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Carboxylesterase 2 induces mitochondrial dysfunction via disrupting lipid homeostasis in oral squamous cell carcinoma. Mol Metab 2022; 65:101600. [PMID: 36113774 PMCID: PMC9508558 DOI: 10.1016/j.molmet.2022.101600] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 08/31/2022] [Accepted: 09/09/2022] [Indexed: 11/21/2022] Open
Abstract
OBJECTIVE Oral squamous cell carcinoma (OSCC) is characterized by high recurrence and metastasis and places a heavy burden on societies worldwide. Cancer cells thrive in a changing microenvironment by reprogramming lipidomic metabolic processes to provide nutrients and energy, activate oncogenic signaling pathways, and manage redox homeostasis to avoid lipotoxicity. The mechanism by which OSCC cells maintain lipid homeostasis during malignant progression is unclear. METHODS The altered expression of fatty acid (FA) metabolism genes in OSCC, compared with that in normal tissues, and in OSCC patients with or without recurrence or metastasis were determined using public data from the TCGA and GEO databases. Immunohistochemistry was performed to examine the carboxylesterase 2 (CES2) protein level in our own cohort. CCK-8 and Transwell assays and an in vivo xenograft model were used to evaluate the biological functions of CES2. Mass spectrometry and RNA sequencing were performed to determine the lipidome and transcriptome alterations induced by CES2. Mitochondrial mass, mtDNA content, mitochondrial membrane potential, ROS levels, and oxygen consumption and apoptosis rates were evaluated to determine the effects of CES2 on mitochondrial function in OSCC. RESULTS CES2 was downregulated in OSCC patients, especially those with recurrence or metastasis. CES2high OSCC patients showed better overall survival than CES2low OSCC patients. Restoring CES2 expression reduced OSCC cell viability and suppressed their migration and invasion in vitro, and it inhibited OSCC tumor growth in vivo. CES2 reprogrammed lipid metabolism in OSCC cells by hydrolyzing neutral lipid diacylglycerols (DGs) to release free fatty acids and reduce the membrane structure lipid phospholipids (PLs) synthesis. Free FAs were converted to acyl-carnitines (CARs) and transferred to mitochondria for oxidation, which induced reactive oxygen species (ROS) accumulation, mitochondrial damage, and apoptosis activation. Furthermore, the reduction in signaling lipids, e.g., DGs, PLs and substrates, suppressed PI3K/AKT/MYC signaling pathways. Restoring MYC rescued the diminished cell viability, suppressed migratory and invasive abilities, damaged mitochondria and reduced apoptosis rate induced by CES2. CONCLUSIONS We demonstrated that CES2 downregulation plays an important role in OSCC by maintaining lipid homeostasis and reducing lipotoxicity during tumor progression and may provide a potential therapeutic target for OSCC.
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Beger AW, Hauther KA, Dudzik B, Woltjer RL, Wood PL. Human Brain Lipidomics: Investigation of Formalin Fixed Brains. Front Mol Neurosci 2022; 15:835628. [PMID: 35782380 PMCID: PMC9245516 DOI: 10.3389/fnmol.2022.835628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 05/30/2022] [Indexed: 11/13/2022] Open
Abstract
Human brain lipidomics have elucidated structural lipids and lipid signal transduction pathways in neurologic diseases. Such studies have traditionally sourced tissue exclusively from brain bank biorepositories, however, limited inventories signal that these facilities may not be able to keep pace with this growing research domain. Formalin fixed, whole body donors willed to academic institutions offer a potential supplemental tissue source, the lipid profiles of which have yet to be described. To determine the potential of these subjects in lipid analysis, the lipid levels of fresh and fixed frontal cortical gray matter of human donors were compared using high resolution electrospray ionization mass spectrometry. Results revealed commensurate levels of specific triacylglycerols, diacylglycerols, hexosyl ceramides, and hydroxy hexosyl ceramides. Baseline levels of these lipid families in human fixed tissue were identified via a broader survey study covering six brain regions: cerebellar gray matter, superior cerebellar peduncle, gray and subcortical white matter of the precentral gyrus, periventricular white matter, and internal capsule. Whole body donors may therefore serve as supplemental tissue sources for lipid analysis in a variety of clinical contexts, including Parkinson's disease, Alzheimer's disease, Lewy body dementia, multiple sclerosis, and Gaucher's disease.
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Affiliation(s)
- Aaron W. Beger
- Department of Anatomy, DeBusk College of Osteopathic Medicine, Lincoln Memorial University, Harrogate, TN, United States
| | - Kathleen A. Hauther
- Metabolomics Unit, College of Veterinary Medicine, Lincoln Memorial University, Harrogate, TN, United States
| | - Beatrix Dudzik
- Department of Anatomy, DeBusk College of Osteopathic Medicine, Lincoln Memorial University, Harrogate, TN, United States
| | - Randall L. Woltjer
- Department of Neurology, Oregon Health Science University, Portland, OR, United States
- Portland VA Medical Center, Portland, OR, United States
| | - Paul L. Wood
- Metabolomics Unit, College of Veterinary Medicine, Lincoln Memorial University, Harrogate, TN, United States
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3
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Granade ME, Manigat LC, Lemke MC, Purow BW, Harris TE. Identification of ritanserin analogs that display DGK isoform specificity. Biochem Pharmacol 2022; 197:114908. [PMID: 34999054 PMCID: PMC8858877 DOI: 10.1016/j.bcp.2022.114908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 12/28/2021] [Accepted: 01/01/2022] [Indexed: 11/15/2022]
Abstract
The diacylglycerol kinase (DGK) family of lipid enzymes catalyzes the conversion of diacylglycerol (DAG) to phosphatidic acid (PA). Both DAG and PA are lipid signaling molecules that are of notable importance in regulating cell processes such as proliferation, apoptosis, and migration. There are ten mammalian DGK enzymes that appear to have distinct biological functions. DGKα has emerged as a promising therapeutic target in numerous cancers including glioblastoma (GBM) and melanoma as treatment with small molecule DGKα inhibitors results in reduced tumor sizes and prolonged survival. Importantly, DGKα has also been identified as an immune checkpoint due to its promotion of T cell anergy, and its inhibition has been shown to improve T cell activation. There are few small molecule DGKα inhibitors currently available, and the application of existing compounds to clinical settings is hindered by species-dependent variability in potency, as well as concerns regarding isotype specificity particularly amongst other type I DGKs. In order to resolve these issues, we have screened a library of compounds structurally analogous to the DGKα inhibitor, ritanserin, in an effort to identify more potent and specific alternatives. We identified two compounds that more potently and selectively inhibit DGKα, one of which (JNJ-3790339) demonstrates similar cytotoxicity in GBM and melanoma cells as ritanserin. Consistent with its inhibitor profile towards DGKα, JNJ-3790339 also demonstrated improved activation of T cells compared with ritanserin. Together our data support efforts to identify DGK isoform-selective inhibitors as a mechanism to produce pharmacologically relevant cancer therapies.
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Affiliation(s)
- Mitchell E Granade
- University of Virginia, School of Medicine, Department of Pharmacology, Charlottesville, VA, United States
| | - Laryssa C Manigat
- University of Virginia, School of Medicine, Department of Pathology, Charlottesville, VA, United States
| | - Michael C Lemke
- University of Virginia, School of Medicine, Department of Pharmacology, Charlottesville, VA, United States
| | - Benjamin W Purow
- University of Virginia, Department of Neurology, Division of Neuro-Oncology, Charlottesville, VA, United States.
| | - Thurl E Harris
- University of Virginia, School of Medicine, Department of Pharmacology, Charlottesville, VA, United States.
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4
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Recombinant human GLP-1 beinaglutide regulates lipid metabolism of adipose tissues in diet-induced obese mice. iScience 2021; 24:103382. [PMID: 34841227 PMCID: PMC8605346 DOI: 10.1016/j.isci.2021.103382] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 09/19/2021] [Accepted: 10/27/2021] [Indexed: 01/18/2023] Open
Abstract
GLP-1 analogs are a class of glucose-lowering agents with multiple benefits in diabetes, but its role in adipose tissues remains to be elucidated. The aim of this study was to determine the action of recombinant human GLP-1 (rhGLP-1) Beinaglutide (BN) in the insulin sensitivity and lipid metabolism of adipose tissues. We have shown that, after BN injection, obese mice displayed lower body weight, fat mass, and plasma lipid levels. In addition, BN promoted the insulin sensitivity in the white adipose tissues. Furthermore, we have found that the BN treatment caused significant changes in content and composition of different lipid classes, including glycerolipids, glycerophospholipids, and sphingolipids, as well as expression of genes in lipid metabolic pathways in the adipose tissues. Taken together, our data demonstrate that BN could resist HFD-induced obesity by targeting the composition of major lipid classes and the expression of genes in lipid metabolism of adipose tissues. Recombinant human GLP-1 Beinaglutide (BN) reduces high-fat-diet-induced obesity BN increases insulin sensitivity of adipocytes in vivo and in vitro BN alters lipidomic and transcriptomic profiles in adipose tissues of obese mice BN promotes thermogenic gene expression in adipose tissues
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Kano T, Tsumagari R, Nakashima A, Kikkawa U, Ueda S, Yamanoue M, Takei N, Shirai Y. RalA, PLD and mTORC1 Are Required for Kinase-Independent Pathways in DGKβ-Induced Neurite Outgrowth. Biomolecules 2021; 11:biom11121814. [PMID: 34944458 PMCID: PMC8699322 DOI: 10.3390/biom11121814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/25/2021] [Accepted: 11/29/2021] [Indexed: 11/16/2022] Open
Abstract
Diacylglycerol kinase β (DGKβ) is an enzyme that converts diacylglycerol to phosphatidic acid and is mainly expressed in the cerebral cortex, hippocampus and striatum. We previously reported that DGKβ induces neurite outgrowth and spinogenesis, contributing to higher brain functions, including emotion and memory. To elucidate the mechanisms involved in neuronal development by DGKβ, we investigated the importance of DGKβ activity in the induction of neurite outgrowth using human neuroblastoma SH-SY5Y cells. Interestingly, both wild-type DGKβ and the kinase-negative (KN) mutant partially induced neurite outgrowth, and these functions shared a common pathway via the activation of mammalian target of rapamycin complex 1 (mTORC1). In addition, we found that DGKβ interacted with the small GTPase RalA and that siRNA against RalA and phospholipase D (PLD) inhibitor treatments abolished DGKβKN-induced neurite outgrowth. These results indicate that binding of RalA and activation of PLD and mTORC1 are involved in DGKβKN-induced neurite outgrowth. Taken together with our previous reports, mTORC1 is a key molecule in both kinase-dependent and kinase-independent pathways of DGKβ-mediated neurite outgrowth, which is important for higher brain functions.
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Affiliation(s)
- Takuya Kano
- Department of Applied Chemistry in Bioscience, Graduate School of Agricultural Sciences, Kobe University, Kobe 657-8501, Japan; (T.K.); (R.T.); (S.U.); (M.Y.)
| | - Ryosuke Tsumagari
- Department of Applied Chemistry in Bioscience, Graduate School of Agricultural Sciences, Kobe University, Kobe 657-8501, Japan; (T.K.); (R.T.); (S.U.); (M.Y.)
| | - Akio Nakashima
- Division of Signal Functions, Biosignal Research Center, Kobe University, Kobe 657-8501, Japan; (A.N.); (U.K.)
- Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan
| | - Ushio Kikkawa
- Division of Signal Functions, Biosignal Research Center, Kobe University, Kobe 657-8501, Japan; (A.N.); (U.K.)
- Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan
| | - Shuji Ueda
- Department of Applied Chemistry in Bioscience, Graduate School of Agricultural Sciences, Kobe University, Kobe 657-8501, Japan; (T.K.); (R.T.); (S.U.); (M.Y.)
| | - Minoru Yamanoue
- Department of Applied Chemistry in Bioscience, Graduate School of Agricultural Sciences, Kobe University, Kobe 657-8501, Japan; (T.K.); (R.T.); (S.U.); (M.Y.)
| | - Nobuyuki Takei
- Department of Brain Tumor Biology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan;
| | - Yasuhito Shirai
- Department of Applied Chemistry in Bioscience, Graduate School of Agricultural Sciences, Kobe University, Kobe 657-8501, Japan; (T.K.); (R.T.); (S.U.); (M.Y.)
- Correspondence:
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6
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Potential role of diacylglycerol kinases in immune-mediated diseases. Clin Sci (Lond) 2021; 134:1637-1658. [PMID: 32608491 DOI: 10.1042/cs20200389] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 06/08/2020] [Accepted: 06/22/2020] [Indexed: 02/07/2023]
Abstract
The mechanism promoting exacerbated immune responses in allergy and autoimmunity as well as those blunting the immune control of cancer cells are of primary interest in medicine. Diacylglycerol kinases (DGKs) are key modulators of signal transduction, which blunt diacylglycerol (DAG) signals and produce phosphatidic acid (PA). By modulating lipid second messengers, DGK modulate the activity of downstream signaling proteins, vesicle trafficking and membrane shape. The biological role of the DGK α and ζ isoforms in immune cells differentiation and effector function was subjected to in deep investigations. DGK α and ζ resulted in negatively regulating synergistic way basal and receptor induced DAG signals in T cells as well as leukocytes. In this way, they contributed to keep under control the immune response but also downmodulate immune response against tumors. Alteration in DGKα activity is also implicated in the pathogenesis of genetic perturbations of the immune function such as the X-linked lymphoproliferative disease 1 and localized juvenile periodontitis. These findings suggested a participation of DGK to the pathogenetic mechanisms underlying several immune-mediated diseases and prompted several researches aiming to target DGK with pharmacologic and molecular strategies. Those findings are discussed inhere together with experimental applications in tumors as well as in other immune-mediated diseases such as asthma.
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7
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Taheri F, Ebrahimi SO, Shareef S, Reiisi S. Regulatory and immunomodulatory role of miR-34a in T cell immunity. Life Sci 2020; 262:118209. [PMID: 32763292 DOI: 10.1016/j.lfs.2020.118209] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 07/25/2020] [Accepted: 08/02/2020] [Indexed: 12/12/2022]
Abstract
miRNAs are a class of non-coding RNAs and very conserve molecules that negatively regulate the expression of many genes by targeting the 3' UTR of mRNAs. miRNAs are involved in the modulation of T-cell biology during the earliest and last stages and key controllers of T-cell differentiation and function. The miR-34a, as a major hub of the regulatory network of T cells, plays an important role in T cell activation. miR-34a is widely expressed in immune cells (dendritic cells, macrophages, mast cells, B cells, and T cells) and regulates their development, function, and survival. This miRNA, by targeting over 30 genes across different cellular pathways controls immune response. miR-34a expression is controlled by p53 in transcription level. As well as, miR-34a by activating dendritic cells mediates innate immune response and increases tumor-infiltrating CD8 expression T lymphocytes. In various types of cancers and autoimmune diseases, miR-34a can regulate T cell function and become a possible significant target of microRNA-based therapy. Therefore, in this review, we focus on miR-34a-related regulatory mechanisms in T cell function and understanding mechanisms and molecules involved in this network.
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Affiliation(s)
- Forough Taheri
- Department of Genetics, Sharekord Branch, Islamic Azad University, Shahrekord, Iran
| | - Seyed Omar Ebrahimi
- Department of Genetics, Faculty of Basic Sciences, Shahrekord University, Shahrekord, Iran
| | - Salar Shareef
- Department of medical laboratory science, College of Sciences, University of Raparin, Ranya, Kurdistan Region, Iraq
| | - Somayeh Reiisi
- Department of Genetics, Faculty of Basic Sciences, Shahrekord University, Shahrekord, Iran.
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8
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Subcellular Localization Relevance and Cancer-Associated Mechanisms of Diacylglycerol Kinases. Int J Mol Sci 2020; 21:ijms21155297. [PMID: 32722576 PMCID: PMC7432101 DOI: 10.3390/ijms21155297] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 07/21/2020] [Accepted: 07/24/2020] [Indexed: 12/12/2022] Open
Abstract
An increasing number of reports suggests a significant involvement of the phosphoinositide (PI) cycle in cancer development and progression. Diacylglycerol kinases (DGKs) are very active in the PI cycle. They are a family of ten members that convert diacylglycerol (DAG) into phosphatidic acid (PA), two-second messengers with versatile cellular functions. Notably, some DGK isoforms, such as DGKα, have been reported to possess promising therapeutic potential in cancer therapy. However, further studies are needed in order to better comprehend their involvement in cancer. In this review, we highlight that DGKs are an essential component of the PI cycle that localize within several subcellular compartments, including the nucleus and plasma membrane, together with their PI substrates and that they are involved in mediating major cancer cell mechanisms such as growth and metastasis. DGKs control cancer cell survival, proliferation, and angiogenesis by regulating Akt/mTOR and MAPK/ERK pathways. In addition, some DGKs control cancer cell migration by regulating the activities of the Rho GTPases Rac1 and RhoA.
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9
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Diacylglycerol kinase ζ is a negative regulator of GPVI-mediated platelet activation. Blood Adv 2020; 3:1154-1166. [PMID: 30967391 DOI: 10.1182/bloodadvances.2018026328] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 03/08/2019] [Indexed: 02/07/2023] Open
Abstract
Diacylglycerol kinases (DGKs) are a family of enzymes that convert diacylglycerol (DAG) into phosphatidic acid (PA). The ζ isoform of DGK (DGKζ) has been reported to inhibit T-cell responsiveness by downregulating intracellular levels of DAG. However, its role in platelet function remains undefined. In this study, we show that DGKζ was expressed at significant levels in both platelets and megakaryocytes and that DGKζ-knockout (DGKζ-KO) mouse platelets were hyperreactive to glycoprotein VI (GPVI) agonists, as assessed by aggregation, spreading, granule secretion, and activation of relevant signal transduction molecules. In contrast, they were less responsive to thrombin. Platelets from DGKζ-KO mice accumulated faster on collagen-coated microfluidic surfaces under conditions of arterial shear and stopped blood flow faster after ferric chloride-induced carotid artery injury. Other measures of hemostasis, as measured by tail bleeding time and rotational thromboelastometry analysis, were normal. Interestingly, DGKζ deficiency led to increased GPVI expression on the platelet and megakaryocyte surfaces without affecting the expression of other platelet surface receptors. These results implicate DGKζ as a novel negative regulator of GPVI-mediated platelet activation that plays an important role in regulating thrombus formation in vivo.
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10
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Tanguy E, Wang Q, Vitale N. Role of Phospholipase D-Derived Phosphatidic Acid in Regulated Exocytosis and Neurological Disease. Handb Exp Pharmacol 2020; 259:115-130. [PMID: 30570690 DOI: 10.1007/164_2018_180] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Lipids play a vital role in numerous cellular functions starting from a structural role as major constituents of membranes to acting as signaling intracellular or extracellular entities. Accordingly, it has been known for decades that lipids, especially those coming from diet, are important to maintain normal physiological functions and good health. On the other side, the exact molecular nature of these beneficial or deleterious lipids, as well as their precise mode of action, is only starting to be unraveled. This recent improvement in our knowledge is largely resulting from novel pharmacological, molecular, cellular, and genetic tools to study lipids in vitro and in vivo. Among these important lipids, phosphatidic acid plays a unique and central role in a great variety of cellular functions. This review will focus on the proposed functions of phosphatidic acid generated by phospholipase D in the last steps of regulated exocytosis with a specific emphasis on hormonal and neurotransmitter release and its potential impact on different neurological diseases.
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Affiliation(s)
- Emeline Tanguy
- Institut des Neurosciences Cellulaires et Intégratives, CNRS UPR 3212 and Université de Strasbourg, Strasbourg, France
| | - Qili Wang
- Institut des Neurosciences Cellulaires et Intégratives, CNRS UPR 3212 and Université de Strasbourg, Strasbourg, France
| | - Nicolas Vitale
- Institut des Neurosciences Cellulaires et Intégratives, CNRS UPR 3212 and Université de Strasbourg, Strasbourg, France.
- INSERM, Paris, Cedex 13, France.
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11
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Nakai H, Tsumagari R, Maruo K, Nakashima A, Kikkawa U, Ueda S, Yamanoue M, Saito N, Takei N, Shirai Y. mTORC1 is involved in DGKβ-induced neurite outgrowth and spinogenesis. Neurochem Int 2019; 134:104645. [PMID: 31891737 DOI: 10.1016/j.neuint.2019.104645] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 11/30/2019] [Accepted: 12/12/2019] [Indexed: 02/08/2023]
Abstract
Diacylglycerol kinase β (DGKβ) is an enzyme converting DG to phosphatidic acid (PA) and is specifically expressed in neurons, especially those in the cerebral cortex, hippocampus and striatum. We previously reported that DGKβ induces neurite outgrowth and spinogenesis, contributing to higher brain function including emotion and memory, and plasma membrane localization of DGKβ via the C1 domain and a cluster of basic amino acids at the C-terminus is necessary for its function. To clarify the mechanisms involved in neuronal development by DGKβ, we investigated whether DGKβ activity induces neurite outgrowth using human neuroblastoma SH-SY5Y cells. DGKβ induced neurite outgrowth by activation of mammalian target of rapamycin complex 1 (mTORC1) through a kinase-dependent pathway. In addition, in primary cultured cortical and hippocampal neurons, inhibition of mTORC1 abolished DGKβ induced-neurite outgrowth, branching and spinogenesis. These results indicated that DGKβ induces neurite outgrowth and spinogenesis by activating mTORC1 in a kinase-dependent pathway.
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Affiliation(s)
- Hiroko Nakai
- Department of Applied Chemistry in Bioscience, Graduate School of Agricultural Sciences & Faculty of Agriculture, Kobe University, Kobe, Japan.
| | - Ryosuke Tsumagari
- Department of Applied Chemistry in Bioscience, Graduate School of Agricultural Sciences & Faculty of Agriculture, Kobe University, Kobe, Japan.
| | - Kenta Maruo
- Department of Applied Chemistry in Bioscience, Graduate School of Agricultural Sciences & Faculty of Agriculture, Kobe University, Kobe, Japan.
| | - Akio Nakashima
- Laboratory of Cell Signaling, Biosignal Research Center, Kobe University, Kobe, Japan.
| | - Ushio Kikkawa
- Laboratory of Cell Signaling, Biosignal Research Center, Kobe University, Kobe, Japan.
| | - Shuji Ueda
- Department of Applied Chemistry in Bioscience, Graduate School of Agricultural Sciences & Faculty of Agriculture, Kobe University, Kobe, Japan.
| | - Minoru Yamanoue
- Department of Applied Chemistry in Bioscience, Graduate School of Agricultural Sciences & Faculty of Agriculture, Kobe University, Kobe, Japan.
| | - Naoaki Saito
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, Japan
| | - Nobuyuki Takei
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan.
| | - Yasuhito Shirai
- Department of Applied Chemistry in Bioscience, Graduate School of Agricultural Sciences & Faculty of Agriculture, Kobe University, Kobe, Japan.
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12
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DGKα in Neutrophil Biology and Its Implications for Respiratory Diseases. Int J Mol Sci 2019; 20:ijms20225673. [PMID: 31766109 PMCID: PMC6887790 DOI: 10.3390/ijms20225673] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 11/08/2019] [Accepted: 11/11/2019] [Indexed: 12/21/2022] Open
Abstract
Diacylglycerol kinases (DGKs) play a key role in phosphoinositide signaling by removing diacylglycerol and generating phosphatidic acid. Besides the well-documented role of DGKα and DGKζ as negative regulators of lymphocyte responses, a robust body of literature points to those enzymes, and specifically DGKα, as crucial regulators of leukocyte function. Upon neutrophil stimulation, DGKα activation is necessary for migration and a productive response. The role of DGKα in neutrophils is evidenced by its aberrant behavior in juvenile periodontitis patients, which express an inactive DGKα transcript. Together with in vitro experiments, this suggests that DGKs may represent potential therapeutic targets for disorders where inflammation, and neutrophils in particular, plays a major role. In this paper we focus on obstructive respiratory diseases, including asthma and chronic obstructive pulmonary disease (COPD), but also rare genetic diseases such as alpha-1-antitrypsin deficiency. Indeed, the biological role of DGKα is understudied outside the T lymphocyte field. The recent wave of research aiming to develop novel and specific inhibitors as well as KO mice will allow a better understanding of DGK's role in neutrophilic inflammation. Better knowledge and pharmacologic tools may also allow DGK to move from the laboratory bench to clinical trials.
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13
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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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14
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Yu W, Tang L, Lin F, Yao Y, Shen Z. DGKZ Acts as a Potential Oncogene in Osteosarcoma Proliferation Through Its Possible Interaction With ERK1/2 and MYC Pathway. Front Oncol 2019; 8:655. [PMID: 30662872 PMCID: PMC6328465 DOI: 10.3389/fonc.2018.00655] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 12/11/2018] [Indexed: 11/18/2022] Open
Abstract
Osteosarcoma (OS) is one of the most common primary bone tumors in children and young adults. The majority of osteosarcoma patients have limited alternative therapeutic options and metastatic patients generally have a poor prognosis. Thus, it is important to explore novel effective therapeutic targets in the treatment of osteosarcoma. Diacylglycerol kinase zeta (DGKZ) is a recently identified gene potentially associated with certain human carcinogenesis. However, the role of DGKZ in proliferation of osteosarcoma is still unclear. In this study, DGKZ's expression was firstly investigated in OS tumor samples and correlated with poor outcome in OS patients. Silence of DGKZ by shRNA hampered osteosarcoma cell growth and promoted cell apoptosis in vitro. In vivo, DGKZ's knockout also suppressed xenograft tumor proliferation as determined by bioluminescence imaging and weight/volume measurements. Meanwhile, Affymetrix GeneChip and Ingenuity Pathway Analysis (IPA) revealed that DGKZ knockdown resulted in a decreased activity of MYC pathway, and several target genes expression in MYC pathway were altered, including CCND1, CDKN2B, CDK6, PCNA, and EGR1. Furthermore, immunoprecipitation coupled with mass spectrometry (IP-MS) analysis was used to identify proteins that interacted with DGKZ in OS cells and revealed ERK1/2, a key MYC-interactor, to associate with DGKZ. Together, our study demonstrated that DGKZ might act as an oncogene in osteosarcoma via its possible interaction with ERK1/2 and MYC pathway.
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Affiliation(s)
- Wenxi Yu
- Department of Oncology, Affiliated Sixth People's Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Lina Tang
- Department of Oncology, Affiliated Sixth People's Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Feng Lin
- Department of Oncology, Affiliated Sixth People's Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Yang Yao
- Department of Oncology, Affiliated Sixth People's Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Zan Shen
- Department of Oncology, Affiliated Sixth People's Hospital, Shanghai Jiaotong University, Shanghai, China
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15
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Shan L, Wang D, Mao Q, Xia H. Establishment of a DGKθ Endogenous Promoter Luciferase Reporter HepG2 Cell Line for Studying the Transcriptional Regulation of DGKθ Gene. Appl Biochem Biotechnol 2018; 187:1344-1355. [PMID: 30229432 DOI: 10.1007/s12010-018-2890-4] [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: 06/21/2018] [Accepted: 09/10/2018] [Indexed: 12/29/2022]
Abstract
DGKθ protein expression levels are closely related to the development of diseases including diabetes, cancer, and neuronal disease. To investigate the transcriptional regulation of the DGKθ gene, we used CRISPR/Cas9 to generate a DGKθ endogenous promoter luciferase reporter HepG2 cell line, in which the endogenous DGKθ promoter controls the expression of the luciferase reporter gene. To test the cell line, FXR, the transcription factor for upregulating the expression of DGKθ gene, was used to validate the cell line. Furthermore, the reported agonists for the expression of DGKθ, cAMP and GW4064, the known inhibitor for DGKθ enzyme activity, R59949, and a potential regulator for DGKθ enzyme expression, EGCG (the major catechin in green tea), were applied to the reporter cell line. The results indicated that these reagents could significantly regulate the expression of reporter luciferase. Finally, four transcription factors (E2F1, c-Myc, USF1, and Bmal1) potentially binding to the DGKθ gene's upstream promoter region were tested. DGKθ expression was upregulated by c-Myc and downregulated by E2F1, which was also confirmed in wild-type HepG2 cells. We found that the cell line's luciferase activity was directly correlated with DGKθ endogenous promoter activity, suggesting that it is liable and sensitive for studying DGKθ transcriptional regulation. The study provides a useful tool for high-throughput drug screening for the treatment of DGKθ-involved diseases.
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Affiliation(s)
- Linlin Shan
- Laboratory of Gene Therapy, Department of Biochemistry, College of Life Sciences, Shaanxi Normal University, 199 South Chang'an Road, Xi'an, 710062, Shaanxi, People's Republic of China
| | - Dongyang Wang
- Laboratory of Gene Therapy, Department of Biochemistry, College of Life Sciences, Shaanxi Normal University, 199 South Chang'an Road, Xi'an, 710062, Shaanxi, People's Republic of China
| | - Qinwen Mao
- Department of Pathology, Northwestern University Feinberg School of Medicine, 303 E. Chicago Avenue, Ward 3-140, Chicago, IL, 60611, USA
| | - Haibin Xia
- Laboratory of Gene Therapy, Department of Biochemistry, College of Life Sciences, Shaanxi Normal University, 199 South Chang'an Road, Xi'an, 710062, Shaanxi, People's Republic of China.
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16
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Benziane B, Borg ML, Tom RZ, Riedl I, Massart J, Björnholm M, Gilbert M, Chibalin AV, Zierath JR. DGKζ deficiency protects against peripheral insulin resistance and improves energy metabolism. J Lipid Res 2017; 58:2324-2333. [PMID: 29066466 DOI: 10.1194/jlr.m079723] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 10/16/2017] [Indexed: 12/25/2022] Open
Abstract
Diacylglycerol kinases (DGKs) regulate the balance between diacylglycerol (DAG) and phosphatidic acid. DGKζ is highly abundant in skeletal muscle and induces fiber hypertrophy. We hypothesized that DGKζ influences functional and metabolic adaptations in skeletal muscle and whole-body fuel utilization. DAG content was increased in skeletal muscle and adipose tissue, but unaltered in liver of DGKζ KO mice. Linear growth, body weight, fat mass, and lean mass were reduced in DGKζ KO versus wild-type mice. Conversely, male DGKζ KO and wild-type mice displayed a similar robust increase in plantaris weight after functional overload, suggesting that DGKζ is dispensable for muscle hypertrophy. Although glucose tolerance was similar, insulin levels were reduced in high-fat diet (HFD)-fed DGKζ KO versus wild-type mice. Submaximal insulin-stimulated glucose transport and p-Akt Ser473 were increased, suggesting enhanced skeletal muscle insulin sensitivity. Energy homeostasis was altered in DGKζ KO mice, as evidenced by an elevated respiratory exchange ratio, independent of altered physical activity or food intake. In conclusion, DGKζ deficiency increases tissue DAG content and leads to modest growth retardation, reduced adiposity, and protection against insulin resistance. DGKζ plays a role in the control of growth and metabolic processes, further highlighting specialized functions of DGK isoforms in type 2 diabetes pathophysiology.
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Affiliation(s)
- Boubacar Benziane
- Department of Physiology and Pharmacology Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Melissa L Borg
- Department of Physiology and Pharmacology Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Robby Z Tom
- Department of Molecular Medicine and Surgery, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Isabelle Riedl
- Department of Molecular Medicine and Surgery, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Julie Massart
- Department of Molecular Medicine and Surgery, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Marie Björnholm
- Department of Molecular Medicine and Surgery, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Marc Gilbert
- Department of Molecular Medicine and Surgery, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Alexander V Chibalin
- Department of Molecular Medicine and Surgery, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Juleen R Zierath
- Department of Physiology and Pharmacology Karolinska Institutet, 171 77 Stockholm, Sweden .,Department of Molecular Medicine and Surgery, Karolinska Institutet, 171 77 Stockholm, Sweden
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17
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Weißflog L, Becker N, Bossert N, Freudenberg F, Kittel-Schneider S, Reif A. Expressional profile of the diacylglycerol kinase eta gene DGKH. Eur Arch Psychiatry Clin Neurosci 2017; 267:445-454. [PMID: 27085324 DOI: 10.1007/s00406-016-0695-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 04/09/2016] [Indexed: 11/25/2022]
Abstract
Bipolar disorder (BPD) is a genetically complex mental disorder, which is characterized by recurrent depressive and manic episodes, occurring with a typical cyclical course. In a recent study, we were able to identify a risk haplotype for BPD, as well as for unipolar depression and adult attention-deficit/hyperactivity disorder (ADHD), within the DGKH gene. DGKH codes for the eta (η) isoform of diacylglycerol kinase, which is involved in the phosphoinositol pathway. In the present study, we determined the expressional profile of Dgkh using quantitative real-time PCR (qPCR), in situ hybridization and immunohistological staining in the human and in the mouse brain. Expression studies showed that two different Dgkh transcripts exhibited distinct occurrence in a variety of murine tissues and also differed in their expression levels. The proteins encoded by those transcripts differ in functional protein domains suggesting distinct biochemical and cell biological properties and functions. qPCR analyses revealed an increase in Dgkh expression during mouse brain development indicating a possible role of this kinase in late developmental stages. Immunostainings revealed strong Dgkh expression in neurons of the hippocampus and the cerebellum of the murine brain, whereas highest expression levels of DGKH in the human brain were found in the striatum. Taken together, our studies revealed expressional changes during mouse brain development and occurrence of Dgkη in neurons of regions that have been linked to BPD as well as ADHD in humans providing evidence for the implication of DGKH in those disorders.
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Affiliation(s)
- Lena Weißflog
- Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, University Hospital of Frankfurt, Heinrich-Hoffmann-Str. 10, 60528, Frankfurt, Germany.
| | - Nils Becker
- Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, University Hospital of Würzburg, Füchsleinstr. 15, 97080, Würzburg, Germany
- Department of Behavioral Physiology and Sociobiology, Theodor-Boveri-Institute of Bioscience, University of Würzburg, Würzburg, Germany
| | - Nelli Bossert
- Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, University Hospital of Würzburg, Füchsleinstr. 15, 97080, Würzburg, Germany
- Leiden Institute of Physics, Leiden University, Leiden, Netherlands
| | - Florian Freudenberg
- Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, University Hospital of Frankfurt, Heinrich-Hoffmann-Str. 10, 60528, Frankfurt, Germany
| | - Sarah Kittel-Schneider
- Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, University Hospital of Frankfurt, Heinrich-Hoffmann-Str. 10, 60528, Frankfurt, Germany
| | - Andreas Reif
- Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, University Hospital of Frankfurt, Heinrich-Hoffmann-Str. 10, 60528, Frankfurt, Germany
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18
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Aït Ghezali L, Arbabian A, Roudot H, Brouland JP, Baran-Marszak F, Salvaris E, Boyd A, Drexler HG, Enyedi A, Letestu R, Varin-Blank N, Papp B. Induction of endoplasmic reticulum calcium pump expression during early leukemic B cell differentiation. J Exp Clin Cancer Res 2017; 36:87. [PMID: 28651627 PMCID: PMC5485704 DOI: 10.1186/s13046-017-0556-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 06/18/2017] [Indexed: 11/15/2022] Open
Abstract
Background Endoplasmic reticulum (ER) calcium storage and release play important roles in B lymphocyte maturation, survival, antigen-dependent cell activation and immunoglobulin synthesis. Calcium is accumulated in the endoplasmic reticulum (ER) by Sarco/Endoplasmic Reticulum Calcium ATPases (SERCA enzymes). Because lymphocyte function is critically dependent on SERCA activity, it is important to understand qualitative and quantitative changes of SERCA protein expression that occur during B lymphoid differentiation and leukemogenesis. Methods In this work we investigated the modulation of SERCA expression during the pharmacologically induced differentiation of leukemic precursor B lymphoblast cell lines that carry the E2A-PBX1 fusion oncoprotein. Changes of SERCA levels during differentiation were determined and compared to those of established early B lymphoid differentiation markers. SERCA expression of the cells was compared to that of mature B cell lines as well, and the effect of the direct inhibition of SERCA-dependent calcium transport on the differentiation process was investigated. Results We show that E2A-PBX1+ leukemia cells simultaneously express SERCA2 and SERCA3-type calcium pumps; however, their SERCA3 expression is markedly inferior to that of mature B cells. Activation of protein kinase C enzymes by phorbol ester leads to phenotypic differentiation of the cells, and this is accompanied by the induction of SERCA3 expression. Direct pharmacological inhibition of SERCA-dependent calcium transport during phorbol ester treatment interferes with the differentiation process. Conclusion These data show that the calcium pump composition of the ER is concurrent with increased SERCA3 expression during the differentiation of precursor B acute lymphoblastic leukemia cells, that a cross-talk exists between SERCA function and the control of differentiation, and that SERCA3 may constitute an interesting new marker for the study of early B cell phenotype. Electronic supplementary material The online version of this article (doi:10.1186/s13046-017-0556-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lamia Aït Ghezali
- Institut National de la Santé et de la Recherche Médicale, U978, Bobigny, France.,Université Paris-13, PRES Sorbonne Paris-Cité, 74, rue Marcel Cachin 93017, Bobigny, France
| | | | - Hervé Roudot
- Institut National de la Santé et de la Recherche Médicale, U978, Bobigny, France.,Université Paris-13, PRES Sorbonne Paris-Cité, 74, rue Marcel Cachin 93017, Bobigny, France.,Service d'Hématologie Biologique, Hôpitaux Universitaires Paris Seine-Saint-Denis, AP-HP, Hôpital Avicenne, Bobigny, France
| | | | - Fanny Baran-Marszak
- Institut National de la Santé et de la Recherche Médicale, U978, Bobigny, France.,Université Paris-13, PRES Sorbonne Paris-Cité, 74, rue Marcel Cachin 93017, Bobigny, France.,Service d'Hématologie Biologique, Hôpitaux Universitaires Paris Seine-Saint-Denis, AP-HP, Hôpital Avicenne, Bobigny, France
| | - Evelyn Salvaris
- Immunology Research Centre, St Vincent's Hospital, Melbourne, VIC, Australia
| | - Andrew Boyd
- Department of Medicine, University of Queensland, Queensland, Australia
| | - Hans G Drexler
- Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Brauschweig, Germany
| | - Agnes Enyedi
- Second Institute of Pathology, Semmelweis University Medical School, Budapest, Hungary
| | - Remi Letestu
- Institut National de la Santé et de la Recherche Médicale, U978, Bobigny, France.,Université Paris-13, PRES Sorbonne Paris-Cité, 74, rue Marcel Cachin 93017, Bobigny, France.,Service d'Hématologie Biologique, Hôpitaux Universitaires Paris Seine-Saint-Denis, AP-HP, Hôpital Avicenne, Bobigny, France
| | - Nadine Varin-Blank
- Institut National de la Santé et de la Recherche Médicale, U978, Bobigny, France.,Université Paris-13, PRES Sorbonne Paris-Cité, 74, rue Marcel Cachin 93017, Bobigny, France
| | - Bela Papp
- Institut National de la Santé et de la Recherche Médicale, U978, Bobigny, France. .,Université Paris-13, PRES Sorbonne Paris-Cité, 74, rue Marcel Cachin 93017, Bobigny, France. .,U978 Inserm, UFR SMBH, Université Paris-13, 74, rue Marcel Cachin, 93017, Bobigny, France.
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19
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Elhalem E, Donadío LG, Zhou X, Lewin NE, Garcia LC, Lai CC, Kelley JA, Peach ML, Blumberg PM, Comin MJ. Exploring the influence of indololactone structure on selectivity for binding to the C1 domains of PKCα, PKCε, and RasGRP. Bioorg Med Chem 2017; 25:2971-2980. [PMID: 28392275 PMCID: PMC5493039 DOI: 10.1016/j.bmc.2017.03.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 03/06/2017] [Accepted: 03/09/2017] [Indexed: 11/23/2022]
Abstract
C1 domain-containing proteins, such as protein kinase C (PKC), have a central role in cellular signal transduction. Their involvement in many diseases, including cancer, cardiovascular disease, and immunological and neurological disorders has been extensively demonstrated and has prompted a search for small molecules to modulate their activity. By employing a diacylglycerol (DAG)-lactone template, we have been able to develop ultra potent analogs of diacylglycerol with nanomolar binding affinities approaching those of complex natural products such as phorbol esters and bryostatins. One current challenge is the development of selective ligands capable of discriminating between different protein family members. Recently, structure-activity relationship studies have shown that the introduction of an indole ring as a DAG-lactone substituent yielded selective Ras guanine nucleotide-releasing protein (RasGRP1) activators when compared to PKCα and PKCε. In the present work, we examine the effects of ligand selectivity relative to the orientation of the indole ring and the nature of the DAG-lactone template itself. Our results show that the indole ring must be attached to the lactone moiety through the sn-2 position in order to achieve RasGRP1 selectivity.
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Affiliation(s)
- Eleonora Elhalem
- Laboratory of Organic Synthesis, Center of Research and Development in Chemistry, National Institute of Industrial Technology, Buenos Aires, Argentina
| | - Lucía Gandolfi Donadío
- Laboratory of Organic Synthesis, Center of Research and Development in Chemistry, National Institute of Industrial Technology, Buenos Aires, Argentina
| | - Xiaoling Zhou
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Nancy E Lewin
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Lia C Garcia
- Laboratory of Organic Synthesis, Center of Research and Development in Chemistry, National Institute of Industrial Technology, Buenos Aires, Argentina
| | - Christopher C Lai
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, National Institutes of Health, Frederick, MD 21702, USA
| | - James A Kelley
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, National Institutes of Health, Frederick, MD 21702, USA
| | - Megan L Peach
- Basic Science Program, Leidos Biomedical Research Inc., Chemical Biology Laboratory, Frederick National Laboratory for Cancer Research, National Institutes of Health, Frederick, MD 21702, USA
| | - Peter M Blumberg
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - María J Comin
- Laboratory of Organic Synthesis, Center of Research and Development in Chemistry, National Institute of Industrial Technology, Buenos Aires, Argentina.
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20
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Mannerås-Holm L, Schönke M, Brozinick JT, Vetterli L, Bui HH, Sanders P, Nascimento EBM, Björnholm M, Chibalin AV, Zierath JR. Diacylglycerol kinase ε deficiency preserves glucose tolerance and modulates lipid metabolism in obese mice. J Lipid Res 2017; 58:907-915. [PMID: 28246337 DOI: 10.1194/jlr.m074443] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 02/13/2017] [Indexed: 12/19/2022] Open
Abstract
Diacylglycerol kinases (DGKs) catalyze the phosphorylation and conversion of diacylglycerol (DAG) into phosphatidic acid. DGK isozymes have unique primary structures, expression patterns, subcellular localizations, regulatory mechanisms, and DAG preferences. DGKε has a hydrophobic segment that promotes its attachment to membranes and shows substrate specificity for DAG with an arachidonoyl acyl chain in the sn-2 position of the substrate. We determined the role of DGKε in the regulation of energy and glucose homeostasis in relation to diet-induced insulin resistance and obesity using DGKε-KO and wild-type mice. Lipidomic analysis revealed elevated unsaturated and saturated DAG species in skeletal muscle of DGKε KO mice, which was paradoxically associated with increased glucose tolerance. Although skeletal muscle insulin sensitivity was unaltered, whole-body respiratory exchange ratio was reduced, and abundance of mitochondrial markers was increased, indicating a greater reliance on fat oxidation and intracellular lipid metabolism in DGKε KO mice. Thus, the increased intracellular lipids in skeletal muscle from DGKε KO mice may undergo rapid turnover because of increased mitochondrial function and lipid oxidation, rather than storage, which in turn may preserve insulin sensitivity. In conclusion, DGKε plays a role in glucose and energy homeostasis by modulating lipid metabolism in skeletal muscle.
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Affiliation(s)
- Louise Mannerås-Holm
- Section of Integrative Physiology, Department of Molecular Medicine and Surgery and Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Milena Schönke
- Section of Integrative Physiology, Department of Molecular Medicine and Surgery and Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | | | - Laurène Vetterli
- Section of Integrative Physiology, Department of Molecular Medicine and Surgery and Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Hai-Hoang Bui
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Philip Sanders
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Emmani B M Nascimento
- Section of Integrative Physiology, Department of Molecular Medicine and Surgery and Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Marie Björnholm
- Section of Integrative Physiology, Department of Molecular Medicine and Surgery and Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Alexander V Chibalin
- Section of Integrative Physiology, Department of Molecular Medicine and Surgery and Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Juleen R Zierath
- Section of Integrative Physiology, Department of Molecular Medicine and Surgery and Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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21
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Diacylglycerol kinase ε localizes to subsurface cisterns of cerebellar Purkinje cells. Cell Tissue Res 2017; 368:441-458. [PMID: 28191598 DOI: 10.1007/s00441-017-2579-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 01/16/2017] [Indexed: 10/20/2022]
Abstract
Following activation of Gq protein-coupled receptors, phospholipase C yields a pair of second messengers: diacylglycerol (DG) and inositol 1,4,5-trisphosphate. Diacylglycerol kinase (DGK) phosphorylates DG to produce phosphatidic acid, another second messenger. Of the DGK family, DGKε is the only DGK isoform that exhibits substrate specificity for DG with an arachidonoyl acyl chain at the sn-2 position. Recently, we demonstrated that hydrophobic residues in the N-terminus of DGKε play an important role in targeting the endoplasmic reticulum in transfected cells. However, its cellular expression and subcellular localization in the brain remain elusive. In the present study, we investigate this issue using specific DGKε antibody. DGKε was richly expressed in principal neurons of higher brain regions, including pyramidal cells in the hippocampus and neocortex, medium spiny neurons in the striatum and Purkinje cells in the cerebellum. In Purkinje cells, DGKε was localized to the subsurface cisterns and colocalized with inositol 1,4,5-trisphosphate receptor-1 in dendrites and axons. In dendrites of Purkinje cells, DGKε was also distributed in close apposition to DG lipase-α, which catalyzes arachidonoyl-DG to produce 2-arachidonoyl glycerol, a major endocannabinoid in the brain. Behaviorally, DGKε-knockout mice exhibited hyper-locomotive activities and impaired motor coordination and learning. These findings suggest that DGKε plays an important role in neuronal and brain functions through its distinct neuronal expression and subcellular localization and also through coordinated arrangement with other molecules involving the phosphoinositide signaling pathway.
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22
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Murakami E, Shionoya T, Komenoi S, Suzuki Y, Sakane F. Cloning and Characterization of Novel Testis-Specific Diacylglycerol Kinase η Splice Variants 3 and 4. PLoS One 2016; 11:e0162997. [PMID: 27643686 PMCID: PMC5028035 DOI: 10.1371/journal.pone.0162997] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 08/31/2016] [Indexed: 01/04/2023] Open
Abstract
Diacylglycerol kinase (DGK) phosphorylates DG to generate phosphatidic acid. Recently, we found that a new alternative splicing product of the DGKη gene, DGKη3, which lacks exon 26 encoding 31 amino acid residues, was expressed only in the secondary spermatocytes and round spermatids of the testis. In this study, we cloned the full length DGKη3 gene and confirmed the endogenous expression of its protein product. During the cloning procedure, we found a new testis-specific alternative splicing product of the DGKη gene, DGKη4, which lacks half of the catalytic domain. We examined the DGK activity and subcellular localization of DGKη3 and η4. DGKη3 had almost the same activity as DGKη1, whereas the activity of DGKη4 was not detectable. In resting NEC8 cells (human testicular germ cell tumor cell line), DGKη1, η3 and η4 were broadly distributed in the cytoplasm. When osmotically shocked, DGKη1 and η4 were distributed in punctate vesicles in the cytoplasm. In contrast, DGKη3 was partly translocated to the plasma membrane and co-localized with the actin cytoskeleton. These results suggest that DGKη3 and η4 have properties different from those of DGKη1 and that they play roles in the testis in a different manner.
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Affiliation(s)
- Eri Murakami
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
| | - Takao Shionoya
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
| | - Suguru Komenoi
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
| | - Yuji Suzuki
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
| | - Fumio Sakane
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
- * E-mail:
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23
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Tu-Sekine B, Goldschmidt HL, Raben DM. DGK-θ: Structure, Enzymology, and Physiological Roles. Front Cell Dev Biol 2016; 4:101. [PMID: 27683659 PMCID: PMC5021689 DOI: 10.3389/fcell.2016.00101] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 08/29/2016] [Indexed: 12/13/2022] Open
Abstract
Diacylglycerol kinases (DGKs) are a family of enzymes that catalyze the ATP-dependent phosphorylation of diacylglycerol (DAG) to phosphatidic acid (PtdOH). The recognition of the importance of these enzymes has been increasing ever since it was determined that they played a role in the phosphatidylinositol (PtdIns) cycle and a number of excellent reviews have already been written [(see van Blitterswijk and Houssa, 2000; Kanoh et al., 2002; Mérida et al., 2008; Tu-Sekine and Raben, 2009, 2011; Shulga et al., 2011; Tu-Sekine et al., 2013) among others]. We now know there are ten mammalian DGKs that are organized into five classes. DGK-θ is the lone member of the Type V class of DGKs and remains as one of the least studied. This review focuses on our current understanding of the structure, enzymology, regulation, and physiological roles of this DGK and suggests some future areas of research to understand this DGK isoform.
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Affiliation(s)
- Becky Tu-Sekine
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine Baltimore, MD, USA
| | - Hana L Goldschmidt
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine Baltimore, MD, USA
| | - Daniel M Raben
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine Baltimore, MD, USA
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24
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Tabet R, Vitale N, Moine H. Fragile X syndrome: Are signaling lipids the missing culprits? Biochimie 2016; 130:188-194. [PMID: 27597551 DOI: 10.1016/j.biochi.2016.09.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 09/01/2016] [Indexed: 10/21/2022]
Abstract
Fragile X syndrome (FXS) is the most common cause of inherited intellectual disability and autism. FXS results from the absence of FMRP, an RNA binding protein associated to ribosomes that influences the translation of specific mRNAs in post-synaptic compartments of neurons. The main molecular consequence of the absence of FMRP is an excessive translation of neuronal protein in several areas of the brain. This local protein synthesis deregulation is proposed to underlie the defect in synaptic plasticity responsible for FXS. Recent findings in neurons of the fragile X mouse model (Fmr1-KO) uncovered another consequence of the lack of FMRP: a deregulation of the diacylglycerol (DAG)/phosphatidic acid (PA) homeostasis. DAG and PA are two interconvertible lipids that influence membrane architecture and that act as essential signaling molecules that activate various downstream effectors, including master regulators of local protein synthesis and actin polymerization. As a consequence, DAG and PA govern a variety of cellular processes, including cell proliferation, vesicle/membrane trafficking and cytoskeletal organization. At the synapse, the level of these lipids is proposed to influence the synaptic activation status. FMRP appears as a master regulator of this neuronal process by controlling the translation of a diacylglycerol kinase enzyme that converts DAG into PA. The deregulated levels of DAG and PA caused by the absence of FMRP could represent a novel therapeutic target for the treatment of FXS.
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Affiliation(s)
- Ricardos Tabet
- Mass General Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Nicolas Vitale
- Institut des Neurosciences Cellulaires et Intégratives, UPR3212 CNRS, Université de Strasbourg, 67084 Strasbourg, France
| | - Hervé Moine
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U964, 67404 Illkirch, France; Université de Strasbourg, 67084 Strasbourg, France.
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25
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Distinct 1-monoacylglycerol and 2-monoacylglycerol kinase activities of diacylglycerol kinase isozymes. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2016; 1864:1170-1176. [PMID: 27346717 DOI: 10.1016/j.bbapap.2016.06.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 06/15/2016] [Accepted: 06/22/2016] [Indexed: 02/02/2023]
Abstract
Diacylglycerol kinase (DGK) consists of ten isozymes and is involved in a wide variety of patho-physiological events. However, the enzymological properties of DGKs have not been fully understood. In this study, we performed a comprehensive analysis on the 1-monoacylglycerol kinase (MGK) and 2-MGK activities of ten DGK isozymes. We revealed that type I (α, β and γ), type II (δ, η and κ) and type III (ε) DGKs have 7.9-19.2% 2-MGK activity compared to their DGK activities, whereas their 1-MGK activities were <3.0%. Both the 1-MGK and 2-MGK activities of the type IV DGKs (ζ and ι) were <1% relative to their DGK activities. Intriguingly, type V DGKθ has approximately 6% 1-MGK activity and <2% 2-MGK activity compared to its DGK activity. Purified DGKθ exhibited the same results, indicating that its 1-MGK activity is intrinsic. Therefore, DGK isozymes are categorized into three types with respect to their 1-MGK and 2-MGK activities: those having (1) 2-MGK activity relatively stronger than their 1-MGK activity (types I-III), (2) only negligible 1-MGK and 2-MGK activities (type IV), and (3) 1-MGK activity stronger than its 2-MGK activity (type V). The 1-MGK activity of DGKθ and the 2-MGK activity of DGKα were stronger than those of the acylglycerol kinase reported as 1-MGK and 2-MGK to date. The presence or absence of 1-MGK and 2-MGK activities may be essential to the patho-physiological functions of each DGK isozyme.
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Liu K, Kunii N, Sakuma M, Yamaki A, Mizuno S, Sato M, Sakai H, Kado S, Kumagai K, Kojima H, Okabe T, Nagano T, Shirai Y, Sakane F. A novel diacylglycerol kinase α-selective inhibitor, CU-3, induces cancer cell apoptosis and enhances immune response. J Lipid Res 2016; 57:368-79. [PMID: 26768655 DOI: 10.1194/jlr.m062794] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Indexed: 02/02/2023] Open
Abstract
Diacylglycerol kinase (DGK) consists of 10 isozymes. The α-isozyme enhances the proliferation of cancer cells. However, DGKα facilitates the nonresponsive state of immunity known as T-cell anergy; therefore, DGKα enhances malignant traits and suppresses immune surveillance. The aim of this study was to identify a novel small molecule that selectively and potently inhibits DGKα activity. We screened a library containing 9,600 chemical compounds using a newly established high-throughput DGK assay. As a result, we have obtained a promising compound, 5-[(2E)-3-(2-furyl)prop-2-enylidene]-3-[(phenylsulfonyl)amino]2-thioxo-1,3-thiazolidin-4-one) (CU-3), which selectively inhibited DGKα with an IC50 value of 0.6 μM. CU-3 targeted the catalytic region, but not the regulatory region, of DGKα. CU-3 competitively reduced the affinity of DGKα for ATP, but not diacylglycerol or phosphatidylserine. Moreover, this compound induced apoptosis in HepG2 hepatocellular carcinoma and HeLa cervical cancer cells while simultaneously enhancing the interleukin-2 production of Jurkat T cells. Taken together, these results indicate that CU-3 is a selective and potent inhibitor for DGKα and can be an ideal anticancer drug candidate that attenuates cancer cell proliferation and simultaneously enhances immune responses including anticancer immunity.
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Affiliation(s)
- Ke Liu
- Department of Chemistry, Chiba University, Chiba 263-8522, Japan
| | - Naoko Kunii
- Department of Chemistry, Chiba University, Chiba 263-8522, Japan
| | - Megumi Sakuma
- Department of Applied Chemistry in Bioscience, Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan
| | - Atsumi Yamaki
- Department of Chemistry, Chiba University, Chiba 263-8522, Japan
| | - Satoru Mizuno
- Department of Chemistry, Chiba University, Chiba 263-8522, Japan
| | - Mayu Sato
- Department of Chemistry, Chiba University, Chiba 263-8522, Japan
| | - Hiromichi Sakai
- Department of Chemistry, Chiba University, Chiba 263-8522, Japan
| | - Sayaka Kado
- Graduate School of Science and Center for Analytical Instrumentation, Chiba University, Chiba 263-8522, Japan
| | - Kazuo Kumagai
- Drug Discovery Initiative, University of Tokyo, Tokyo 113-0033, Japan
| | - Hirotatsu Kojima
- Drug Discovery Initiative, University of Tokyo, Tokyo 113-0033, Japan
| | - Takayoshi Okabe
- Drug Discovery Initiative, University of Tokyo, Tokyo 113-0033, Japan
| | - Tetsuo Nagano
- Drug Discovery Initiative, University of Tokyo, Tokyo 113-0033, Japan
| | - Yasuhito Shirai
- Department of Applied Chemistry in Bioscience, Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan
| | - Fumio Sakane
- Department of Chemistry, Chiba University, Chiba 263-8522, Japan
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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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Expression and localization of the diacylglycerol kinase family and of phosphoinositide signaling molecules in adrenal gland. Cell Tissue Res 2015; 362:295-305. [PMID: 26003177 DOI: 10.1007/s00441-015-2199-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 04/13/2015] [Indexed: 10/23/2022]
Abstract
Adrenal glands play a central role in the secretion of steroid hormones and catecholamines. Previous studies have revealed that molecules engaged in phosphoinositide (PI) turnover are expressed in the adrenal gland, suggesting the importance of PI signaling in adrenal signal transduction. Diacylglycerol kinase (DGK) catalyzes the phosphorylation of diacylglycerol (DG), a major second messenger in the PI signaling cascade. The DGK family is expressed in distinct patterns in endocrine organs at the mRNA and protein levels. Nevertheless, little is known about the characteristics and morphological aspects of DGKs in the adrenal gland. We have performed immunohistochemical analyses to investigate the expression and localization of DGK isozymes, together with PI signaling molecules, in the adrenal gland at the protein level. Our results show that the DGK family and a set of PI signaling molecules are expressed intensely in zona glomerulosa cells and medullary chromaffin cells in the adrenal gland. In adrenal cells, DGKγ localizes to the Golgi complex, DGKε to the plasma membrane, and DGKζ to the nucleus. These findings show the distinct expression and subcellular localization of DGK isozymes and PI signaling molecules in the adrenal gland, suggesting that each DGK isozyme has a role in signal transduction in adrenal cells, especially in the zona glomerulosa and medulla.
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Mannerås-Holm L, Kirchner H, Björnholm M, Chibalin AV, Zierath JR. mRNA expression of diacylglycerol kinase isoforms in insulin-sensitive tissues: effects of obesity and insulin resistance. Physiol Rep 2015; 3:3/4/e12372. [PMID: 25847921 PMCID: PMC4425976 DOI: 10.14814/phy2.12372] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Diacylglycerol kinase (DGK) isoforms regulate signal transduction and lipid metabolism. DGKδ deficiency leads to hyperglycemia, peripheral insulin resistance, and metabolic inflexibility. Thus, dysregulation of other DGK isoforms may play a role in metabolic dysfunction. We investigated DGK isoform mRNA expression in extensor digitorum longus (EDL) and soleus muscle, liver as well as subcutaneous and epididymal adipose tissue in C57BL/6J mice and obese and insulin-resistant ob/ob mice. All DGK isoforms, except for DGKκ, were detectable, although with varying mRNA expression. Liver DGK expression was generally lowest, with several isoforms undetectable. In soleus muscle, subcutaneous and epididymal adipose tissue, DGKδ was the most abundant isoform. In EDL muscle, DGKα and DGKζ were the most abundant isoforms. In liver, DGKζ was the most abundant isoform. Comparing obese insulin-resistant ob/ob mice to lean C57BL/6J mice, DGKβ, DGKι, and DGKθ were increased and DGKε expression was decreased in EDL muscle, while DGKβ, DGKη and DGKθ were decreased and DGKδ and DGKι were increased in soleus muscle. In liver, DGKδ and DGKζ expression was increased in ob/ob mice. DGKη was increased in subcutaneous fat, while DGKζ was increased and DGKβ, DGKδ, DGKη and DGKε were decreased in epididymal fat from ob/ob mice. In both adipose tissue depots, DGKα and DGKγ were decreased and DGKι was increased in ob/ob mice. In conclusion, DGK mRNA expression is altered in an isoform- and tissue-dependent manner in obese insulin-resistant ob/ob mice. DGK isoforms likely have divergent functional roles in distinct tissues, which may contribute to metabolic dysfunction.
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Affiliation(s)
- Louise Mannerås-Holm
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Henriette Kirchner
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Marie Björnholm
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Alexander V Chibalin
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Juleen R Zierath
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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King BS, Lu L, Yu M, Jiang Y, Standard J, Su X, Zhao Z, Wang W. Lipidomic profiling of di- and tri-acylglycerol species in weight-controlled mice. PLoS One 2015; 10:e0116398. [PMID: 25706122 PMCID: PMC4337902 DOI: 10.1371/journal.pone.0116398] [Citation(s) in RCA: 6] [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: 07/14/2014] [Accepted: 12/09/2014] [Indexed: 01/19/2023] Open
Abstract
Weight control by dietary calorie restriction (DCR) or exercise has been shown to prevent cancer in various models. However, the mechanisms as to how weight control is beneficial are not well understood. While previous reports have investigated the effects of weight control on total lipid levels or lipid composition within cellular membranes, there has been little work surrounding changes to individual lipids following weight control interventions. In this study, using a model of skin carcinogenesis centered on the tumor promotion stage, CD-1 mice were randomly assigned into 4 groups: ad libitum and sedentary (control), ad libitum with exercise (AL+Exe), exercise with pair feeding of a diet isocaloric with control (PF+Exe), and sedentary with 20% DCR compared to control. After ten weeks, body weight and body fat percentages significantly decreased in the PF+Exe and DCR groups but not AL+Exe when compared with sedentary controls. Murine skin and plasma samples were obtained for analysis. Lipidomics using electrospray ionization MS/MS was employed to profile triacylglycerol (TG) and diacylglycerol (DG) species. Both plasma and tissue TG species containing fatty acid chains with length 18:1 were significantly decreased following DCR when compared to sedentary control animals. In regards to DG, the most significant changes occurred in the plasma. DG species containing fatty acids with lengths 16:1 or 18:1 were significantly decreased in PF+Exe and DCR groups when compared to sedentary controls. Due to the significant role of TG in energy storage and DG in cellular signaling, our findings of the effects of weight control on individual TG and DG species in plasma and skin tissue following exposure to a tumor promoter, may provide insight into the mechanism of weight control on cancer prevention.
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Affiliation(s)
- Brenee S. King
- Department of Human Nutrition, Kansas State University, Manhattan, KS 66506, United States of America
| | - Lizhi Lu
- Institute of Animal Husbandry & Veterinary Science, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Miao Yu
- Department of Human Nutrition, Kansas State University, Manhattan, KS 66506, United States of America
| | - Yu Jiang
- Department of Human Nutrition, Kansas State University, Manhattan, KS 66506, United States of America
| | - Joseph Standard
- Department of Human Nutrition, Kansas State University, Manhattan, KS 66506, United States of America
| | - Xiaoyu Su
- Department of Human Nutrition, Kansas State University, Manhattan, KS 66506, United States of America
| | - Zhihui Zhao
- Institute for Agri-food Standards and Testing Technology, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China
| | - Weiqun Wang
- Department of Human Nutrition, Kansas State University, Manhattan, KS 66506, United States of America
- * E-mail:
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31
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Involvement of diacylglycerol kinase β in the spine formation at distal dendrites of striatal medium spiny neurons. Brain Res 2015; 1594:36-45. [DOI: 10.1016/j.brainres.2014.11.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 10/23/2014] [Accepted: 11/06/2014] [Indexed: 01/15/2023]
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32
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Ammar MR, Kassas N, Bader MF, Vitale N. Phosphatidic acid in neuronal development: A node for membrane and cytoskeleton rearrangements. Biochimie 2014; 107 Pt A:51-7. [DOI: 10.1016/j.biochi.2014.07.026] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 07/30/2014] [Indexed: 12/22/2022]
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Yamamoto M, Tanaka T, Hozumi Y, Saino-Saito S, Nakano T, Tajima K, Kato T, Goto K. Expression of mRNAs for the diacylglycerol kinase family in immune cells during an inflammatory reaction. Biomed Res 2014; 35:61-8. [PMID: 24573202 DOI: 10.2220/biomedres.35.61] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Phosphoinositide metabolism is intimately involved in cellular signal transduction. In response to extracellular stimuli, it generates diacylglycerol (DG), which serves as a lipid second messenger molecule to activate various proteins in various organs under pathophysiological conditions. Diacylglycerolkinase (DGK) constitutes an enzyme family that catalyzes conversion of DG to phosphatidic acid. It is therefore regarded as a regulator of the DG signal. Previous studies have revealed the critical role of α and ζ types of DGK in T cell functions. Nevertheless, little is known about the expression patterns of the DGK family in immune cells of various kinds. After examination of the expression profile of DGK isozymes in immune cells that are isolated from human blood, we investigated whether their mRNA expression levels would be changed during an inflammatory reaction. Results showed that DGK isozyme mRNAs are widely expressed in immune cells, except for DGKβ and DGKι. During an inflammatory reaction, DGKε mRNA was increased transiently in the initial phase (20-40 min) of stimulation with both LPS and IL-2 in T cell-derived HUT-102 cells and macrophage-derived RAW264 cells. At the organismal level, an intraperitoneal injection of LPS also induced upregulation of DGKε mRNA in the spleen in a similar,but not identical, manner. These results suggest that DGKε is involved in inflammatory processes of the cellular immune system.
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Affiliation(s)
- Masakazu Yamamoto
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Iida-nishi 2-2-2, Yamagata 990-9585, Japan
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34
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Kweon H, Kim SG, Choi JY. Inhibition of foreign body giant cell formation by 4- hexylresorcinol through suppression of diacylglycerol kinase delta gene expression. Biomaterials 2014; 35:8576-84. [DOI: 10.1016/j.biomaterials.2014.06.050] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Accepted: 06/26/2014] [Indexed: 12/22/2022]
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35
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Garcia LC, Donadío LG, Mann E, Kolusheva S, Kedei N, Lewin NE, Hill CS, Kelsey JS, Yang J, Esch TE, Santos M, Peach ML, Kelley JA, Blumberg PM, Jelinek R, Marquez VE, Comin MJ. Synthesis, biological, and biophysical studies of DAG-indololactones designed as selective activators of RasGRP. Bioorg Med Chem 2014; 22:3123-40. [PMID: 24794745 PMCID: PMC4104769 DOI: 10.1016/j.bmc.2014.04.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 04/05/2014] [Accepted: 04/14/2014] [Indexed: 01/21/2023]
Abstract
The development of selective agents capable of discriminating between protein kinase C (PKC) isoforms and other diacylglycerol (DAG)-responsive C1 domain-containing proteins represents an important challenge. Recent studies have highlighted the role that Ras guanine nucleotide-releasing protein (RasGRP) isoforms play both in immune responses as well as in the development of prostate cancer and melanoma, suggesting that the discovery of selective ligands could have potential therapeutic value. Thus far, the N-methyl-substituted indololactone 1 is the agonist with the highest reported potency and selectivity for RasGRP relative to PKC. Here we present the synthesis, binding studies, cellular assays and biophysical analysis of interactions with model membranes of a family of regioisomers of 1 (compounds 2-5) that differ in the position of the linkage between the indole ring and the lactone moiety. These structural variations were studied to explore the interaction of the active complex (C1 domain-ligand) with cellular membranes, which is believed to be an important factor for selectivity in the activation of DAG-responsive C1 domain containing signaling proteins. All compounds were potent and selective activators of RasGRP when compared to PKCα with selectivities ranging from 6 to 65 fold. However, the parent compound 1 was appreciably more selective than any of the other isomers. In intact cells, modest differences in the patterns of translocation of the C1 domain targets were observed. Biophysical studies using giant vesicles as model membranes did show substantial differences in terms of molecular interactions impacting lipid organization, dynamics and membrane insertion. However, these differences did not yield correspondingly large changes in patterns of biological response, at least for the parameters examined.
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Affiliation(s)
- Lia C Garcia
- Laboratory of Organic Synthesis, Center of Research and Development in Chemistry, National Institute of Industrial Technology, Buenos Aires, Argentina
| | - Lucia Gandolfi Donadío
- Laboratory of Organic Synthesis, Center of Research and Development in Chemistry, National Institute of Industrial Technology, Buenos Aires, Argentina
| | - Ella Mann
- Department of Chemistry, Ben Gurion University, Beer Sheva 84105, Israel
| | - Sofiya Kolusheva
- Department of Chemistry, Ben Gurion University, Beer Sheva 84105, Israel
| | - Noemi Kedei
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Nancy E Lewin
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Colin S Hill
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Jessica S Kelsey
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Jing Yang
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Timothy E Esch
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Marina Santos
- Laboratory of Organic Synthesis, Center of Research and Development in Chemistry, National Institute of Industrial Technology, Buenos Aires, Argentina
| | - Megan L Peach
- Basic Science Program, Leidos Biomedical, Inc., Chemical Biology Laboratory, Frederick National Laboratory for Cancer Research, National Institutes of Health, Frederick, MD 21702, USA
| | - James A Kelley
- Chemical Biology Laboratory, Molecular Discovery Program, Center for Cancer Research, National Cancer Institute at Frederick, National Institutes of Health, Frederick, MD 21702, USA
| | - Peter M Blumberg
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Raz Jelinek
- Department of Chemistry, Ben Gurion University, Beer Sheva 84105, Israel
| | - Victor E Marquez
- Chemical Biology Laboratory, Molecular Discovery Program, Center for Cancer Research, National Cancer Institute at Frederick, National Institutes of Health, Frederick, MD 21702, USA
| | - Maria J Comin
- Laboratory of Organic Synthesis, Center of Research and Development in Chemistry, National Institute of Industrial Technology, Buenos Aires, Argentina.
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36
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Cai K, Lucki NC, Sewer MB. Silencing diacylglycerol kinase-theta expression reduces steroid hormone biosynthesis and cholesterol metabolism in human adrenocortical cells. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1841:552-62. [PMID: 24369117 DOI: 10.1016/j.bbalip.2013.12.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 12/10/2013] [Accepted: 12/13/2013] [Indexed: 11/29/2022]
Abstract
Diacylglycerol kinase theta (DGKθ) plays a pivotal role in regulating adrenocortical steroidogenesis by synthesizing the ligand for the nuclear receptor steroidogenic factor 1 (SF1). In response to activation of the cAMP signaling cascade nuclear DGK activity is rapidly increased, facilitating PA-mediated, SF1-dependent transcription of genes required for cortisol and dehydroepiandrosterone (DHEA) biosynthesis. Based on our previous work identifying DGKθ as the enzyme that produces the agonist for SF1, we generated a tetracycline-inducible H295R stable cell line to express a short hairpin RNA (shRNA) against DGKθ and characterized the effect of silencing DGKθ on adrenocortical gene expression. Genome-wide DNA microarray analysis revealed that silencing DGKθ expression alters the expression of multiple genes, including steroidogenic genes, nuclear receptors and genes involved in sphingolipid, phospholipid and cholesterol metabolism. Interestingly, the expression of sterol regulatory element binding proteins (SREBPs) was also suppressed. Consistent with the suppression of SREBPs, we observed a down-regulation of multiple SREBP target genes, including 3-hydroxy-3-methylglutary coenzyme A reductase (HMG-CoA red) and CYP51, concomitant with a decrease in cellular cholesterol. DGKθ knockdown cells exhibited a reduced capacity to metabolize PA, with a down-regulation of lipin and phospholipase D (PLD) isoforms. In contrast, suppression of DGKθ increased the expression of several genes in the sphingolipid metabolic pathway, including acid ceramidase (ASAH1) and sphingosine kinases (SPHK). In summary, these data demonstrate that DGKθ plays an important role in steroid hormone production in human adrenocortical cells.
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Affiliation(s)
- Kai Cai
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
| | - Natasha C Lucki
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
| | - Marion B Sewer
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA.
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37
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Shin J, Xie D, Zhong XP. MicroRNA-34a enhances T cell activation by targeting diacylglycerol kinase ζ. PLoS One 2013; 8:e77983. [PMID: 24147106 PMCID: PMC3798301 DOI: 10.1371/journal.pone.0077983] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 09/06/2013] [Indexed: 11/18/2022] Open
Abstract
The engagement of the T cell receptor (TCR) induces the generation of diacylglycerol (DAG), an important second messenger activating both the Ras/Erk and PKCθ/NFκB pathways. DAG kinases (DGKs) participate in the metabolism of DAG by converting it to phosphatidic acid. DGKζ has been demonstrated to be able to inhibit DAG signaling following TCR engagement. Deficiency of DGKζ increases the sensitivity of T cells to TCR stimulation, resulting in enhanced T cell activation ex vivo and in vivo. However, the mechanisms that control DGKζ expression are poorly understood. Here we demonstrate that DGKζ mRNA is a direct target of a cellular microRNA miR-34a. The DGKζ transcript is decreased, whereas the primary miR-34a is upregulated upon TCR stimulation. Ectopic miR-34a expression suppresses DGKζ protein expression through the seed match binding to both the 3' untranslated region and coding region of DGKζ mRNA, leading to increased ERK1/2 phosphorylation and surface expression of the T cell activation marker CD69 following TCR cross-linking. In contrast, overexpression of a miR-34a competitive inhibitor increases DGKζ expression and suppresses TCR-mediated T cell activation. Together, our data demonstrate that miR-34a is a negative regulator for DGKζ and may play an important role in regulating T cell activation.
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Affiliation(s)
- Jinwook Shin
- Department of Pediatrics, Division of Allergy and Immunology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Danli Xie
- Department of Pediatrics, Division of Allergy and Immunology, Duke University Medical Center, Durham, North Carolina, United States of America
- School of Laboratory Medicine, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiao-Ping Zhong
- Department of Pediatrics, Division of Allergy and Immunology, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Immunology, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail:
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38
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Sato M, Liu K, Sasaki S, Kunii N, Sakai H, Mizuno H, Saga H, Sakane F. Evaluations of the selectivities of the diacylglycerol kinase inhibitors R59022 and R59949 among diacylglycerol kinase isozymes using a new non-radioactive assay method. Pharmacology 2013; 92:99-107. [PMID: 23949095 DOI: 10.1159/000351849] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 04/30/2013] [Indexed: 11/19/2022]
Abstract
Ten mammalian diacylglycerol kinase (DGK) isozymes (α-κ) have been identified. Recent studies have revealed that DGK isozymes play pivotal roles in a wide variety of pathophysiological functions. Thus, it is important to be able to easily check DGK activity in each pathophysiological event. Moreover, the conventional DGK assay is quite laborious because it requires the use of a radioisotope and thin-layer chromatography including multiple extraction steps. In order to minimize the laborious procedures, we established a non-radioactive, single well, two-step DGK assay system. We demonstrated that, compared to the conventional method, the new assay system has comparable sensitivity and much higher efficiency, and is effective in detecting potential agents with high reliability (Z'-factor = 0.69 ± 0.12; n = 3). Using the newly developed assay, we comprehensively evaluated the DGK isozyme selectivities of commercially available DGK inhibitors, R59022 and R59949, in vitro. We found that among 10 isozymes, R59022 strongly inhibited type I DGKα and moderately attenuated type III DGKε and type V DGKθ, and that R59949 strongly inhibited type I DGK α and γ, and moderately attenuated type II DGK δ and κ.
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Affiliation(s)
- Mayu Sato
- Department of Chemistry, Graduate School of Science, Chiba University, Inage-ku, Chiba, Japan
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39
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Hozumi Y, Watanabe M, Goto K. Signaling cascade of diacylglycerol kinase β in the pituitary intermediate lobe: dopamine D2 receptor/phospholipase Cβ4/diacylglycerol kinase β/protein kinase Cα. J Histochem Cytochem 2013; 58:119-29. [PMID: 19826069 DOI: 10.1369/jhc.2009.954347] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2009] [Accepted: 09/21/2009] [Indexed: 02/05/2023] Open
Abstract
The pituitary gland dynamically changes its hormone output under various pathophysiological conditions. One of the pathways implicated in the regulatory mechanism of this gland is a dopaminergic system that operates the phosphoinositide (PI) cycle to transmit downstream signal through second messengers. We have previously shown that diacylglycerol kinase β (DGKβ) is coexpressed with dopamine D1 and D2 receptors in medium spiny neurons of the striatum, suggesting a plausible implication of DGKβ in dopaminergic transmission. However, it remains elusive whether DGKβ is involved in the dopaminergic system in the pituitary gland. The aim of this study is to investigate the expression and localization of DGK in the pituitary gland, together with the molecular components involved in the PI signaling cascade, including dopamine receptors, phospholipase C (PLC), and a major downstream molecule, protein kinase C (PKC). Here we show that DGKβ and the dopamine D2 receptor are coexpressed in the intermediate lobe and localize to the plasma membrane side by side. In addition, we reveal that PLCβ4 and PKCα are the subtypes expressed in the intermediate lobe among those families. These findings will substantiate and further extend our understanding of the molecular-anatomical pathway of PI signaling and the functional roles of DGK in the pituitary intermediate lobe.
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Affiliation(s)
- Yasukazu Hozumi
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan.
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Cai K, Sewer MB. cAMP-stimulated transcription of DGKθ requires steroidogenic factor 1 and sterol regulatory element binding protein 1. J Lipid Res 2013; 54:2121-2132. [PMID: 23610160 DOI: 10.1194/jlr.m035634] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Diacylglycerol kinase (DGK)θ is a lipid kinase that phosphorylates diacylglycerol to form phosphatidic acid (PA). We have previously shown that PA is a ligand for the nuclear receptor steroidogenic factor 1 (SF1) and that cAMP-stimulated expression of SF1 target genes requires DGKθ. In this study, we sought to investigate the role of cAMP signaling in regulating DGKθ gene expression. Real time RT-PCR and Western blot analysis revealed that dibutyryl cAMP (Bt2cAMP) increased the mRNA and protein expression, respectively, of DGKθ in H295R human adrenocortical cells. SF1 and sterol regulatory element binding protein 1 (SREBP1) increased the transcriptional activity of a reporter plasmid containing 1.5 kb of the DGKθ promoter fused to the luciferase gene. Mutation of putative cAMP responsive sequences abolished SF1- and SREBP-dependent DGKθ reporter gene activation. Consistent with this finding, chromatin immunoprecipitation assay demonstrated that Bt2cAMP signaling increased the recruitment of SF1 and SREBP1 to the DGKθ promoter. Coimmunoprecipitation assay revealed that SF1 and SREBP1 interact, suggesting that the two transcription factors form a complex on the DGKθ promoter. Finally, silencing SF1 and SREBP1 abolished cAMP-stimulated DGKθ expression. Taken together, we demonstrate that SF1 and SREBP1 activate DGKθ transcription in a cAMP-dependent manner in human adrenocortical cells.
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Affiliation(s)
- Kai Cai
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093
| | - Marion B Sewer
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093.
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Dominguez CL, Floyd DH, Xiao A, Mullins GR, Kefas BA, Xin W, Yacur MN, Abounader R, Lee JK, Wilson GM, Harris TE, Purow BW. Diacylglycerol kinase α is a critical signaling node and novel therapeutic target in glioblastoma and other cancers. Cancer Discov 2013; 3:782-97. [PMID: 23558954 DOI: 10.1158/2159-8290.cd-12-0215] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Although diacylglycerol kinase α (DGKα) has been linked to several signaling pathways related to cancer cell biology, it has been neglected as a target for cancer therapy. The attenuation of DGKα activity via DGKα-targeting siRNA and small-molecule inhibitors R59022 and R59949 induced caspase-mediated apoptosis in glioblastoma cells and in other cancers, but lacked toxicity in noncancerous cells. We determined that mTOR and hypoxia-inducible factor-1α (HIF-1α) are key targets of DGKα inhibition, in addition to its regulation of other oncogenes. DGKα regulates mTOR transcription via a unique pathway involving cyclic AMP. Finally, we showed the efficacy of DGKα inhibition with short hairpin RNA or a small-molecule agent in glioblastoma and melanoma xenograft treatment models, with growth delay and decreased vascularity. This study establishes DGKα as a central signaling hub and a promising therapeutic target in the treatment of cancer.
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Affiliation(s)
- Charli L Dominguez
- Division of Neuro-Oncology, Department of Neurology, College of Nursing and Health Professions, University of Southern Indiana, Evansville, Indiana, 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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Sakai H, Sakane F. Recent progress on type II diacylglycerol kinases: the physiological functions of diacylglycerol kinase , and and their involvement in disease. J Biochem 2012; 152:397-406. [DOI: 10.1093/jb/mvs104] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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Takeishi K, Taketomi A, Shirabe K, Toshima T, Motomura T, Ikegami T, Yoshizumi T, Sakane F, Maehara Y. Diacylglycerol kinase alpha enhances hepatocellular carcinoma progression by activation of Ras-Raf-MEK-ERK pathway. J Hepatol 2012; 57:77-83. [PMID: 22425622 DOI: 10.1016/j.jhep.2012.02.026] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 02/02/2012] [Accepted: 02/13/2012] [Indexed: 12/27/2022]
Abstract
BACKGROUND & AIMS Diacylglycerol kinases (DGKs) were recently recognized as key regulators in cell signaling pathways. We investigated whether DGKα is involved in human hepatocellular carcinoma (HCC) progression. METHODS We silenced or overexpressed DGKα in HCC cells and assessed its effect on tumor progression. DGKα expression in 95 surgical samples was analyzed by immunohistochemistry, and the expression status of each sample was correlated with clinicopathological features. RESULTS DGKα was detected in various HCC cell lines but at very low levels in the normal liver. Knockdown of DGKα significantly suppressed cell proliferation and invasion. Overexpression of wild type (WT) DGKα, but not its kinase-dead (KD) mutant, significantly enhanced cell proliferation. DGKα knockdown impaired MEK and ERK phosphorylation, but did not inhibit Ras activation in HCC cells. In a xenograft model, WT DGKα overexpression significantly enhanced tumor growth compared to the control, but KD DGKα mutant had no effect. Immunohistochemical studies showed that DGKα was expressed in cancerous tissue, but not in adjacent non-cancerous hepatocytes. High DGKα expression (≥20%) was associated with high Ki67 expression (p<0.05) and a high rate of HCC recurrence (p=0.033) following surgery. In multivariate analyses, high DGKα expression was an independent factor for determining HCC recurrence after surgery. CONCLUSIONS DGKα is involved in HCC progression by activation of the MAPK pathway. DGKα could be a novel target for HCC therapeutics as well as a prognostic marker.
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Affiliation(s)
- Kazuki Takeishi
- Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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Ishisaka M, Kakefuda K, Oyagi A, Ono Y, Tsuruma K, Shimazawa M, Kitaichi K, Hara H. Diacylglycerol kinase β knockout mice exhibit attention-deficit behavior and an abnormal response on methylphenidate-induced hyperactivity. PLoS One 2012; 7:e37058. [PMID: 22590645 PMCID: PMC3349656 DOI: 10.1371/journal.pone.0037058] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 04/12/2012] [Indexed: 01/22/2023] Open
Abstract
Background Diacylglycerol kinase (DGK) is an enzyme that phosphorylates diacylglycerol to produce phosphatidic acid. DGKβ is one of the subtypes of the DGK family and regulates many intracellular signaling pathways in the central nervous system. Previously, we demonstrated that DGKβ knockout (KO) mice showed various dysfunctions of higher brain function, such as cognitive impairment (with lower spine density), hyperactivity, reduced anxiety, and careless behavior. In the present study, we conducted further tests on DGKβ KO mice in order to investigate the function of DGKβ in the central nervous system, especially in the pathophysiology of attention deficit hyperactivity disorder (ADHD). Methodology/Principal Findings DGKβ KO mice showed attention-deficit behavior in the object-based attention test and it was ameliorated by methylphenidate (MPH, 30 mg/kg, i.p.). In the open field test, DGKβ KO mice displayed a decreased response to the locomotor stimulating effects of MPH (30 mg/kg, i.p.), but showed a similar response to an N-methyl-d-aspartate (NMDA) receptor antagonist, MK-801 (0.3 mg/kg, i.p.), when compared to WT mice. Examination of the phosphorylation of extracellular signal-regulated kinase (ERK), which is involved in regulation of locomotor activity, indicated that ERK1/2 activation induced by MPH treatment was defective in the striatum of DGKβ KO mice. Conclusions/Significance These findings suggest that DGKβ KO mice showed attention-deficit and hyperactive phenotype, similar to ADHD. Furthermore, the hyporesponsiveness of DGKβ KO mice to MPH was due to dysregulation of ERK phosphorylation, and that DGKβ has a pivotal involvement in ERK regulation in the striatum.
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Affiliation(s)
- Mitsue Ishisaka
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, Gifu, Japan
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Prentki M, Madiraju SRM. Glycerolipid/free fatty acid cycle and islet β-cell function in health, obesity and diabetes. Mol Cell Endocrinol 2012; 353:88-100. [PMID: 22108437 DOI: 10.1016/j.mce.2011.11.004] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Revised: 11/07/2011] [Accepted: 11/07/2011] [Indexed: 12/16/2022]
Abstract
Pancreatic β-cells secrete insulin in response to fluctuations in blood fuel concentrations, in particular glucose and fatty acids. However, chronic fuel surfeit can overwhelm the metabolic, signaling and secretory capacity of the β-cell leading to its dysfunction and death - often referred to as glucolipotoxicity. In β-cells and many other cells, glucose and lipid metabolic pathways converge into a glycerolipid/free fatty acid (GL/FFA) cycle, which is driven by the substrates, glycerol-3-phosphate and fatty acyl-CoA, derived from glucose and fatty acids, respectively. Although the overall operation of GL/FFA cycle, consisting of lipolysis and lipogenesis, is "futile" in terms of energy expenditure, this metabolic cycle likely plays an indispensable role for various β-cell functions, in particular insulin secretion and excess fuel detoxification. In this review, we discuss the significance of GL/FFA cycle in the β-cell, its regulation and role in generating essential metabolic signals that participate in the lipid amplification arm of glucose stimulated insulin secretion and in β-cell growth. We propose the novel concept that the lipolytic segment of GL/FFA cycle is instrumental in producing signals for insulin secretion, whereas, the lipogenic segment generates signals relevant for β-cell survival/death and growth/proliferation.
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Affiliation(s)
- Marc Prentki
- Departments of Nutrition and Biochemistry, University of Montreal, Montreal Diabetes Research Center, CR-CHUM, Technopôle Angus, 2901, Montreal, Canada QC H1W 4A4.
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Hozumi Y, Goto K. Diacylglycerol kinase β in neurons: functional implications at the synapse and in disease. Adv Biol Regul 2012; 52:315-25. [PMID: 22781745 DOI: 10.1016/j.jbior.2012.03.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Accepted: 03/23/2012] [Indexed: 11/18/2022]
Abstract
Phosphoinositide cycle plays a pivotal role in neuronal signal transduction. In this cycle, diacylglycerol kinase (DGK) phosphorylates diacylglycerol (DG) to yield phosphatidic acid (PA). DG and PA acts as important second messengers that regulate distinct cascade of cellular events. Previous studies have disclosed that DGK consists of a family of isozymes that differ in their structure, enzymatic property, gene expression, subcellular localization, and binding partner. Intriguingly, most if not all DGK isozymes are abundantly expressed in the brain, suggesting important roles of this enzyme family in brain function. Of DGKs, DGKβ was the first enzyme identified as being expressed in a neuronal population in the brain. This review focuses on recent findings of DGKβ at the molecular, cellular, and organismal levels together with pathological implications in brain function and disease.
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Affiliation(s)
- Yasukazu Hozumi
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Iida-nishi 2-2-2, Yamagata 990-9585, Japan.
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Han S, Bahmanyar S, Zhang P, Grishin N, Oegema K, Crooke R, Graham M, Reue K, Dixon JE, Goodman JM. Nuclear envelope phosphatase 1-regulatory subunit 1 (formerly TMEM188) is the metazoan Spo7p ortholog and functions in the lipin activation pathway. J Biol Chem 2012; 287:3123-37. [PMID: 22134922 PMCID: PMC3283218 DOI: 10.1074/jbc.m111.324350] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Indexed: 11/06/2022] Open
Abstract
Lipin-1 catalyzes the formation of diacylglycerol from phosphatidic acid. Lipin-1 mutations cause lipodystrophy in mice and acute myopathy in humans. It is heavily phosphorylated, and the yeast ortholog Pah1p becomes membrane-associated and active upon dephosphorylation by the Nem1p-Spo7p membrane complex. A mammalian ortholog of Nem1p is the C-terminal domain nuclear envelope phosphatase 1 (CTDNEP1, formerly "dullard"), but its Spo7p-like partner is unknown, and the need for its existence is debated. Here, we identify the metazoan ortholog of Spo7p, TMEM188, renamed nuclear envelope phosphatase 1-regulatory subunit 1 (NEP1-R1). CTDNEP1 and NEP1-R1 together complement a nem1Δspo7Δ strain to block endoplasmic reticulum proliferation and restore triacylglycerol levels and lipid droplet number. The two human orthologs are in a complex in cells, and the amount of CTDNEP1 is increased in the presence of NEP1-R1. In the Caenorhabditis elegans embryo, expression of nematode CTDNEP1 and NEP1-R1, as well as lipin-1, is required for normal nuclear membrane breakdown after zygote formation. The expression pattern of NEP1-R1 and CTDNEP1 in human and mouse tissues closely mirrors that of lipin-1. CTDNEP1 can dephosphorylate lipins-1a, -1b, and -2 in human cells only in the presence of NEP1-R1. The nuclear fraction of lipin-1b is increased when CTDNEP1 and NEP1-R1 are co-expressed. Therefore, NEP1-R1 is functionally conserved from yeast to humans and functions in the lipin activation pathway.
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Affiliation(s)
| | - Shirin Bahmanyar
- the Ludwig Institute for Cancer Research, Department of Cell and Molecular Medicine, and
| | - Peixiang Zhang
- the Department of Human Genetics, David Geffen School of Medicine, UCLA, Los Angeles, California 90095, and
| | - Nick Grishin
- Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Karen Oegema
- the Ludwig Institute for Cancer Research, Department of Cell and Molecular Medicine, and
| | | | - Mark Graham
- ISIS Pharmaceuticals, Inc., Carlsbad, California 92008
| | - Karen Reue
- the Department of Human Genetics, David Geffen School of Medicine, UCLA, Los Angeles, California 90095, and
| | - Jack E. Dixon
- Department of Pharmacology, School of Medicine, University of California at San Diego, La Jolla, California 92093
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Lee D, Kim J, Beste MT, Koretzky GA, Hammer DA. Diacylglycerol kinase zeta negatively regulates CXCR4-stimulated T lymphocyte firm arrest to ICAM-1 under shear flow. Integr Biol (Camb) 2012; 4:606-14. [DOI: 10.1039/c2ib00002d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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