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Hernandez-Lara MA, Richard J, Deshpande DA. Diacylglycerol kinase is a keystone regulator of signaling relevant to the pathophysiology of asthma. Am J Physiol Lung Cell Mol Physiol 2024; 327:L3-L18. [PMID: 38742284 DOI: 10.1152/ajplung.00091.2024] [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: 03/08/2024] [Revised: 04/05/2024] [Accepted: 04/23/2024] [Indexed: 05/16/2024] Open
Abstract
Signal transduction by G protein-coupled receptors (GPCRs), receptor tyrosine kinases (RTKs) and immunoreceptors converge at the activation of phospholipase C (PLC) for the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) into inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG). This is a point for second-messenger bifurcation where DAG via protein kinase C (PKC) and IP3 via calcium activate distinct protein targets and regulate cellular functions. IP3 signaling is regulated by multiple calcium influx and efflux proteins involved in calcium homeostasis. A family of lipid kinases belonging to DAG kinases (DGKs) converts DAG to phosphatidic acid (PA), negatively regulating DAG signaling and pathophysiological functions. PA, through a series of biochemical reactions, is recycled to produce new molecules of PIP2. Therefore, DGKs act as a central switch in terminating DAG signaling and resynthesis of membrane phospholipids precursor. Interestingly, calcium and PKC regulate the activation of α and ζ isoforms of DGK that are predominantly expressed in airway and immune cells. Thus, DGK forms a feedback and feedforward control point and plays a crucial role in fine-tuning phospholipid stoichiometry, signaling, and functions. In this review, we discuss the previously underappreciated complex and intriguing DAG/DGK-driven mechanisms in regulating cellular functions associated with asthma, such as contraction and proliferation of airway smooth muscle (ASM) cells and inflammatory activation of immune cells. We highlight the benefits of manipulating DGK activity in mitigating salient features of asthma pathophysiology and shed light on DGK as a molecule of interest for heterogeneous diseases such as asthma.
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Affiliation(s)
- Miguel A Hernandez-Lara
- Department of Medicine, Center for Translational Medicine, Jane & Leonard Korman Respiratory Institute, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States
| | - Joshua Richard
- Department of Medicine, Center for Translational Medicine, Jane & Leonard Korman Respiratory Institute, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States
| | - Deepak A Deshpande
- Department of Medicine, Center for Translational Medicine, Jane & Leonard Korman Respiratory Institute, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States
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Yang W, Feng R, Peng G, Wang Z, Cen M, Jing Y, Feng W, Long T, Liu Y, Li Z, Huang K, Chang G. Glycoursodeoxycholic Acid Alleviates Arterial Thrombosis via Suppressing Diacylglycerol Kinases Activity in Platelet. Arterioscler Thromb Vasc Biol 2024; 44:1283-1301. [PMID: 38572646 DOI: 10.1161/atvbaha.124.320728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 03/19/2024] [Indexed: 04/05/2024]
Abstract
BACKGROUND Glycoursodeoxycholic acid (GUDCA) has been acknowledged for its ability to regulate lipid homeostasis and provide benefits for various metabolic disorders. However, the impact of GUDCA on arterial thrombotic events remains unexplored. The objective of this study is to examine the effects of GUDCA on thrombogenesis and elucidate its underlying mechanisms. METHODS Plasma samples from patients with arterial thrombotic events and diet-induced obese mice were collected to determine the GUDCA concentrations using mass spectrometry. Multiple in vivo murine thrombosis models and in vitro platelet functional assays were conducted to comprehensively evaluate the antithrombotic effects of GUDCA. Moreover, lipidomic analysis was performed to identify the alterations of intraplatelet lipid components following GUDCA treatment. RESULTS Plasma GUDCA level was significantly decreased in patients with arterial thrombotic events and negatively correlated with thrombotic propensity in diet-induced obese mice. GUDCA exhibited prominent suppressing effects on platelet reactivity as evidenced by the attenuation of platelet activation, secretion, aggregation, spreading, and retraction (P<0.05). In vivo, GUDCA administration robustly alleviated thrombogenesis (P<0.05) without affecting hemostasis. Mechanistically, GUDCA inhibited DGK (diacylglycerol kinase) activity, leading to the downregulation of the phosphatidic acid-mediated signaling pathway. Conversely, phosphatidic acid supplementation was sufficient to abolish the antithrombotic effects of GUDCA. More importantly, long-term oral administration of GUDCA normalized the enhanced DGK activity, thereby remarkably alleviating the platelet hyperreactivity as well as the heightened thrombotic tendency in diet-induced obese mice (P<0.05). CONCLUSIONS Our study implicated that GUDCA reduces platelet hyperreactivity and improves thrombotic propensity by inhibiting DGKs activity, which is a potentially effective prophylactic approach and promising therapeutic agent for arterial thrombotic events.
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Affiliation(s)
- Wenchao Yang
- Division of Vascular Surgery, National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China (W.Y., R.F., G.P., Z.W., Y.J., W.F., T.L., Y.L., Z.L, K.H., G.C.)
| | - Ruijia Feng
- Division of Vascular Surgery, National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China (W.Y., R.F., G.P., Z.W., Y.J., W.F., T.L., Y.L., Z.L, K.H., G.C.)
| | - Guiyan Peng
- Division of Vascular Surgery, National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China (W.Y., R.F., G.P., Z.W., Y.J., W.F., T.L., Y.L., Z.L, K.H., G.C.)
| | - Zhecun Wang
- Division of Vascular Surgery, National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China (W.Y., R.F., G.P., Z.W., Y.J., W.F., T.L., Y.L., Z.L, K.H., G.C.)
| | - Meifeng Cen
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Guangdong-Hong Kong Joint Laboratory for RNA Medicine, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, China (M.C.)
| | - Yexiang Jing
- Division of Vascular Surgery, National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China (W.Y., R.F., G.P., Z.W., Y.J., W.F., T.L., Y.L., Z.L, K.H., G.C.)
| | - Weiqi Feng
- Division of Vascular Surgery, National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China (W.Y., R.F., G.P., Z.W., Y.J., W.F., T.L., Y.L., Z.L, K.H., G.C.)
| | - Ting Long
- Division of Vascular Surgery, National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China (W.Y., R.F., G.P., Z.W., Y.J., W.F., T.L., Y.L., Z.L, K.H., G.C.)
| | - Yunchong Liu
- Division of Vascular Surgery, National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China (W.Y., R.F., G.P., Z.W., Y.J., W.F., T.L., Y.L., Z.L, K.H., G.C.)
| | - Zilun Li
- Division of Vascular Surgery, National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China (W.Y., R.F., G.P., Z.W., Y.J., W.F., T.L., Y.L., Z.L, K.H., G.C.)
| | - Kan Huang
- Division of Vascular Surgery, National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China (W.Y., R.F., G.P., Z.W., Y.J., W.F., T.L., Y.L., Z.L, K.H., G.C.)
| | - Guangqi Chang
- Division of Vascular Surgery, National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China (W.Y., R.F., G.P., Z.W., Y.J., W.F., T.L., Y.L., Z.L, K.H., G.C.)
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Seino K, Nakano T, Tanaka T, Hozumi Y, Topham MK, Goto K, Iseki K. Ablation of DGKα facilitates α-smooth muscle actin expression via the Smad and PKCδ signaling pathways during the acute phase of CCl 4 -induced hepatic injury. FEBS Open Bio 2024; 14:300-308. [PMID: 38105414 PMCID: PMC10839370 DOI: 10.1002/2211-5463.13749] [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: 05/15/2023] [Revised: 10/31/2023] [Accepted: 12/12/2023] [Indexed: 12/19/2023] Open
Abstract
Expression of α-smooth muscle actin (αSMA) is constitutive in vascular smooth muscle cells, but is induced in nonmuscle cells such as hepatic stellate cells (HSCs). HSCs play important roles in both physiological homeostasis and pathological response. HSC activation is characterized by αSMA expression, which is regulated by the TGFβ-induced Smad pathway. Recently, protein kinase C (PKC) was identified to regulate αSMA expression. Diacylglycerol kinase (DGK) metabolizes a second-messenger DG, thereby controlling components of DG-mediated signaling, such as PKC. In the present study we aimed to investigate the putative role of DGKα in αSMA expression. Use of a cellular model indicated that the DGK inhibitor R59949 promotes αSMA expression and PKCδ phosphorylation. It also facilitates Smad2 phosphorylation after 30 min of TGFβ stimulation. Furthermore, immunocytochemical analysis revealed that DGK inhibitor pretreatment without TGFβ stimulation engenders αSMA expression in a granular pattern, whereas DGK inhibitor pretreatment plus TGFβ stimulation significantly induces αSMA incorporation in stress fibers. Through animal model experiments, we observed that DGKα-knockout mice exhibit increased expression of αSMA in the liver after 48 h of carbon tetrachloride injection, together with enhanced phosphorylation levels of Smad2 and PKCδ. Together, these findings suggest that DGKα negatively regulates αSMA expression by acting on the Smad and PKCδ signaling pathways, which differentially regulate stress fiber incorporation and protein expression of αSMA, respectively.
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Affiliation(s)
- Keiko Seino
- Department of Anatomy and Cell BiologyYamagata University School of MedicineJapan
| | - Tomoyuki Nakano
- Department of Anatomy and Cell BiologyYamagata University School of MedicineJapan
| | - Toshiaki Tanaka
- Department of Anatomy and Cell BiologyYamagata University School of MedicineJapan
| | - Yasukazu Hozumi
- Department of Cell Biology and MorphologyAkita University Graduate School of MedicineJapan
| | | | - Kaoru Goto
- Department of Anatomy and Cell BiologyYamagata University School of MedicineJapan
| | - Ken Iseki
- Department of Emergency and Critical Care Medicine, School of MedicineFukushima Medical UniversityFukushimaJapan
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Habbas K, Cakil O, Zámbó B, Tabet R, Riet F, Dembele D, Mandel JL, Hocquemiller M, Laufer R, Piguet F, Moine H. AAV-delivered diacylglycerol kinase DGKk achieves long-term rescue of fragile X syndrome mouse model. EMBO Mol Med 2022; 14:e14649. [PMID: 35373916 PMCID: PMC9081908 DOI: 10.15252/emmm.202114649] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 03/10/2022] [Accepted: 03/11/2022] [Indexed: 11/09/2022] Open
Abstract
Fragile X syndrome (FXS) is the most frequent form of familial intellectual disability. FXS results from the lack of the RNA-binding protein FMRP and is associated with the deregulation of signaling pathways downstream of mGluRI receptors and upstream of mRNA translation. We previously found that diacylglycerol kinase kappa (DGKk), a main mRNA target of FMRP in cortical neurons and a master regulator of lipid signaling, is downregulated in the absence of FMRP in the brain of Fmr1-KO mouse model. Here we show that adeno-associated viral vector delivery of a modified and FMRP-independent form of DGKk corrects abnormal cerebral diacylglycerol/phosphatidic acid homeostasis and FXS-relevant behavioral phenotypes in the Fmr1-KO mouse. Our data suggest that DGKk is an important factor in FXS pathogenesis and provide preclinical proof of concept that its replacement could be a viable therapeutic strategy in FXS.
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Affiliation(s)
- Karima Habbas
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Département de Médecine Translationelle et Neurogénétique, Centre National de la Recherche Scientifique (CNRS UMR7104), Institut National de la Santé et de la Recherche Médicale (INSERM U1258), Université de Strasbourg, Illkirch, France
| | - Oktay Cakil
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Département de Médecine Translationelle et Neurogénétique, Centre National de la Recherche Scientifique (CNRS UMR7104), Institut National de la Santé et de la Recherche Médicale (INSERM U1258), Université de Strasbourg, Illkirch, France
| | - Boglárka Zámbó
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Département de Médecine Translationelle et Neurogénétique, Centre National de la Recherche Scientifique (CNRS UMR7104), Institut National de la Santé et de la Recherche Médicale (INSERM U1258), Université de Strasbourg, Illkirch, France
| | - Ricardos Tabet
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Département de Médecine Translationelle et Neurogénétique, Centre National de la Recherche Scientifique (CNRS UMR7104), Institut National de la Santé et de la Recherche Médicale (INSERM U1258), Université de Strasbourg, Illkirch, France
| | - Fabrice Riet
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), PHENOMIN-ICS, Centre National de la Recherche Scientifique (CNRS UMR7104), Institut National de la Santé et de la Recherche Médicale (INSERM U1258), Université de Strasbourg, Illkirch, France
| | - Doulaye Dembele
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Département de Médecine Translationelle et Neurogénétique, Centre National de la Recherche Scientifique (CNRS UMR7104), Institut National de la Santé et de la Recherche Médicale (INSERM U1258), Université de Strasbourg, Illkirch, France
| | - Jean-Louis Mandel
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Département de Médecine Translationelle et Neurogénétique, Centre National de la Recherche Scientifique (CNRS UMR7104), Institut National de la Santé et de la Recherche Médicale (INSERM U1258), Université de Strasbourg, Illkirch, France
| | | | | | - Françoise Piguet
- NeuroGenCell, INSERM U1127, Paris Brain Institute (ICM), Sorbonne University, CNRS, AP-HP, University Hospital Pitié-Salpêtrière, Paris, France
| | - Hervé Moine
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Département de Médecine Translationelle et Neurogénétique, Centre National de la Recherche Scientifique (CNRS UMR7104), Institut National de la Santé et de la Recherche Médicale (INSERM U1258), Université de Strasbourg, Illkirch, France
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5
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Fu L, Deng R, Huang Y, Yang X, Jiang N, Zhou J, Lin C, Chen S, Wu L, Cui Q, Yun J. DGKA interacts with SRC/FAK to promote the metastasis of non-small cell lung cancer. Cancer Lett 2022; 532:215585. [PMID: 35131384 DOI: 10.1016/j.canlet.2022.215585] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 01/31/2022] [Accepted: 02/02/2022] [Indexed: 12/25/2022]
Abstract
Metastasis is responsible for the high mortality rate of lung cancer, but its underlying molecular mechanisms are poorly understood. Here, we demonstrated that the expression of diacylglycerol kinase alpha (DGKA) was elevated in the metastatic lesions of non-small cell lung cancer (NSCLC) and correlated with poor survival. Mechanistic studies revealed a direct physical interaction as well as a mutual regulation among DGKA, proto-oncogene tyrosine-protein kinase Src (SRC), and focal adhesion kinase 1 (FAK) proteins. The C-terminal domain of DGKA was responsible for the SRC SH3 domain binding, while the catalytic domain of DGKA interacted with the FREM domain of FAK. DGKA phosphorylated the SRC protein at Tyr416 and the FAK protein at Tyr397 to form and activate the DGKA/SRC/FAK complex, thus initiating the downstream WNT/β-catenin and VEGF signaling pathways, promoting epithelial-mesenchymal transition (EMT) and angiogenesis, and resulting in the metastasis of NSCLC. DGKA knockdown inhibited the invasive phenotype of NSCLC cells in vitro. Pharmacologic ablation of DGKA inhibited the metastasis of NSCLC cells in vivo, and this was reversed by the overexpression of DGKA. These results suggested that DGKA was a potential prognostic biomarker as well as a promising therapeutic target for NSCLC, especially when there was lymphatic or distant metastasis.
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Affiliation(s)
- Lingyi Fu
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China; Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou, China.
| | - Ru Deng
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China; Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou, China.
| | - Yuhua Huang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China; Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou, China.
| | - Xia Yang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China; Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou, China.
| | - Neng Jiang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China; Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou, China.
| | - Jing Zhou
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China; Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou, China.
| | - Censhan Lin
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China; Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou, China.
| | - Shilu Chen
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China; Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou, China.
| | - Liyan Wu
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China; Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou, China.
| | - Qian Cui
- Department of Pathology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.
| | - Jingping Yun
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China; Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou, China.
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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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Sakane F, Hoshino F, Ebina M, Sakai H, Takahashi D. The Roles of Diacylglycerol Kinase α in Cancer Cell Proliferation and Apoptosis. Cancers (Basel) 2021; 13:cancers13205190. [PMID: 34680338 PMCID: PMC8534027 DOI: 10.3390/cancers13205190] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 10/14/2021] [Accepted: 10/14/2021] [Indexed: 02/02/2023] Open
Abstract
Simple Summary Diacylglycerol (DG) kinase (DGK) phosphorylates DG to generate phosphatidic acid (PA). DGKα is highly expressed in several refractory cancer cells, including melanoma, hepatocellular carcinoma, and glioblastoma cells, attenuates apoptosis, and promotes proliferation. In cancer cells, PA produced by DGKα plays an important role in proliferation/antiapoptosis. In addition to cancer cells, DGKα is highly abundant in T cells and induces a nonresponsive state (anergy), representing the main mechanism by which advanced cancers avoid immune action. In T cells, DGKα induces anergy through DG consumption. Therefore, a DGKα-specific inhibitor is expected to be a dual effective anticancer treatment that inhibits cancer cell proliferation and simultaneously activates T cell function. Moreover, the inhibition of DGKα synergistically enhances the anticancer effects of programmed cell death-1/programmed cell death ligand 1 blockade. Taken together, DGKα inhibition provides a promising new treatment strategy for refractory cancers. Abstract Diacylglycerol (DG) kinase (DGK) phosphorylates DG to generate phosphatidic acid (PA). The α isozyme is activated by Ca2+ through its EF-hand motifs and tyrosine phosphorylation. DGKα is highly expressed in several refractory cancer cells including melanoma, hepatocellular carcinoma, and glioblastoma cells. In melanoma cells, DGKα is an antiapoptotic factor that activates nuclear factor-κB (NF-κB) through the atypical protein kinase C (PKC) ζ-mediated phosphorylation of NF-κB. DGKα acts as an enhancer of proliferative activity through the Raf–MEK–ERK pathway and consequently exacerbates hepatocellular carcinoma progression. In glioblastoma and melanoma cells, DGKα attenuates apoptosis by enhancing the phosphodiesterase (PDE)-4A1–mammalian target of the rapamycin pathway. As PA activates PKCζ, Raf, and PDE, it is likely that PA generated by DGKα plays an important role in the proliferation/antiapoptosis of cancer cells. In addition to cancer cells, DGKα is highly abundant in T cells and induces a nonresponsive state (anergy), which represents the main mechanism by which advanced cancers escape immune action. In T cells, DGKα attenuates the activity of Ras-guanyl nucleotide-releasing protein, which is activated by DG and avoids anergy through DG consumption. Therefore, a DGKα-specific inhibitor is expected to be a dual effective anticancer treatment that inhibits cancer cell proliferation and simultaneously enhances T cell functions. Moreover, the inhibition of DGKα synergistically enhances the anticancer effects of programmed cell death-1/programmed cell death ligand 1 blockade. Taken together, DGKα inhibition provides a promising new treatment strategy for refractory cancers.
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Affiliation(s)
- Fumio Sakane
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba 263-8522, Japan; (F.H.); (M.E.)
- Correspondence: ; Tel.: +81-43-290-3695
| | - Fumi Hoshino
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba 263-8522, Japan; (F.H.); (M.E.)
| | - Masayuki Ebina
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba 263-8522, Japan; (F.H.); (M.E.)
| | - Hiromichi Sakai
- Department of Biosignaling and Radioisotope Experiment, Interdisciplinary Center for Science Research, Organization for Research and Academic Information, Shimane University, Izumo 693-8501, Japan;
| | - Daisuke Takahashi
- Department of Pharmaceutical Health Care and Sciences, Kyushu University, Fukuoka 812-8582, Japan;
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Diacylglycerol Kinase alpha in X Linked Lymphoproliferative Disease Type 1. Int J Mol Sci 2021; 22:ijms22115816. [PMID: 34072296 PMCID: PMC8198409 DOI: 10.3390/ijms22115816] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 05/26/2021] [Accepted: 05/26/2021] [Indexed: 12/31/2022] Open
Abstract
Diacylglycerol kinases are intracellular enzymes that control the balance between the secondary messengers diacylglycerol and phosphatidic acid. DGKα and DGKζ are the prominent isoforms that restrain the intensity of T cell receptor signalling by metabolizing PLCγ generated diacylglycerol. Thus, their activity must be tightly controlled to grant cellular homeostasis and refine immune responses. DGKα is specifically inhibited by strong T cell activating signals to allow for full diacylglycerol signalling which mediates T cell response. In X-linked lymphoproliferative disease 1, deficiency of the adaptor protein SAP results in altered T cell receptor signalling, due in part to persistent DGKα activity. This activity constrains diacylglycerol levels, attenuating downstream pathways such as PKCθ and Ras/MAPK and decreasing T cell restimulation induced cell death. This is a form of apoptosis triggered by prolonged T cell activation that is indeed defective in CD8+ cells of X-linked lymphoproliferative disease type 1 patients. Accordingly, inhibition or downregulation of DGKα activity restores in vitro a correct diacylglycerol dependent signal transduction, cytokines production and restimulation induced apoptosis. In animal disease models, DGKα inhibitors limit CD8+ expansion and immune-mediated tissue damage, suggesting the possibility of using inhibitors of diacylglycerol kinase as a new therapeutic approach.
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9
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Diacylglycerol kinase α inhibition cooperates with PD-1-targeted therapies to restore the T cell activation program. Cancer Immunol Immunother 2021; 70:3277-3289. [PMID: 33837851 DOI: 10.1007/s00262-021-02924-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 03/22/2021] [Indexed: 12/19/2022]
Abstract
BACKGROUND Antibody-based therapies blocking the programmed cell death-1/ligand-1 (PD-1/PD-L1) axis have provided unprecedent clinical success in cancer treatment. Acquired resistance, however, frequently occurs, commonly associated with the upregulation of additional inhibitory molecules. Diacylglycerol kinase (DGK) α limits the extent of Ras activation in response to antigen recognition, and its upregulation facilitates hypofunctional, exhausted T cell states. Pharmacological DGKα targeting restores cytotoxic function of chimeric antigen receptor and CD8+ T cells isolated from solid tumors, suggesting a mechanism to reverse T cell exhausted phenotypes. Nevertheless, the contribution of DGKα downstream of the PD-1/PD-L1 inhibitory axis in human T cells and the consequences of combining DGKα and anti-PD-1/PD-L1 inhibitors are still unresolved relevant issues. MATERIALS AND METHODS We used a human triple parameter reporter cell line to investigate DGKα contribution to the PD-1/PD-L1 inhibitory pathway. We also addressed the impact of deleting DGKα expression in the growth dynamics and systemic tumor-derived effects of a PD-1-related tumor model, the MC38 colon adenocarcinoma. RESULTS We identify DGKα as a contributor to the PD-1/PD-L1 axis that strongly limits the Ras/ERK/AP-1 pathway. DGKα function reinforces exhausted T cell phenotypes ultimately promoting tumor growth and generalized immunosuppression. Pharmacological DGKα inhibition selectively enhances AP-1 transcription and, importantly, cooperates with antibodies blocking the PD-1/PD-L1 interrelation. CONCLUSIONS Our results indicate that DGKα inhibition could provide an important mechanism to revert exhausted T lymphocyte phenotypes and thus favor proper anti-tumor T cell responses. The cooperative effect observed after PD-1/PD-L1 and DGKα blockade offers a promising strategy to improve the efficacy of immunotherapy in the treatment of cancer.
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10
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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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11
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Kambayashi T, Deshpande DA. The role of diacylglycerol kinases in allergic airway disease. Curr Opin Pharmacol 2020; 51:50-58. [PMID: 32836013 DOI: 10.1016/j.coph.2020.07.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 07/24/2020] [Accepted: 07/27/2020] [Indexed: 12/28/2022]
Abstract
Asthma is an obstructive inflammatory airway disease. Airway obstruction is mediated by hyperresponsive airway smooth muscle cell contraction, which is induced and compounded by inflammation caused by T lymphocytes. One important signal transduction pathway that is involved in the activation of these cell types involves the generation of a lipid second messenger known as diacylglycerol (DAG). DAG levels are controlled in cells by a negative regulator known as DAG kinase (DGK). In this review, we discuss how the DAG signaling pathway attenuates the pathological function of immune cells and airway smooth muscle cells in allergic airway disease and asthma. Furthermore, we discuss how the enhancement of the DAG signaling pathway through the inhibition of DGK may represent a novel therapeutic strategy for these diseases.
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Affiliation(s)
- Taku Kambayashi
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
| | - Deepak A Deshpande
- Center for Translational Medicine, Jane and Leonard Korman Lung Center, Thomas Jefferson University, Philadelphia, PA, USA.
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12
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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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13
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Liu CS, Schmezer P, Popanda O. Diacylglycerol Kinase Alpha in Radiation-Induced Fibrosis: Potential as a Predictive Marker or Therapeutic Target. Front Oncol 2020; 10:737. [PMID: 32477950 PMCID: PMC7235333 DOI: 10.3389/fonc.2020.00737] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 04/17/2020] [Indexed: 12/14/2022] Open
Abstract
Radiotherapy is an efficient tool in cancer treatment, but it brings along the risk of side effects such as fibrosis in the irradiated healthy tissue thus limiting tumor control and impairing quality of life of cancer survivors. Knowledge on radiation-related fibrosis risk and therapeutic options is still limited and requires further research. Recent studies demonstrated that epigenetic regulation of diacylglycerol kinase alpha (DGKA) is associated with radiation-induced fibrosis. However, the specific mechanisms are still unknown. In this review, we scrutinized the role of DGKA in the radiation response and in further cellular functions to show the potential of DGKA as a predictive marker or a novel target in fibrosis treatment. DGKA was reported to participate in immune response, lipid signaling, exosome production, and migration as well as cell proliferation, all processes which are suggested to be critical steps in fibrogenesis. Most of these functions are based on the conversion of diacylglycerol (DAG) to phosphatidic acid (PA) at plasma membranes, but DGKA might have also other, yet not well-known functions in the nucleus. Current evidence summarized here underlines that DGKA activation may play a central role in fibrosis formation post-irradiation and shows a potential of direct DGKA inhibitors or epigenetic modulators to attenuate pro-fibrotic reactions, thus providing novel therapeutic choices.
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Affiliation(s)
- Chun-Shan Liu
- Division of Cancer Epigenomics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Peter Schmezer
- Division of Cancer Epigenomics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Odilia Popanda
- Division of Cancer Epigenomics, German Cancer Research Center (DKFZ), Heidelberg, Germany
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14
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Liu L, Yudin Y, Rohacs T. Diacylglycerol kinases regulate TRPV1 channel activity. J Biol Chem 2020; 295:8174-8185. [PMID: 32345612 DOI: 10.1074/jbc.ra119.012505] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 04/24/2020] [Indexed: 11/06/2022] Open
Abstract
The transient receptor potential vanilloid 1 (TRPV1) channel is activated by heat and by capsaicin, the pungent compound in chili peppers. Calcium influx through TRPV1 has been shown to activate a calcium-sensitive phospholipase C (PLC) enzyme and to lead to a robust decrease in phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] levels, which is a major contributor to channel desensitization. Diacylglycerol (DAG), the product of the PLC-catalyzed PI(4,5)P2 hydrolysis, activates protein kinase C (PKC). PKC is known to potentiate TRPV1 activity during activation of G protein-coupled receptors, but it is not known whether DAG modulates TRPV1 during desensitization. We found here that inhibition of diacylglycerol kinase (DAGK) enzymes reduces desensitization of native TRPV1 in dorsal root ganglion neurons as well as of recombinant TRPV1 expressed in HEK293 cells. The effect of DAGK inhibition was eliminated by mutating two PKC-targeted phosphorylation sites, Ser-502 and Ser-800, indicating involvement of PKC. TRPV1 activation induced only a small and transient increase in DAG levels, unlike the robust and more sustained increase induced by muscarinic receptor activation. DAGK inhibition substantially increased the DAG signal evoked by TRPV1 activation but not that evoked by M1 muscarinic receptor activation. Our results show that Ca2+ influx through TRPV1 activates PLC and DAGK enzymes and that the latter limits formation of DAG and negatively regulates TRPV1 channel activity. Our findings uncover a role of DAGK in ion channel regulation.
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Affiliation(s)
- Luyu Liu
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Yevgen Yudin
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Tibor Rohacs
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers New Jersey Medical School, Newark, New Jersey, USA
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15
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Li J, Pan C, Boese AC, Kang J, Umano AD, Magliocca KR, Yang W, Zhang Y, Lonial S, Jin L, Kang S. DGKA Provides Platinum Resistance in Ovarian Cancer Through Activation of c-JUN-WEE1 Signaling. Clin Cancer Res 2020; 26:3843-3855. [PMID: 32341033 DOI: 10.1158/1078-0432.ccr-19-3790] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 03/17/2020] [Accepted: 04/22/2020] [Indexed: 02/07/2023]
Abstract
PURPOSE Although platinum compounds are the first-line treatment for ovarian cancer, the majority of patients relapse and develop resistance to treatment. However, the mechanism underlying resistance is unclear. The goal of our study is to decipher the mechanism by which a metabolic kinase, diacylglycerol kinase alpha (DGKA), confers platinum resistance in ovarian cancer. EXPERIMENTAL DESIGN Metabolic kinase RNAi synthetic lethal screening was used to identify a cisplatin resistance driver in ovarian cancer. DGKA variants were used to demonstrate the need for DGKA activity in cisplatin resistance. Phospho-proteomic and genomic screens were performed to identify downstream effectors of DGKA. Therapeutic efficacy of targeting DGKA was confirmed and clinical relevance of DGKA signaling was validated using ovarian cancer patient-derived tumors that had different responses to platinum-based therapy. RESULTS We found that platinum resistance was mediated by DGKA and its product, phosphatidic acid (PA), in ovarian cancer. Proteomic and genomic screens revealed that DGKA activates the transcription factor c-JUN and consequently enhances expression of a cell-cycle regulator, WEE1. Mechanistically, PA facilitates c-JUN N-terminal kinase recruitment to c-JUN and its nuclear localization, leading to c-JUN activation upon cisplatin exposure. Pharmacologic inhibition of DGKA sensitized ovarian cancer cells to cisplatin treatment and DGKA-c-JUN-WEE1 signaling positively correlated with platinum resistance in tumors derived from patients with ovarian cancer. CONCLUSIONS Our study demonstrates how the DGKA-derived lipid messenger, PA, contributes to cisplatin resistance by intertwining with kinase and transcription networks, and provides preclinical evidence for targeting DGKA as a new strategy in ovarian cancer treatment to battle cisplatin resistance.
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Affiliation(s)
- Jie Li
- Department of Hematology and Medical Oncology, Winship Cancer Institute, Emory University School of Medicine, Atlanta, Georgia.,Department of Gynecology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Chaoyun Pan
- Department of Hematology and Medical Oncology, Winship Cancer Institute, Emory University School of Medicine, Atlanta, Georgia
| | - Austin C Boese
- Department of Hematology and Medical Oncology, Winship Cancer Institute, Emory University School of Medicine, Atlanta, Georgia
| | - JiHoon Kang
- Department of Hematology and Medical Oncology, Winship Cancer Institute, Emory University School of Medicine, Atlanta, Georgia
| | - Anna D Umano
- Department of Hematology and Medical Oncology, Winship Cancer Institute, Emory University School of Medicine, Atlanta, Georgia
| | - Kelly R Magliocca
- Department of Pathology & Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Wenqing Yang
- Department of Gynecology, Xiangya Hospital, Central South University, Changsha, Hunan, China.,Gynecological Oncology Research and Engineering Center of Hunan Province, Changsha, Hunan, China
| | - Yu Zhang
- Department of Gynecology, Xiangya Hospital, Central South University, Changsha, Hunan, China.,Gynecological Oncology Research and Engineering Center of Hunan Province, Changsha, Hunan, China
| | - Sagar Lonial
- Department of Hematology and Medical Oncology, Winship Cancer Institute, Emory University School of Medicine, Atlanta, Georgia
| | - Lingtao Jin
- Department of Anatomy and Cell Biology, College of Medicine, University of Florida, Gainesville, Florida
| | - Sumin Kang
- Department of Hematology and Medical Oncology, Winship Cancer Institute, Emory University School of Medicine, Atlanta, Georgia.
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16
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Mechanistic models of PLC/PKC signaling implicate phosphatidic acid as a key amplifier of chemotactic gradient sensing. PLoS Comput Biol 2020; 16:e1007708. [PMID: 32255775 PMCID: PMC7164671 DOI: 10.1371/journal.pcbi.1007708] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 04/17/2020] [Accepted: 02/03/2020] [Indexed: 01/05/2023] Open
Abstract
Chemotaxis of fibroblasts and other mesenchymal cells is critical for embryonic development and wound healing. Fibroblast chemotaxis directed by a gradient of platelet-derived growth factor (PDGF) requires signaling through the phospholipase C (PLC)/protein kinase C (PKC) pathway. Diacylglycerol (DAG), the lipid product of PLC that activates conventional PKCs, is focally enriched at the up-gradient leading edge of fibroblasts responding to a shallow gradient of PDGF, signifying polarization. To explain the underlying mechanisms, we formulated reaction-diffusion models including as many as three putative feedback loops based on known biochemistry. These include the previously analyzed mechanism of substrate-buffering by myristoylated alanine-rich C kinase substrate (MARCKS) and two newly considered feedback loops involving the lipid, phosphatidic acid (PA). DAG kinases and phospholipase D, the enzymes that produce PA, are identified as key regulators in the models. Paradoxically, increasing DAG kinase activity can enhance the robustness of DAG/active PKC polarization with respect to chemoattractant concentration while decreasing their whole-cell levels. Finally, in simulations of wound invasion, efficient collective migration is achieved with thresholds for chemotaxis matching those of polarization in the reaction-diffusion models. This multi-scale modeling framework offers testable predictions to guide further study of signal transduction and cell behavior that affect mesenchymal chemotaxis. Cell movement directed by external gradients of chemical composition is critical for immune responses, wound healing, and development. Although theoretical concepts explaining how shallow external gradients might definitively polarize a cell’s motility have been offered over the past two decades, mathematical models cast in terms of defined molecules and mechanisms are uncommon in this context. Based on both recent and older insights from the literature, we offer mechanistic models that are able to explain experimentally observed polarization of signal transduction elicited by shallow attractant gradients. A novel insight of our models is the implicated role of phosphatidic acid, a membrane lipid produced by at least two enzymatic pathways, in two positive feedback loops that amplify signal transduction locally. In separate simulations, we explored the implications of polarization for efficient cell invasion during wound healing. We expected that the ability to polarize in response to shallow gradients would enhance the speed of wound invasion, but an unexpected finding is that this property can promote intermittent polarization throughout the wound.
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17
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Velnati S, Massarotti A, Antona A, Talmon M, Fresu LG, Galetto AS, Capello D, Bertoni A, Mercalli V, Graziani A, Tron GC, Baldanzi G. Structure activity relationship studies on Amb639752: toward the identification of a common pharmacophoric structure for DGKα inhibitors. J Enzyme Inhib Med Chem 2020; 35:96-108. [PMID: 31690133 PMCID: PMC6844378 DOI: 10.1080/14756366.2019.1684911] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
A series of analogues of Amb639752, a novel diacylglycerol kinase (DGK) inhibitor recently discovered by us via virtual screening, have been tested. The compounds were evaluated as DGK inhibitors on α, θ, and ζ isoforms, and as antagonists on serotonin receptors. From these assays emerged two novel compounds, namely 11 and 20, which with an IC50 respectively of 1.6 and 1.8 µM are the most potent inhibitors of DGKα discovered to date. Both compounds demonstrated the ability to restore apoptosis in a cellular model of X-linked lymphoproliferative disease as well as the capacity to reduce the migration of cancer cells, suggesting their potential utility in preventing metastasis. Finally, relying on experimental biological data, molecular modelling studies allow us to set a three-point pharmacophore model for DGK inhibitors.
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Affiliation(s)
- Suresh Velnati
- Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy.,Institute for Research and Cure of Autoimmune Diseases, CAAD, University of Piemonte Orientale, Novara, Italy
| | - Alberto Massarotti
- Department of Pharmaceutical Sciences, University of Piemonte Orientale, Novara, Italy
| | - Annamaria Antona
- Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy
| | - Maria Talmon
- Department of Health Sciences, School of Medicine, University of Piemonte Orientale, Novara, Italy
| | - Luigia Grazia Fresu
- Department of Health Sciences, School of Medicine, University of Piemonte Orientale, Novara, Italy
| | - Alessandra Silvia Galetto
- Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy.,Palliative Care Division, A.S.L., Vercelli, Italy
| | - Daniela Capello
- Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy
| | - Alessandra Bertoni
- Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy
| | - Valentina Mercalli
- Department of Pharmaceutical Sciences, University of Piemonte Orientale, Novara, Italy
| | - Andrea Graziani
- Università Vita-Salute San Raffaele, Milan, Italy.,Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Turin, Italy
| | - Gian Cesare Tron
- Department of Pharmaceutical Sciences, University of Piemonte Orientale, Novara, Italy
| | - Gianluca Baldanzi
- Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy.,Institute for Research and Cure of Autoimmune Diseases, CAAD, University of Piemonte Orientale, Novara, Italy
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18
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Arranz-Nicolás J, Mérida I. Biological regulation of diacylglycerol kinases in normal and neoplastic tissues: New opportunities for cancer immunotherapy. Adv Biol Regul 2020; 75:100663. [PMID: 31706704 DOI: 10.1016/j.jbior.2019.100663] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 09/20/2019] [Accepted: 09/30/2019] [Indexed: 06/10/2023]
Abstract
In the recent years, the arsenal of anti-cancer therapies has evolved to target T lymphocytes and restore their capacity to destroy tumor cells. However, the clinical success is limited, with a large number of patients that never responds and others that ultimately develop resistances. Overcoming the hypofunctional state imposed by solid tumors to T cells has revealed critical but challenging due to the complex strategies that tumors employ to evade the immune system. The Diacylglycerol kinases (DGK) limit DAG-dependent functions in T lymphocytes and their upregulation in tumor-infiltrating T lymphocytes contribute to limit T cell cytotoxic potential. DGK blockade could reinstate T cell attack on tumors, limiting at the same time tumor cell growth, thanks to the DGK positive input into several oncogenic pathways. In this review we summarize the latest findings regarding the regulation of specific DGK isoforms in healthy and anergic T lymphocytes, as well as their contribution to oncogenic phenotypes. We will also revise the latest advances in the search for pharmacological inhibitors and their potential as anti-cancer agents, either alone or in combination with immunomodulatory agents.
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Affiliation(s)
- Javier Arranz-Nicolás
- Department of Immunology and Oncology, National Center for Biotechnology (CNB-CSIC), Darwin 3, UAM Campus de Cantoblanco, 28049, Madrid, Spain
| | - Isabel Mérida
- Department of Immunology and Oncology, National Center for Biotechnology (CNB-CSIC), Darwin 3, UAM Campus de Cantoblanco, 28049, Madrid, Spain.
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19
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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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20
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Merida I, Arranz-Nicolás J, Torres-Ayuso P, Ávila-Flores A. Diacylglycerol Kinase Malfunction in Human Disease and the Search for Specific Inhibitors. Handb Exp Pharmacol 2019; 259:133-162. [PMID: 31227890 DOI: 10.1007/164_2019_221] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The diacylglycerol kinases (DGKs) are master regulator kinases that control the switch from diacylglycerol (DAG) to phosphatidic acid (PA), two lipids with important structural and signaling properties. Mammalian DGKs distribute into five subfamilies that regulate local availability of DAG and PA pools in a tissue- and subcellular-restricted manner. Pharmacological manipulation of DGK activity holds great promise, given the critical contribution of specific DGK subtypes to the control of membrane structure, signaling complexes, and cell-cell communication. The latest advances in the DGK field have unveiled the differential contribution of selected isoforms to human disease. Defects in the expression/activity of individual DGK isoforms contribute substantially to cognitive impairment, mental disorders, insulin resistance, and vascular pathologies. Abnormal DGK overexpression, on the other hand, confers the acquisition of malignant traits including invasion, chemotherapy resistance, and inhibition of immune attack on tumors. Translation of these findings into therapeutic approaches will require development of methods to pharmacologically modulate DGK functions. In particular, inhibitors that target the DGKα isoform hold particular promise in the fight against cancer, on their own or in combination with immune-targeting therapies.
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Affiliation(s)
- Isabel Merida
- Department of Immunology and Oncology, National Center of Biotechnology (CNB-CSIC), Madrid, Spain.
| | - Javier Arranz-Nicolás
- Department of Immunology and Oncology, National Center of Biotechnology (CNB-CSIC), Madrid, Spain
| | - Pedro Torres-Ayuso
- Laboratory of Cell and Developmental Signaling, National Cancer Institute (NCI-NIH), Frederick, MD, USA
| | - Antonia Ávila-Flores
- Department of Immunology and Oncology, National Center of Biotechnology (CNB-CSIC), Madrid, Spain
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21
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Velnati S, Ruffo E, Massarotti A, Talmon M, Varma KSS, Gesu A, Fresu LG, Snow AL, Bertoni A, Capello D, Tron GC, Graziani A, Baldanzi G. Identification of a novel DGKα inhibitor for XLP-1 therapy by virtual screening. Eur J Med Chem 2018; 164:378-390. [PMID: 30611057 PMCID: PMC6599760 DOI: 10.1016/j.ejmech.2018.12.061] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 12/11/2018] [Accepted: 12/24/2018] [Indexed: 11/24/2022]
Abstract
As part of an effort to identify druggable diacylglycerol kinase alpha (DGKα) inhibitors, we used an insilico approach based on chemical homology with the two commercially available DGKα inhibitors R59022 and R59949. Ritanserin and compound AMB639752 emerged from the screening of 127 compounds, showing an inhibitory activity superior to the two commercial inhibitors, being furthermore specific for the alpha isoform of diacylglycerol kinase. Interestingly, AMB639752 was also devoid of serotoninergic activity. The ability of both ritanserin and AMB639752, by inhibiting DGKα in intact cells, to restore restimulation induced cell death (RICD) in SAP deficient lymphocytes was also tested. Both compounds restored RICD at concentrations lower than the two previously available inhibitors, indicating their potential use for the treatment of X-Iinked lymphoproliferative disease 1 (XLP-1), a rare genetic disorder in which DGKα activity is deregulated.
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Affiliation(s)
- Suresh Velnati
- Department of Translational Medicine and Center for Translational Research on Autoimmune and Allergic Diseases (CAAD), University of Piemonte Orientale, 28100, Novara, Italy
| | - Elisa Ruffo
- School of Medicine, University Vita e Salute San Raffaele, 20132, Milan, Italy
| | - Alberto Massarotti
- Department of Pharmaceutical Science, University of Piemonte Orientale, 28100, Novara, Italy
| | - Maria Talmon
- Department of Health Sciences, School of Medicine, University of Piemonte Orientale, 28100, Novara, Italy
| | - Konduru Sai Sandeep Varma
- Department of Translational Medicine and Center for Translational Research on Autoimmune and Allergic Diseases (CAAD), University of Piemonte Orientale, 28100, Novara, Italy
| | - Alessandro Gesu
- Department of Pharmaceutical Science, University of Piemonte Orientale, 28100, Novara, Italy
| | - Luigia Grazia Fresu
- Department of Health Sciences, School of Medicine, University of Piemonte Orientale, 28100, Novara, Italy
| | - Andrew L Snow
- Department of Pharmacology and Molecular Therapeutics, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | - Alessandra Bertoni
- Department of Translational Medicine and Center for Translational Research on Autoimmune and Allergic Diseases (CAAD), University of Piemonte Orientale, 28100, Novara, Italy
| | - Daniela Capello
- Department of Translational Medicine and Center for Translational Research on Autoimmune and Allergic Diseases (CAAD), University of Piemonte Orientale, 28100, Novara, Italy
| | - Gian Cesare Tron
- Department of Pharmaceutical Science, University of Piemonte Orientale, 28100, Novara, Italy
| | - Andrea Graziani
- School of Medicine, University Vita e Salute San Raffaele, 20132, Milan, Italy.
| | - Gianluca Baldanzi
- Department of Translational Medicine and Center for Translational Research on Autoimmune and Allergic Diseases (CAAD), University of Piemonte Orientale, 28100, Novara, Italy.
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22
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Arranz-Nicolás J, Ogando J, Soutar D, Arcos-Pérez R, Meraviglia-Crivelli D, Mañes S, Mérida I, Ávila-Flores A. Diacylglycerol kinase α inactivation is an integral component of the costimulatory pathway that amplifies TCR signals. Cancer Immunol Immunother 2018; 67:965-980. [PMID: 29572701 PMCID: PMC11028345 DOI: 10.1007/s00262-018-2154-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 03/19/2018] [Indexed: 12/18/2022]
Abstract
The arsenal of cancer therapies has evolved to target T lymphocytes and restore their capacity to destroy tumor cells. T cells rely on diacylglycerol (DAG) to carry out their functions. DAG availability and signaling are regulated by the enzymes diacylglycerol kinase (DGK) α and ζ, whose excess function drives T cells into hyporesponsive states. Targeting DGKα is a promising strategy for coping with cancer; its blockade could reinstate T-cell attack on tumors while limiting tumor growth, due to positive DGKα functions in several oncogenic pathways. Here, we made a side-by-side comparison of the effects of commercial pharmacological DGK inhibitors on T-cell responses with those promoted by DGKα and DGKζ genetic deletion or silencing. We show the specificity for DGKα of DGK inhibitors I and II and the structurally similar compound ritanserin. Inhibitor treatment promoted Ras/ERK (extracellular signal-regulated kinase) signaling and AP-1 (Activator protein-1) transcription, facilitated DGKα membrane localization, reduced the requirement for costimulation, and cooperated with enhanced activation following DGKζ silencing/deletion. DGKiII and ritanserin had similar effects on TCR proximal signaling, but ritanserin counteracted long-term T-cell activation, an effect that was potentiated in DGKα-/- cells. In contrast with enhanced activation triggered by pharmacological inhibition, DGKα silencing/genetic deletion led to impaired Lck (lymphocyte-specific protein tyrosine kinase) activation and limited costimulation responses. Our results demonstrate that pharmacological inhibition of DGKα downstream of the TCR provides a gain-of-function effect that amplifies the DAG-dependent signaling cascade, an ability that could be exploited therapeutically to reinvigorate T cells to attack tumors.
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Affiliation(s)
- Javier Arranz-Nicolás
- Department of Immunology and Oncology, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, UAM Campus de Cantoblanco, 28049, Madrid, Spain
| | - Jesús Ogando
- Department of Immunology and Oncology, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, UAM Campus de Cantoblanco, 28049, Madrid, Spain
| | - Denise Soutar
- Department of Immunology and Oncology, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, UAM Campus de Cantoblanco, 28049, Madrid, Spain
| | - Raquel Arcos-Pérez
- Department of Immunology and Oncology, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, UAM Campus de Cantoblanco, 28049, Madrid, Spain
| | - Daniel Meraviglia-Crivelli
- Department of Immunology and Oncology, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, UAM Campus de Cantoblanco, 28049, Madrid, Spain
| | - Santos Mañes
- Department of Immunology and Oncology, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, UAM Campus de Cantoblanco, 28049, Madrid, Spain
| | - Isabel Mérida
- Department of Immunology and Oncology, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, UAM Campus de Cantoblanco, 28049, Madrid, Spain.
| | - Antonia Ávila-Flores
- Department of Immunology and Oncology, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, UAM Campus de Cantoblanco, 28049, Madrid, Spain.
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23
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You JS, Dooley MS, Kim CR, Kim EJ, Xu W, Goodman CA, Hornberger TA. A DGKζ-FoxO-ubiquitin proteolytic axis controls fiber size during skeletal muscle remodeling. Sci Signal 2018; 11:11/530/eaao6847. [PMID: 29764991 DOI: 10.1126/scisignal.aao6847] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Skeletal muscle rapidly remodels in response to various stresses, and the resulting changes in muscle mass profoundly influence our health and quality of life. We identified a diacylglycerol kinase ζ (DGKζ)-mediated pathway that regulated muscle mass during remodeling. During mechanical overload, DGKζ abundance was increased and required for effective hypertrophy. DGKζ not only augmented anabolic responses but also suppressed ubiquitin-proteasome system (UPS)-dependent proteolysis. We found that DGKζ inhibited the transcription factor FoxO that promotes the induction of the UPS. This function was mediated through a mechanism that was independent of kinase activity but dependent on the nuclear localization of DGKζ. During denervation, DGKζ abundance was also increased and was required for mitigating the activation of FoxO-UPS and the induction of atrophy. Conversely, overexpression of DGKζ prevented fasting-induced atrophy. Therefore, DGKζ is an inhibitor of the FoxO-UPS pathway, and interventions that increase its abundance could prevent muscle wasting.
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Affiliation(s)
- Jae-Sung You
- Program in Cellular and Molecular Biology, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI 53706, USA. .,Department of Comparative Biosciences in the School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI 53706, USA.,Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, 601 South Goodwin Avenue, Urbana, IL 61801, USA
| | - Matthew S Dooley
- Department of Comparative Biosciences in the School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI 53706, USA
| | - Chan-Ran Kim
- Department of Comparative Biosciences in the School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI 53706, USA
| | - Eui-Jun Kim
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705, USA
| | - Wei Xu
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705, USA
| | - Craig A Goodman
- Department of Comparative Biosciences in the School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI 53706, USA.,College of Health and Biomedicine, Victoria University, Melbourne, Victoria 8001, Australia.,Institute for Sport, Exercise and Active Living, Victoria University, Melbourne, Victoria 8001, Australia.,Australian Institute of Musculoskeletal Science, Victoria University, St. Albans, Victoria 3021, Australia
| | - Troy A Hornberger
- Program in Cellular and Molecular Biology, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI 53706, USA. .,Department of Comparative Biosciences in the School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI 53706, USA
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24
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Shimomura T, Nakano T, Goto K, Wakabayashi I. R59949, a diacylglycerol kinase inhibitor, inhibits inducible nitric oxide production through decreasing transplasmalemmal L-arginine uptake in vascular smooth muscle cells. Naunyn Schmiedebergs Arch Pharmacol 2016; 390:207-214. [PMID: 27909743 DOI: 10.1007/s00210-016-1316-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 11/14/2016] [Indexed: 01/26/2023]
Abstract
Although diacylglycerol kinase (DGK) is known to be expressed in vascular smooth muscle cell, its functional significance remains to be clarified. We hypothesized that DGK is involved in the pathway of cytokine-induced nitric oxide (NO) production in vascular smooth muscle cells. The purpose of this study was to investigate the effects of R59949, a diacylglycerol kinase inhibitor, on inducible nitric oxide production in vascular smooth muscle cell. Cultured rat aortic smooth muscle cells (RASMCs) were used to elucidate the effects of R59949 on basal and interleukin-1β (IL-1β)-induced NO production. The effects of R59949 on protein and mRNA expression of induced nitric oxide synthase (iNOS) and on transplasmalemmal L-arginine uptake were also evaluated using RASMCs. Treatment of RASMCs with R59949 (10 μM) inhibited IL-1β (10 ng/ml)-induced NO production but not basal NO production. Neither protein nor mRNA expression level of iNOS after stimulation with IL-1β was significantly affected by R59949. Estimated enzymatic activities of iNOS in RASMCs were comparable in the absence and presence of R59949. Stimulation of RASMCs with IL-1β caused a marked increase in transplasmalemmal L-arginine uptake into RASMCs. L-Arginine uptake in the presence of IL-1β was markedly inhibited by R59949, while basal L-arginine uptake was not significantly affected by R59949. Both IL-1β-induced NO production and L-arginine uptake were abolished in the presence of cycloheximide (1 μM). The results indicate that R59949 inhibits inducible NO production through decreasing transplasmalemmal L-arginine uptake. DGK is suggested to be involved in cytokine-stimulated L-arginine transport and regulate its intracellular concentration in vascular smooth muscle cell.
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Affiliation(s)
- Tomoko Shimomura
- Department of Environmental and Preventive Medicine, Hyogo College of Medicine, Mukogawa-cho 1-1, Nishinomiya, Hyogo, 663-8501, Japan
| | - Tomoyuki Nakano
- Department of Anatomy and Cell Biology, Yamagata University Faculty of Medicine, Iida-nishi 2-2-2, Yamagata, 990-9585, Japan
| | - Kaoru Goto
- Department of Anatomy and Cell Biology, Yamagata University Faculty of Medicine, Iida-nishi 2-2-2, Yamagata, 990-9585, Japan
| | - Ichiro Wakabayashi
- Department of Environmental and Preventive Medicine, Hyogo College of Medicine, Mukogawa-cho 1-1, Nishinomiya, Hyogo, 663-8501, Japan.
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25
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Boroda S, Niccum M, Raje V, Purow BW, Harris TE. Dual activities of ritanserin and R59022 as DGKα inhibitors and serotonin receptor antagonists. Biochem Pharmacol 2016; 123:29-39. [PMID: 27974147 DOI: 10.1016/j.bcp.2016.10.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 10/25/2016] [Indexed: 11/17/2022]
Abstract
Diacylglycerol kinase alpha (DGKα) catalyzes the conversion of diacylglycerol (DAG) to phosphatidic acid (PA). Recently, DGKα was identified as a therapeutic target in various cancers, as well as in immunotherapy. Application of small-molecule DGK inhibitors, R59022 and R59949, induces cancer cell death in vitro and in vivo. The pharmacokinetics of these compounds in mice, however, are poor. Thus, there is a need to discover additional DGK inhibitors not only to validate these enzymes as targets in oncology, but also to achieve a better understanding of their biology. In the present study, we investigate the activity of ritanserin, a compound structurally similar to R59022, against DGKα. Ritanserin, originally characterized as a serotonin (5-HT) receptor (5-HTR) antagonist, underwent clinical trials as a potential medicine for the treatment of schizophrenia and substance dependence. We document herein that ritanserin attenuates DGKα kinase activity while increasing the enzyme's affinity for ATP in vitro. In addition, R59022 and ritanserin function as DGKα inhibitors in cultured cells and activate protein kinase C (PKC). While recognizing that ritanserin attenuates DGK activity, we also find that R59022 and R59949 are 5-HTR antagonists. In conclusion, ritanserin, R59022 and R59949 are combined pharmacological inhibitors of DGKα and 5-HTRs in vitro.
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Affiliation(s)
- Salome Boroda
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22903, USA
| | - Maria Niccum
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22903, USA
| | - Vidisha Raje
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22903, USA
| | - Benjamin W Purow
- Department of Neurology, University of Virginia School of Medicine, Charlottesville, VA 22903, USA.
| | - Thurl E Harris
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22903, USA.
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26
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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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27
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Kamerbeek CB, Mateos MV, Vallés AS, Pediconi MF, Barrantes FJ, Borroni V. Diacylglycerol levels modulate the cellular distribution of the nicotinic acetylcholine receptor. Int J Biochem Cell Biol 2016; 74:1-11. [PMID: 26898898 DOI: 10.1016/j.biocel.2016.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Revised: 02/03/2016] [Accepted: 02/15/2016] [Indexed: 10/22/2022]
Abstract
Diacylglycerol (DAG), a second messenger involved in different cell signaling cascades, activates protein kinase C (PKC) and D (PKD), among other kinases. The present work analyzes the effects resulting from the alteration of DAG levels on neuronal and muscle nicotinic acetylcholine receptor (AChR) distribution. We employ CHO-K1/A5 cells, expressing adult muscle-type AChR in a stable manner, and hippocampal neurons, which endogenously express various subtypes of neuronal AChR. CHO-K1/A5 cells treated with dioctanoylglycerol (DOG) for different periods showed augmented AChR cell surface levels at short incubation times (30min-4h) whereas at longer times (18h) the AChR was shifted to intracellular compartments. Similarly, in cultured hippocampal neurons surface AChR levels increased as a result of DOG incubation for 4h. Inhibition of endogenous DAG catabolism produced changes in AChR distribution similar to those induced by DOG treatment. Specific enzyme inhibitors and Western blot assays revealed that DAGs exert their effect on AChR distribution through the modulation of the activity of classical PKC (cPKC), novel PKC (nPKC) and PKD activity.
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Affiliation(s)
- Constanza B Kamerbeek
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Camino La Carrindanga km 7, 8000 Bahía Blanca, Argentina
| | - Melina V Mateos
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Camino La Carrindanga km 7, 8000 Bahía Blanca, Argentina
| | - Ana S Vallés
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Camino La Carrindanga km 7, 8000 Bahía Blanca, Argentina
| | - María F Pediconi
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Camino La Carrindanga km 7, 8000 Bahía Blanca, Argentina
| | - Francisco J Barrantes
- Laboratory of Molecular Neurobiology, Institute for Biomedical Research UCA-CONICET, Faculty of Medical Sciences, Av. Alicia Moreau de Justo 1600, C1107AFF Buenos Aires, Argentina
| | - Virginia Borroni
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Camino La Carrindanga km 7, 8000 Bahía Blanca, Argentina.
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28
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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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29
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RasGRP1 overexpression in T-ALL increases basal nucleotide exchange on Ras rendering the Ras/PI3K/Akt pathway responsive to protumorigenic cytokines. Oncogene 2015; 35:3658-68. [PMID: 26549032 DOI: 10.1038/onc.2015.431] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 08/31/2015] [Accepted: 10/05/2015] [Indexed: 12/25/2022]
Abstract
Ras GTPases are activated by RasGEFs and inactivated by RasGAPs, which stimulate the hydrolysis of RasGTP to inactive RasGDP. GTPase-impairing somatic mutations in RAS genes, such as KRAS(G12D), are among the most common oncogenic events in metastatic cancer. A different type of cancer Ras signal, driven by overexpression of the RasGEF RasGRP1 (Ras guanine nucleotide-releasing protein 1), was recently implicated in pediatric T-cell acute lymphoblastic leukemia (T-ALL) patients and murine models, in which RasGRP1 T-ALLs expand in response to treatment with interleukins (ILs) 2, 7 and 9. Here, we demonstrate that IL-2/7/9 stimulation activates Erk and Akt pathways downstream of Ras in RasGRP1 T-ALL but not in normal thymocytes. In normal lymphocytes, RasGRP1 is recruited to the membrane by diacylglycerol (DAG) in a phospholipase C-γ (PLCγ)-dependent manner. Surprisingly, we find that leukemic RasGRP1-triggered Ras-Akt signals do not depend on acute activation of PLCγ to generate DAG but rely on baseline DAG levels instead. In agreement, using three distinct assays that measure different aspects of the RasGTP/GDP cycle, we established that overexpression of RasGRP1 in T-ALLs results in a constitutively high GTP-loading rate of Ras, which is constantly counterbalanced by hydrolysis of RasGTP. KRAS(G12D) T-ALLs do not show constitutive GTP loading of Ras. Thus, we reveal an entirely novel type of leukemogenic Ras signals that is based on a RasGRP1-driven increased in flux through the RasGTP/GDP cycle, which is mechanistically very different from KRAS(G12D) signals. Our studies highlight the dynamic balance between RasGEF and RasGAP in these T-ALLs and put forth a new model in which IL-2/7/9 decrease RasGAP activity.
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30
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Torres-Ayuso P, Tello-Lafoz M, Mérida I, Ávila-Flores A. Diacylglycerol kinase-ζ regulates mTORC1 and lipogenic metabolism in cancer cells through SREBP-1. Oncogenesis 2015; 4:e164. [PMID: 26302180 PMCID: PMC4632073 DOI: 10.1038/oncsis.2015.22] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 06/26/2015] [Accepted: 07/07/2015] [Indexed: 01/03/2023] Open
Abstract
Diacylglycerol kinases (DGKs) transform diacylglycerol (DAG) into phosphatidic acid (PA), balancing the levels of these key metabolic and signaling lipids. We previously showed that PA derived from the DGKζ isoform promotes mammalian target of rapamycin complex 1 (mTORC1) activation. This function might be crucial for the growth and survival of cancer cells, especially for those resistant to the allosteric mTOR inhibitor rapamycin. How this positive function of DGKζ coordinates with DAG metabolism and signaling is unknown. In this study, we used a rapamycin-resistant colon cancer cell line as a model to address the role of DGKζ in tumor cells. We found that DGKζ predominated over other PA sources such as DGKα or phospholipase D to activate mTORC1, and that its activity was a component of the rapamycin-induced feedback loops. We show that the DGKζ DAG-consuming function is central to cell homeostasis, as DAG negatively regulates levels of the lipogenic transcription factor SREBP-1. Our findings suggest a model in which simultaneous regulation of DAG and PA levels by DGKζ is integrated with mTOR function to maintain tumor cell homeostasis; we provide new evidence of the crosstalk between mTOR and lipid metabolism that will be advantageous in the design of drug therapies.
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Affiliation(s)
- P Torres-Ayuso
- Department of Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Madrid, Spain
| | - M Tello-Lafoz
- Department of Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Madrid, Spain
| | - I Mérida
- Department of Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Madrid, Spain
| | - A Ávila-Flores
- Department of Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Madrid, Spain
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31
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Xie S, Naslavsky N, Caplan S. Diacylglycerol kinases in membrane trafficking. CELLULAR LOGISTICS 2015; 5:e1078431. [PMID: 27057419 DOI: 10.1080/21592799.2015.1078431] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 07/22/2015] [Accepted: 07/24/2015] [Indexed: 10/23/2022]
Abstract
Diacylglycerol kinases (DGKs) belong to a family of cytosolic kinases that regulate the phosphorylation of diacylglycerol (DAG), converting it into phosphatidic acid (PA). There are 10 known mammalian DGK isoforms, each with a different tissue distribution and substrate specificity. These differences allow regulation of cellular responses by fine-tuning the delicate balance of cellular DAG and PA. DGK isoforms are best characterized as mediators of signal transduction and immune function. However, since recent studies reveal that DAG and PA are also involved in the regulation of endocytic trafficking, it is therefore anticipated that DGKs also plays an important role in membrane trafficking. In this review, we summarize the literature discussing the role of DGK isoforms at different stages of endocytic trafficking, including endocytosis, exocytosis, endocytic recycling, and transport from/to the Golgi apparatus. Overall, these studies contribute to our understanding of the involvement of PA and DAG in endocytic trafficking, an area of research that is drawing increasing attention in recent years.
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Affiliation(s)
- Shuwei Xie
- Department of Biochemistry and Molecular Biology and the Fred and Pamela Buffett Cancer Center; University of Nebraska Medical Center ; Omaha, NE USA
| | - Naava Naslavsky
- Department of Biochemistry and Molecular Biology and the Fred and Pamela Buffett Cancer Center; University of Nebraska Medical Center ; Omaha, NE USA
| | - Steve Caplan
- Department of Biochemistry and Molecular Biology and the Fred and Pamela Buffett Cancer Center; University of Nebraska Medical Center ; Omaha, NE USA
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32
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Torres-Ayuso P, Daza-Martín M, Martín-Pérez J, Ávila-Flores A, Mérida I. Diacylglycerol kinase α promotes 3D cancer cell growth and limits drug sensitivity through functional interaction with Src. Oncotarget 2015; 5:9710-26. [PMID: 25339152 PMCID: PMC4259432 DOI: 10.18632/oncotarget.2344] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 08/11/2014] [Indexed: 02/02/2023] Open
Abstract
Diacylglycerol kinase (DGK)α converts diacylglycerol to phosphatidic acid. This lipid kinase sustains survival, migration and invasion of tumor cells, with no effect over untransformed cells, suggesting its potential as a cancer-specific target. Nonetheless the mechanisms that underlie DGKα specific contribution to cancer survival have not been elucidated. Using three-dimensional (3D) colon and breast cancer cell cultures, we demonstrate that DGKα upregulation is part of the transcriptional program that results in Src activation in these culture conditions. Pharmacological or genetic DGKα silencing impaired tumor growth in vivo confirming its function in malignant transformation. DGKα-mediated Src regulation contributed to limit the effect of Src inhibitors, and its transcriptional upregulation in response to PI3K/Akt inhibitors resulted in reduced toxicity. Src oncogenic properties and contribution to pharmacological resistance have been linked to its overactivation in cancer. DGKα participation in this central node helps to explain why its pharmacological inhibition or siRNA-mediated targeting specifically alters tumor viability with no effect on untransformed cells. Our results identify DGKα-mediated stabilization of Src activation as an important mechanism in tumor growth, and suggest that targeting this enzyme, alone or in combination with other inhibitors in wide clinical use, could constitute a treatment strategy for aggressive forms of cancer.
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Affiliation(s)
- Pedro Torres-Ayuso
- Department of Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Madrid, Spain
| | - Manuel Daza-Martín
- Department of Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Madrid, Spain
| | - Jorge Martín-Pérez
- Department of Cancer Biology, Instituto de Investigaciones Biomédicas Alberto Sols/CSIC, Universidad Autónoma de Madrid, Madrid, Spain
| | - Antonia Ávila-Flores
- Department of Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Madrid, Spain
| | - Isabel Mérida
- Department of Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Madrid, Spain
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García del Caño G, Aretxabala X, González-Burguera I, Montaña M, López de Jesús M, Barrondo S, Barrio RJ, Sampedro C, Goicolea MA, Sallés J. Nuclear diacylglycerol lipase-α in rat brain cortical neurons: evidence of 2-arachidonoylglycerol production in concert with phospholipase C-β activity. J Neurochem 2014; 132:489-503. [PMID: 25308538 DOI: 10.1111/jnc.12963] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 09/22/2014] [Accepted: 10/07/2014] [Indexed: 01/12/2023]
Abstract
In this report, we describe the localization of diacylglycerol lipase-α (DAGLα) in nuclei from adult cortical neurons, as assessed by double-immunofluorescence staining of rat brain cortical sections and purified intact nuclei and by western blot analysis of subnuclear fractions. Double-labeling assays using the anti-DAGLα antibody and NeuN combined with Hoechst staining showed that only nuclei of neuronal origin were DAGLα positive. At high resolution, DAGLα-signal displayed a punctate pattern in nuclear subdomains poor in Hoechst's chromatin and lamin B1 staining. In contrast, SC-35- and NeuN-signals (markers of the nuclear speckles) showed a high overlap with DAGLα within specific subdomains of the nuclear matrix. Among the members of the phospholipase C-β (PLCβ) family, PLCβ1, PLCβ2, and PLCβ4 exhibited the same distribution with respect to chromatin, lamin B1, SC-35, and NeuN as that described for DAGLα. Furthermore, by quantifying the basal levels of 2-arachidonoylglycerol (2-AG) by liquid chromatography and mass spectrometry (LC-MS), and by characterizing the pharmacology of its accumulation, we describe the presence of a mechanism for 2-AG production, and its PLCβ/DAGLα-dependent biosynthesis in isolated nuclei. These results extend our knowledge about subcellular distribution of neuronal DAGLα, providing biochemical grounds to hypothesize a role for 2-AG locally produced within the neuronal nucleus.
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Affiliation(s)
- Gontzal García del Caño
- Departamento de Neurociencias, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), 01006 Vitoria-Gasteiz (Araba), Spain
| | - Xabier Aretxabala
- Departamento de Neurociencias, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), 01006 Vitoria-Gasteiz (Araba), Spain
| | - Imanol González-Burguera
- Departamento de Farmacología, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), 01006 Vitoria-Gasteiz (Araba), Spain
| | - Mario Montaña
- Departamento de Farmacología, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), 01006 Vitoria-Gasteiz (Araba), Spain
| | - Maider López de Jesús
- Departamento de Farmacología, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), 01006 Vitoria-Gasteiz (Araba), Spain
| | - Sergio Barrondo
- Departamento de Farmacología, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), 01006 Vitoria-Gasteiz (Araba), Spain
| | - Ramón J Barrio
- Departamento de Química Analítica, Facultad de Farmacia, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), 01006 Vitoria-Gasteiz (Araba), Spain
| | - Carmen Sampedro
- Servicio General de Análisis, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), 01006 Vitoria-Gasteiz (Araba), Spain
| | - M Arantzazu Goicolea
- Departamento de Química Analítica, Facultad de Farmacia, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), 01006 Vitoria-Gasteiz (Araba), Spain
| | - Joan Sallés
- Departamento de Farmacología, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), 01006 Vitoria-Gasteiz (Araba), Spain
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Scott SA, Mathews TP, Ivanova PT, Lindsley CW, Brown HA. Chemical modulation of glycerolipid signaling and metabolic pathways. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1841:1060-84. [PMID: 24440821 DOI: 10.1016/j.bbalip.2014.01.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 01/06/2014] [Accepted: 01/07/2014] [Indexed: 01/04/2023]
Abstract
Thirty years ago, glycerolipids captured the attention of biochemical researchers as novel cellular signaling entities. We now recognize that these biomolecules occupy signaling nodes critical to a number of physiological and pathological processes. Thus, glycerolipid-metabolizing enzymes present attractive targets for new therapies. A number of fields-ranging from neuroscience and cancer to diabetes and obesity-have elucidated the signaling properties of glycerolipids. The biochemical literature teems with newly emerging small molecule inhibitors capable of manipulating glycerolipid metabolism and signaling. This ever-expanding pool of chemical modulators appears daunting to those interested in exploiting glycerolipid-signaling pathways in their model system of choice. This review distills the current body of literature surrounding glycerolipid metabolism into a more approachable format, facilitating the application of small molecule inhibitors to novel systems. This article is part of a Special Issue entitled Tools to study lipid functions.
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Affiliation(s)
- Sarah A Scott
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Thomas P Mathews
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Pavlina T Ivanova
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Craig W Lindsley
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA; Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37235, USA
| | - H Alex Brown
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Biochemistry, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37235, USA.
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You JS, Lincoln HC, Kim CR, Frey JW, Goodman CA, Zhong XP, Hornberger TA. The role of diacylglycerol kinase ζ and phosphatidic acid in the mechanical activation of mammalian target of rapamycin (mTOR) signaling and skeletal muscle hypertrophy. J Biol Chem 2013; 289:1551-63. [PMID: 24302719 DOI: 10.1074/jbc.m113.531392] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The activation of mTOR signaling is essential for mechanically induced changes in skeletal muscle mass, and previous studies have suggested that mechanical stimuli activate mTOR (mammalian target of rapamycin) signaling through a phospholipase D (PLD)-dependent increase in the concentration of phosphatidic acid (PA). Consistent with this conclusion, we obtained evidence which further suggests that mechanical stimuli utilize PA as a direct upstream activator of mTOR signaling. Unexpectedly though, we found that the activation of PLD is not necessary for the mechanically induced increases in PA or mTOR signaling. Motivated by this observation, we performed experiments that were aimed at identifying the enzyme(s) that promotes the increase in PA. These experiments revealed that mechanical stimulation increases the concentration of diacylglycerol (DAG) and the activity of DAG kinases (DGKs) in membranous structures. Furthermore, using knock-out mice, we determined that the ζ isoform of DGK (DGKζ) is necessary for the mechanically induced increase in PA. We also determined that DGKζ significantly contributes to the mechanical activation of mTOR signaling, and this is likely driven by an enhanced binding of PA to mTOR. Last, we found that the overexpression of DGKζ is sufficient to induce muscle fiber hypertrophy through an mTOR-dependent mechanism, and this event requires DGKζ kinase activity (i.e. the synthesis of PA). Combined, these results indicate that DGKζ, but not PLD, plays an important role in mechanically induced increases in PA and mTOR signaling. Furthermore, this study suggests that DGKζ could be a fundamental component of the mechanism(s) through which mechanical stimuli regulate skeletal muscle mass.
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Affiliation(s)
- Jae-Sung You
- From the Program in Cellular and Molecular Biology and
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Kurohane Kaneko Y, Kobayashi Y, Motoki K, Nakata K, Miyagawa S, Yamamoto M, Hayashi D, Shirai Y, Sakane F, Ishikawa T. Depression of type I diacylglycerol kinases in pancreatic β-cells from male mice results in impaired insulin secretion. Endocrinology 2013; 154:4089-98. [PMID: 24035999 DOI: 10.1210/en.2013-1356] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Diacylglycerol kinase (DGK) catalyzes the conversion of diacylglycerol (DAG) to phosphatidic acid. This study investigated the expression and function of DGK in pancreatic β-cells. mRNA expression of type I DGK isoforms (α, β, γ) was detected in mouse pancreatic islets and the β-cell line MIN6. Protein expression of DGKα and DGKγ was also detected in mouse β-cells and MIN6 cells. The type I DGK inhibitor R59949 inhibited high K(+)- and glucose-induced insulin secretion in MIN6 cells. Moreover, single knockdown of DGKα or DGKγ by small interfering RNA slightly but significantly decreased glucose- and high K(+)-induced insulin secretions, and the double knockdown further decreased them to the levels comparable with those induced by R59949. R59949 and DiC8, a membrane permeable DAG analog, decreased intracellular Ca(2+) concentration elevated by glucose and high K(+) in MIN6 cells. Real-time imaging in MIN6 cells expressing green fluorescent protein-tagged DGKα or DGKγ showed that the DGK activator phorbol 12-myristate 13-acetate rapidly induced translocation of DGKγ to the plasma membrane, whereas high K(+) slowly translocated DGKα and DGKγ to the plasma membrane. R59949 increased the DAG content in MIN6 cells when stimulated with high KCl, whereas it did not increase the DAG content but decreased the phosphatidic acid content when stimulated with high glucose. Finally, R59949 was confirmed to inhibit high K(+)-induced insulin secretion from mouse islets and glucose-induced insulin secretion from rat islets. These results suggest that DGKα and DGKγ are present in β-cells and that the depression of these DGKs causes a decrease in intracellular Ca(2+) concentration, thereby reducing insulin secretion.
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Wheeler ML, Dong MB, Brink R, Zhong XP, DeFranco AL. Diacylglycerol kinase ζ limits B cell antigen receptor-dependent activation of ERK signaling to inhibit early antibody responses. Sci Signal 2013; 6:ra91. [PMID: 24129701 DOI: 10.1126/scisignal.2004189] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Signaling downstream of the B cell antigen receptor (BCR) is tightly regulated to enable cells to gauge the strength and duration of antigen-receptor interactions and to respond appropriately. We investigated whether metabolism of the second messenger diacylglycerol (DAG) by members of the family of DAG kinases (DGKs) played a role in modulating the magnitude of signaling by DAG downstream of the BCR. In the absence of DGKζ, the threshold for BCR signaling, measured as activation of the Ras-extracellular signal-regulated kinase (ERK) pathway, was markedly reduced in mature follicular B cells, which resulted in enhanced responses to antigen in vitro and in vivo. Inhibition of DAG signaling by DGKζ limited the number of antibody-secreting cells that were generated early in response to T cell-independent type 2 antigens, as well as to T cell-dependent antigens. Furthermore, the effect of loss of DGKζ closely resembled the effect of increasing the affinity of the BCR for antigen during the T cell-dependent antibody response. These results suggest that the magnitude of DAG signaling is important for translating the affinity of the BCR for antigen into the amount of antibody produced during the early stages of an immune response.
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Affiliation(s)
- Matthew L Wheeler
- 1Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA
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Chang MY, Wu TC, Lin ST. BF3-OEt2-Mediated Rearrangement of (4-Phenylpiperidin-4-Yl)-Arylmethanols. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.200800070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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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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Scott SA, Xiang Y, Mathews TP, Cho HP, Myers DS, Armstrong MD, Tallman KA, O'Reilly MC, Lindsley CW, Brown HA. Regulation of phospholipase D activity and phosphatidic acid production after purinergic (P2Y6) receptor stimulation. J Biol Chem 2013; 288:20477-87. [PMID: 23723068 DOI: 10.1074/jbc.m113.451708] [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] [Indexed: 12/22/2022] Open
Abstract
Phosphatidic acid (PA) is a lipid second messenger located at the intersection of several lipid metabolism and cell signaling events including membrane trafficking, survival, and proliferation. Generation of signaling PA has long been primarily attributed to the activation of phospholipase D (PLD). PLD catalyzes the hydrolysis of phosphatidylcholine into PA. A variety of both receptor-tyrosine kinase and G-protein-coupled receptor stimulations have been shown to lead to PLD activation and PA generation. This study focuses on profiling the PA pool upon P2Y6 receptor signaling manipulation to determine the major PA producing enzymes. Here we show that PLD, although highly active, is not responsible for the majority of stable PA being produced upon UDP stimulation of the P2Y6 receptor and that PA levels are tightly regulated. By following PA flux in the cell we show that PLD is involved in an initial increase in PA upon receptor stimulation; however, when PLD is blocked, the cell compensates by increasing PA production from other sources. We further delineate the P2Y6 signaling pathway showing that phospholipase Cβ3 (PLCβ3), PLCδ1, DGKζ and PLD are all downstream of receptor activation. We also show that DGKζ is a novel negative regulator of PLD activity in this system that occurs through an inhibitory mechanism with PKCα. These results further define the downstream events resulting in PA production in the P2Y6 receptor signaling pathway.
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Affiliation(s)
- Sarah A Scott
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA
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Diacylglycerol kinase epsilon in bovine and rat photoreceptor cells. Light-dependent distribution in photoreceptor cells. Exp Eye Res 2013; 112:139-50. [PMID: 23608524 DOI: 10.1016/j.exer.2013.04.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 04/12/2013] [Accepted: 04/13/2013] [Indexed: 11/22/2022]
Abstract
The present study shows the selective light-dependent distribution of 1,2-diacylglycerol kinase epsilon (DAGKɛ) in photoreceptor cells from bovine and albino rat retina. Immunofluorescence microscopy in isolated rod outer segments from bleached bovine retinas (BBROS) revealed a higher DAGKɛ signal than that found in rod outer segments from dark-adapted bovine retinas (BDROS). The light-dependent outer segment localization of DAGKɛ was also observed by immunohistochemistry in retinas from albino rats. DAGK activity, measured in terms of phosphatidic acid formation from a) [(3)H]DAG and ATP in the presence of EGTA and R59022, a type I DAGK inhibitor, or b) [γ-(32)P]ATP and 1-stearoyl, 2-arachidonoylglycerol (SAG), was found to be significantly higher in BBROS than in BDROS. Higher light-dependent DAGK activity (condition b) was also found when ROS were isolated from dark-adapted rat retinas exposed to light. Western blot analysis of isolated ROS proteins from bovine and rat retinas confirmed that illumination increases DAGKɛ content in the outer segments of these two species. Light-dependent DAGKɛ localization in the outer segment was not observed when U73122, a phospholipase C inhibitor, was present prior to the exposure of rat eyecups (in situ model) to light. Furthermore, no increased PA synthesis from [(3)H]DAG and ATP was observed in the presence of neomycin prior to the exposure of bovine eyecups to light. Interestingly, when BBROS were pre-phosphorylated with ATP in the presence of 1,2-dioctanoyl sn-glycerol (di-C8) or phorbol dibutyrate (PDBu) as PKC activation conditions, higher DAGK activity was observed than in dephosphorylated controls. Taken together, our findings suggest that the selective distribution of DAGKɛ in photoreceptor cells is a light-dependent mechanism that promotes increased SAG removal and synthesis of 1-stearoyl, 2-arachidonoyl phosphatidic acid in the sensorial portion of this cell, thus demonstrating a novel mechanism of light-regulated DAGK activity in the photoreceptors of two vertebrate species.
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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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Martinez K, Shyamasundar S, Kennedy A, Chuang CC, Marsh A, Kincaid J, Reid T, McIntosh M. Diacylglycerol kinase inhibitor R59022 attenuates conjugated linoleic acid-mediated inflammation in human adipocytes. J Lipid Res 2013; 54:662-670. [PMID: 23264678 PMCID: PMC3617941 DOI: 10.1194/jlr.m031211] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 12/17/2012] [Indexed: 11/20/2022] Open
Abstract
Diacylglycerol kinases (DGK) convert diacylglycerol to phosphatidic acid, which has been reported to stimulate calcium release from the endoplasmic reticulum. Based on our published data showing that trans-10, cis-12 conjugated linoleic acid (t10,c12 CLA)-mediated intracellular calcium accumulation is linked to inflammation and insulin resistance, we hypothesized that inhibiting DGKs with R59022 would prevent t10,c12 CLA-mediated inflammatory signaling and insulin resistance in human adipocytes. Consistent with our hypothesis, R59022 attenuated t10,c12 CLA-mediated i) increased gene expression and protein secretion of interleukin (IL)-8, IL-6, and monocyte chemoattractant protein-1 (MCP-1); ii) increased activation of extracellular signal-related kinase (ERK), cJun-NH2-terminal kinase (JNK), and cJun; iii) increased intracellular calcium levels; iv) suppressed mRNA or protein levels of peroxisome proliferator activated receptor γ, adiponectin, and insulin-dependent glucose transporter 4; and v) decreased fatty acid and glucose uptake and triglyceride content. DGKη was targeted for investigation based on our findings that i) DGKη was highly expressed in primary human adipocytes and time-dependently induced by t10,c12 CLA and that ii) t10,c12 CLA-induced DGKη expression was dose-dependently decreased with R59022. Small interfering RNA (siRNA) targeting DGKη decreased t10,c12 CLA-induced DGKη, IL-8, and MCP-1 gene expression, as well as activation of JNK and cJun. Taken together, these data suggest that DGKs mediate, in part, t10,c12 CLA-induced inflammatory signaling in primary human adipocytes.
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Affiliation(s)
- Kristina Martinez
- Department of Nutrition, University of North Carolina at Greensboro, Greensboro, NC
| | - Shruthi Shyamasundar
- Department of Nutrition, University of North Carolina at Greensboro, Greensboro, NC
| | - Arion Kennedy
- Department of Molecular Physiology, Vanderbilt University Medical Center, Nashville, TN
| | - Chia Chi Chuang
- Department of Nutrition, University of North Carolina at Greensboro, Greensboro, NC
| | - Angel Marsh
- Department of Nutrition, University of North Carolina at Greensboro, Greensboro, NC
| | - Jennifer Kincaid
- Department of Nutrition, University of North Carolina at Greensboro, Greensboro, NC
| | - Tanya Reid
- Department of Nutrition, University of North Carolina at Greensboro, Greensboro, NC
| | - Michael McIntosh
- Department of Nutrition, University of North Carolina at Greensboro, Greensboro, NC
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Petro EJ, Raben DM. Bacterial expression strategies for several Sus scrofa diacylglycerol kinase alpha constructs: solubility challenges. Sci Rep 2013; 3:1609. [PMID: 23558375 PMCID: PMC3617429 DOI: 10.1038/srep01609] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Accepted: 03/19/2013] [Indexed: 01/27/2023] Open
Abstract
We pursued several strategies for expressing either full-length Sus scrofa diacylglycerol kinase (DGK) alpha or the catalytic domain (alphacat) in Escherichia coli. Alphacat could be extracted, refolded, and purified from inclusion bodies, but when subjected to analytical gel filtration chromatography, it elutes in the void volume, in what we conclude are microscopic aggregates unsuitable for x-ray crystallography. Adding glutathione S-transferase, thioredoxin, or maltose binding protein as N-terminal fusion tags did not improve alphacat's solubility. Coexpressing with bacterial chaperones increased the yield of alphacat in the supernatant after high-speed centrifugation, but the protein still elutes in the void upon analytical gel filtration chromatography. We believe our work will be of interest to those interested in the structure of eukaryotic DGKs, so that they know which expression strategies have already been tried, as well as to those interested in protein folding and those interested in chaperone/target-protein interactions.
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Affiliation(s)
- Elizabeth J. Petro
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD
| | - Daniel M. Raben
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD
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Mizuno S, Sakai H, Saito M, Kado S, Sakane F. Diacylglycerol kinase-dependent formation of phosphatidic acid molecular species during interleukin-2 activation in CTLL-2 T-lymphocytes. FEBS Open Bio 2012; 2:267-72. [PMID: 23650609 PMCID: PMC3642166 DOI: 10.1016/j.fob.2012.08.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 08/16/2012] [Accepted: 08/20/2012] [Indexed: 02/02/2023] Open
Abstract
Although effective liquid chromatography (LC)/mass spectrometry (MS) methods enabling the separation of phospholipid molecular species have been developed, there are still problems with an intracellular signaling molecule, phosphatidic acid (PA). In this study, we optimized LC/MS conditions to improve the quantitative detection of PA molecular species from a cellular lipid mixture. Using the newly developed LC/MS method, we showed that stimulation of CTLL-2 murine T-lymphocytes by interleukin-2 (IL-2) induced a significant increase of 36:1-, 36:2-, 40:5- and 40:6-diacyl-PA. A diacylglycerol kinase (DGK) inhibitor, R59949, attenuated the increase of 36:1-, 40:5-, 40:6-diacyl-PA, suggesting that DGK IL-2-dependently and selectively generated these diacyl-PA species.
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Key Words
- DGK, diacylglycerol kinase
- DMEM, Dulbecco's modified Eagle's medium
- Diacylglycerol kinase
- ESI, electrospray ionization
- FBS, fetal bovine serum
- IL-2, interleukin-2
- Interleukin-2
- LC, liquid chromatography
- Liquid chromatography/electrospray-ionization mass spectrometry
- MEF, mouse embryonic fibroblast
- MS, mass spectrometry
- PA, phosphatidic acid
- PLD, phospholipase D.
- Phosphatidic acid
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Affiliation(s)
- Satoru Mizuno
- Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
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Kawaguchi M, Valencia JC, Namiki T, Suzuki T, Hearing VJ. Diacylglycerol kinase regulates tyrosinase expression and function in human melanocytes. J Invest Dermatol 2012; 132:2791-9. [PMID: 22895365 PMCID: PMC3502659 DOI: 10.1038/jid.2012.261] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Diacylglycerol increases the melanin content of human melanocytes in vitro and increases the pigmentation of guinea pig skin in vivo, but the mechanism(s) underlying those effects remain unknown. In this study, we characterized the role of diacylglycerol kinase (DGK), which phosphorylates diacylglycerol to generate phosphatidic acid, in the regulation of pigmentation. Ten isoforms of DGK have been identified, and we show that DGKζ is the most abundant isoform expressed by human melanocytic cells. Melanin content, tyrosinase activity and tyrosinase protein levels were significantly reduced by a DGK inhibitor, but tyrosinase and MITF mRNA levels were not changed by that inhibition, and there were no effects on the expression of other melanogenesis-related proteins. Isoform-specific siRNAs showed that knockdown of DGKζ decreased melanin content and tyrosinase expression in melanocytic cells. Over-expression of DGKζ increased tyrosinase protein levels, but did not increase tyrosinase mRNA levels. Glycosidase digestion revealed that inhibition of DGK reduced only the mature form of tyrosinase and the decrease of tyrosinase resulting from DGK inhibition could be blocked partially by protease inhibitors. These results suggest that DGK regulates melanogenesis via modulation of the post-translational processing of tyrosinase, which may be related with the protein degradation machinery.
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Affiliation(s)
- Masakazu Kawaguchi
- Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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Rainero E, Caswell PT, Muller PAJ, Grindlay J, McCaffrey MW, Zhang Q, Wakelam MJO, Vousden KH, Graziani A, Norman JC. Diacylglycerol kinase α controls RCP-dependent integrin trafficking to promote invasive migration. ACTA ACUST UNITED AC 2012; 196:277-95. [PMID: 22270919 PMCID: PMC3265946 DOI: 10.1083/jcb.201109112] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Phosphatidic acid generation by DGK-α is essential for the localization of Rab11-coupling protein to invasive pseudopods and subsequent invasive migration by tumor cells. Inhibition of αvβ3 integrin or expression of oncogenic mutants of p53 promote invasive cell migration by enhancing endosomal recycling of α5β1 integrin under control of the Rab11 effector Rab-coupling protein (RCP). In this paper, we show that diacylglycerol kinase α (DGK-α), which phosphorylates diacylglycerol to phosphatidic acid (PA), was required for RCP to be mobilized to and tethered at the tips of invasive pseudopods and to allow RCP-dependent α5β1 recycling and the resulting invasiveness of tumor cells. Expression of a constitutive-active mutant of DGK-α drove RCP-dependent invasion in the absence of mutant p53 expression or αvβ3 inhibition, and conversely, an RCP mutant lacking the PA-binding C2 domain was not capable of being tethered at pseudopod tips. These data demonstrate that generation of PA downstream of DGK-α is essential to connect expression of mutant p53s or inhibition of αvβ3 to RCP and for this Rab11 effector to drive the trafficking of α5β1 that is required for tumor cell invasion through three-dimensional matrices.
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Affiliation(s)
- Elena Rainero
- Beatson Institute for Cancer Research, G61 1BD Glasgow, Scotland, UK
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Marumo M, Nakano T, Takeda Y, Goto K, Wakabayashi I. Inhibition of thrombin-induced Ca²⁺ influx in platelets by R59949, an inhibitor of diacylglycerol kinase. ACTA ACUST UNITED AC 2012; 64:855-61. [PMID: 22571264 DOI: 10.1111/j.2042-7158.2012.01485.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVES The aim of this study was to determine whether diacylglycerol kinase (DGK) is involved in transplasmalemmal Ca²⁺ influx of platelets. METHODS Effects of R59949, an inhibitor of diacylglycerol kinase, on intracellular Ca²⁺ concentration ([Ca²⁺](i) ) and mRNA expression of DGK isozymes were investigated using washed human platelet suspensions. KEY FINDINGS Thrombin-induced increase in [Ca²⁺](i) was significantly inhibited by pretreatment of platelets with R59949, while thapsigargin-induced increase in [Ca²⁺](i) was comparable in platelets with and without R59949 pretreatment. Thapsigargin-induced increase in [Ca²⁺](i) was markedly attenuated in the presence of SKF-96365. In the presence of SKF-96365, thrombin-induced increase in [Ca²⁺](i) was significantly attenuated, and additional treatment with R59949 caused a further decrease in [Ca²⁺](i) . Pretreatment of platelets with 1-butanol significantly attenuated thrombin-induced increase in [Ca²⁺](i) , while thrombin-induced increase in [Ca²⁺](i) was augmented in the presence of propranolol. mRNA expression of DGK-α and DGK-γ, which are known to be inhibited by R59949, in platelets was confirmed by RT-PCR analysis. CONCLUSIONS R59949 inhibited a store-depletion-insensitive component of transplasmalemmal Ca²⁺ entry induced by thrombin, while store-operated Ca²⁺ entry was not affected by R59949. The results of this study suggest that phosphatidic acid is involved in thrombin-induced Ca²⁺ influx of platelets.
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Affiliation(s)
- Mikio Marumo
- Department of Environmental and Preventive Medicine, Hyogo College of Medicine, Mukogawa-cho, Nishinomiya, Hyogo, Japan
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Holden NJ, Savage COS, Young SP, Wakelam MJ, Harper L, Williams JM. A dual role for diacylglycerol kinase generated phosphatidic acid in autoantibody-induced neutrophil exocytosis. Mol Med 2011; 17:1242-52. [PMID: 21833457 DOI: 10.2119/molmed.2011.00028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Accepted: 08/05/2011] [Indexed: 01/12/2023] Open
Abstract
Dysregulated release of neutrophil azurophilic granules causes increased tissue damage and amplified inflammation during autoimmune disease. Antineutrophil cytoplasmic antibodies (ANCAs) are implicated in the pathogenesis of small vessel vasculitis and promote adhesion and exocytosis in neutrophils. ANCAs activate specific signal transduction pathways in neutrophils that have the potential to be modulated therapeutically to prevent neutrophil activation by ANCAs. We have investigated a role for diacylglycerol kinase (DGK) and its downstream product phosphatidic acid (PA) in ANCA-induced neutrophil exocytosis. Neutrophils incubated with the DGK inhibitor R59022, before treatment with ANCAs, exhibited a reduced capacity to release their azurophilic granules, demonstrated by a component release assay and flow cytometry. PA restored azurophilic granule release in DGK-inhibited neutrophils. Confocal microscopy revealed that R59022 did not inhibit translocation of granules, indicating a role for DGK during the process of granule fusion at the plasma membrane. In investigating possible mechanisms by which PA promotes neutrophil exocytosis, we demonstrated that exocytosis can only be restored in R59022-treated cells through simultaneous modulation of membrane fusion and increasing cytosolic calcium. PA and its associated pathways may represent viable drug targets to reduce tissue injury associated with ANCA-associated vasculitic diseases and other neutrophilic inflammatory disorders.
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Affiliation(s)
- Neil J Holden
- Renal Immunobiology, School of Immunity and Infection, University of Birmingham, Birmingham, United Kingdom
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Inhibitors of diacylglycerol metabolism reduce time to the onset of glutamate release potentation by mGlu7 receptors. Neurosci Lett 2011; 500:144-7. [DOI: 10.1016/j.neulet.2011.06.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 04/29/2011] [Accepted: 06/11/2011] [Indexed: 12/22/2022]
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