29/2013] [Indexed: 01/27/2023]
Abstract
The year 2012 was another exciting year for Histochemistry and Cell Biology. Innovations in immunohistochemical techniques and microscopy-based imaging have provided the means for advances in the field of cell biology. Over 130 manuscripts were published in the journal during 2012, representing methodological advancements, pathobiology of disease, and cell and tissue biology. This annual review of the manuscripts published in the previous year in Histochemistry and Cell Biology serves as an abbreviated reference for the readership to quickly peruse and discern trends in the field over the past year. The review has been broadly divided into multiple sections encompassing topics such as method advancements, subcellular components, extracellular matrix, and organ systems. We hope that the creation of this subdivision will serve to guide the reader to a specific topic of interest, while simultaneously providing a concise and easily accessible encapsulation of other topics in the broad area of Histochemistry and Cell Biology.
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Affiliation(s)
- Douglas J Taatjes
- Department of Pathology and Microscopy Imaging Center, University of Vermont College of Medicine, 89 Beaumont Avenue, Burlington, VT 05405, USA.
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Hozumi Y, Matsui H, Sakane F, Watanabe M, Goto K. Distinct expression and localization of diacylglycerol kinase isozymes in rat retina. J Histochem Cytochem 2013; 61:462-76. [PMID: 23467923 DOI: 10.1369/0022155413483574] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Recent studies have revealed that phosphoinositide (PI) signaling molecules are expressed in mammalian retinas, suggesting their importance in its signal transduction. We previously showed that diacylglycerol kinase (DGK) isozymes are expressed in distinct patterns in rat retina at the mRNA level. However, little is known about the nature and morphological aspects of DGKs in the retina. For this study, we performed immunohistochemical analyses to investigate in the retina the expression and localization of DGK isozymes at the protein level. Here, we show that both DGKβ and DGKι localize in the outer plexiform layer, within which photoreceptor cells make contact with bipolar and horizontal cells. These isozymes exhibit distinct subcellular localization patterns: DGKι localizes to the synaptic area of bipolar cells in a punctate manner, whereas DGKβ distributes diffusely in the subsynaptic and dendritic regions of bipolar and horizontal cells. However, punctate labeling for DGKε is evident in the outer limiting membrane. DGKζ and DGKα localize predominantly to the nucleus of ganglion cells. These findings show distinct expression and localization of DGK isozymes in the retina, suggesting a different role of each isozyme.
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Affiliation(s)
- Yasukazu Hozumi
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata, Japan.
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Tanaka T, Okada M, Hozumi Y, Tachibana K, Kitanaka C, Hamamoto Y, Martelli AM, Topham MK, Iino M, Goto K. Cytoplasmic localization of DGKζ exerts a protective effect against p53-mediated cytotoxicity. J Cell Sci 2013; 126:2785-97. [DOI: 10.1242/jcs.118711] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The transcription factor p53 plays a crucial role in coordinating the cellular response to various stresses. Therefore, p53 protein levels and activity need to be kept under tight control. We report here that diacylglycerol kinase ζ (DGKζ) binds to p53 and modulates its function both in the cytoplasm and nucleus. DGKζ, one of the DGK family that metabolizes a lipid second messenger diacylglycerol, localizes primarily to the nucleus in various cell types. Recently, reports have described that excitotoxic stress induces DGKζ nucleocytoplasmic translocation in hippocampal neurons. In this study, we found that cytoplasmic DGKζ attenuates p53-mediated cytotoxicity against doxorubicin-induced DNA damage by facilitating cytoplasmic anchoring and degradation of p53 through a ubiquitin–proteasome system. Concomitantly, decreased levels of nuclear DGKζ engender down-regulation of p53 transcriptional activity. Consistent with these in vitro cellular experiments, DGKζ-deficient brain exhibits high levels of p53 protein after kainate-induced seizures and even under normal conditions. These findings provide novel insights into the regulation of p53 function and suggest that DGKζ serves as a sentinel to control p53 function both during normal homeostasis and in stress responses.
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Okada M, Hozumi Y, Tanaka T, Suzuki Y, Yanagida M, Araki Y, Evangelisti C, Yagisawa H, Topham MK, Martelli AM, Goto K. DGKζ is degraded through the cytoplasmic ubiquitin–proteasome system under excitotoxic conditions, which causes neuronal apoptosis because of aberrant cell cycle reentry. Cell Signal 2012; 24:1573-82. [DOI: 10.1016/j.cellsig.2012.03.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2012] [Accepted: 03/28/2012] [Indexed: 12/29/2022]
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