1
|
Kaneko YK, Morioka A, Sano M, Tashiro M, Watanabe N, Kasahara N, Nojiri M, Ishiwatari C, Ichinose K, Minami A, Suzuki T, Yamaguchi M, Kimura T, Ishikawa T. Asymmetric dimethylarginine accumulation under hyperglycemia facilitates β-cell apoptosis via inhibiting nitric oxide production. Biochem Biophys Res Commun 2022; 637:108-116. [DOI: 10.1016/j.bbrc.2022.11.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 10/28/2022] [Accepted: 11/06/2022] [Indexed: 11/10/2022]
|
2
|
The Role of Diacylglycerol Kinase in the Amelioration of Diabetic Nephropathy. Molecules 2022; 27:molecules27206784. [PMID: 36296376 PMCID: PMC9607625 DOI: 10.3390/molecules27206784] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 10/05/2022] [Accepted: 10/07/2022] [Indexed: 12/02/2022] Open
Abstract
The drastic increase in the number of patients with diabetes and its complications is a global issue. Diabetic nephropathy, the leading cause of chronic kidney disease, significantly affects patients’ quality of life and medical expenses. Furthermore, there are limited drugs for treating diabetic nephropathy patients. Impaired lipid signaling, especially abnormal protein kinase C (PKC) activation by de novo-synthesized diacylglycerol (DG) under high blood glucose, is one of the causes of diabetic nephropathy. DG kinase (DGK) is an enzyme that phosphorylates DG and generates phosphatidic acid, i.e., DGK can inhibit PKC activation under diabetic conditions. Indeed, it has been proven that DGK activation ameliorates diabetic nephropathy. In this review, we summarize the involvement of PKC and DGK in diabetic nephropathy as therapeutic targets, and its mechanisms, by referring to our recent study.
Collapse
|
3
|
Su C, Gao L, May CL, Pippin JA, Boehm K, Lee M, Liu C, Pahl MC, Golson ML, Naji A, Grant SFA, Wells AD, Kaestner KH. 3D chromatin maps of the human pancreas reveal lineage-specific regulatory architecture of T2D risk. Cell Metab 2022; 34:1394-1409.e4. [PMID: 36070683 PMCID: PMC9664375 DOI: 10.1016/j.cmet.2022.08.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 06/03/2022] [Accepted: 08/17/2022] [Indexed: 12/20/2022]
Abstract
Three-dimensional (3D) chromatin organization maps help dissect cell-type-specific gene regulatory programs. Furthermore, 3D chromatin maps contribute to elucidating the pathogenesis of complex genetic diseases by connecting distal regulatory regions and genetic risk variants to their respective target genes. To understand the cell-type-specific regulatory architecture of diabetes risk, we generated transcriptomic and 3D epigenomic profiles of human pancreatic acinar, alpha, and beta cells using single-cell RNA-seq, single-cell ATAC-seq, and high-resolution Hi-C of sorted cells. Comparisons of these profiles revealed differential A/B (open/closed) chromatin compartmentalization, chromatin looping, and transcriptional factor-mediated control of cell-type-specific gene regulatory programs. We identified a total of 4,750 putative causal-variant-to-target-gene pairs at 194 type 2 diabetes GWAS signals using pancreatic 3D chromatin maps. We found that the connections between candidate causal variants and their putative target effector genes are cell-type stratified and emphasize previously underappreciated roles for alpha and acinar cells in diabetes pathogenesis.
Collapse
Affiliation(s)
- Chun Su
- Division of Human Genetics and Endocrinology & Diabetes, The Children's Hospital of Philadelphia, Philadelphia, PA, USA; Center for Spatial and Functional Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Long Gao
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Catherine L May
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - James A Pippin
- Division of Human Genetics and Endocrinology & Diabetes, The Children's Hospital of Philadelphia, Philadelphia, PA, USA; Center for Spatial and Functional Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Keith Boehm
- Division of Human Genetics and Endocrinology & Diabetes, The Children's Hospital of Philadelphia, Philadelphia, PA, USA; Center for Spatial and Functional Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Michelle Lee
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Chengyang Liu
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA; Department of Surgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Matthew C Pahl
- Division of Human Genetics and Endocrinology & Diabetes, The Children's Hospital of Philadelphia, Philadelphia, PA, USA; Center for Spatial and Functional Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Maria L Golson
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Ali Naji
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA; Department of Surgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Struan F A Grant
- Division of Human Genetics and Endocrinology & Diabetes, The Children's Hospital of Philadelphia, Philadelphia, PA, USA; Center for Spatial and Functional Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA; Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA; Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
| | - Andrew D Wells
- Center for Spatial and Functional Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA; Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA; Institute for Immunology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
| | - Klaus H Kaestner
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
4
|
Kaneko YK, Sawatani T, Ishikawa T. Involvement of Diacylglycerol Kinase on the Regulation of Insulin Secretion in Pancreatic β-Cells during Type 2 Diabetes. YAKUGAKU ZASSHI 2022; 142:457-463. [PMID: 35491149 DOI: 10.1248/yakushi.21-00176-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Depression of lipid metabolism in β-cells has been indicated to be one of the causes of impaired insulin secretion in type 2 diabetes. Diacylglycerol (DAG) is an important lipid mediator and is known to regulate insulin secretion in pancreatic β-cells. Intracellular DAG accumulation is involved in β-cell dysfunction in the pathogenesis of type 2 diabetes; thus, the regulation of intracellular DAG levels is likely important for maintaining the β-cell function. We focused on diacylglycerol kinases (DGKs), which strictly regulate intracellular DAG levels, and analyzed the function of type I DGKs (DGKα, γ), which are activated by intracellular Ca2+ and expressed in the cytoplasm, in β-cells. The suppression of the DGKα and γ expression decreased the insulin secretory response, and the decreased expression of DGKα and γ was observed in islets of diabetic model mice. In the pancreatic β-cell line MIN6, 1 μM R59949 (a type I DGK inhibitor) and 10 μM DiC8 (a cell permeable DAG analog) enhanced glucose-induced [Ca2+]i oscillation in a PKC-dependent manner, while 10 μM R59949 and 100 μM DiC8 suppressed [Ca2+]i oscillation and voltage-dependent Ca2+ channel activity in a PKC-independent manner. These results suggest that the intracellular accumulation of DAG by the loss of the DGKα and γ functions regulates insulin secretion in a dual manner depending on the degree of DAG accumulation. The regulation of the insulin secretory response through DAG metabolism by type I DGKs may change depending on the degree of progression of type 2 diabetes.
Collapse
Affiliation(s)
- Yukiko K. Kaneko
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka
| | - Toshiaki Sawatani
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka
| | - Tomohisa Ishikawa
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka
| |
Collapse
|
5
|
Sato T, Ishiwatari C, Kaneko YK, Ishikawa Y, Kimura Y, Watanabe N, Aoshima I, Matsuda Y, Nakayama T, Chiba R, Fujinuki T, Iwata K, Lu Q, Usuki T, Sakane F, Ishikawa T. Diacylglycerol kinase δ functions as a proliferation suppressor in pancreatic β-cells. FASEB J 2021; 35:e21420. [PMID: 33774855 DOI: 10.1096/fj.202001279rr] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 01/19/2021] [Accepted: 01/21/2021] [Indexed: 11/11/2022]
Abstract
Although an aberrant reduction in pancreatic β-cell mass contributes to the pathogenesis of diabetes, the mechanism underlying the regulation of β-cell mass is poorly understood. Here, we show that diacylglycerol kinase δ (DGKδ) is a key enzyme in the regulation of β-cell mass. DGKδ expression was detected in the nucleus of β-cells. We developed β-cell-specific DGKδ knockout (βDGKδ KO) mice, which showed lower blood glucose, higher plasma insulin levels, and better glucose tolerance compared to control mice. Moreover, an increased number of small islets and Ki-67-positive islet cells, as well as elevated cyclin B1 expression in the islets, were detected in the pancreas of βDGKδ KO mice. DGKδ knockdown in the β-cell line MIN6 induced significant increases in bromodeoxyuridine (BrdU) incorporation and cyclin B1 expression. Finally, we confirmed that streptozotocin-induced hyperglycemia and β-cell loss were alleviated in βDGKδ KO mice. Thus, suppressing the expression or enzymatic activity of DGKδ that functions as a suppressor of β-cell proliferation could be a novel therapeutic approach to increase β-cell mass for the treatment of diabetes.
Collapse
Affiliation(s)
- Taiji Sato
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Chihiro Ishiwatari
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Yukiko K Kaneko
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Yoko Ishikawa
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Yuki Kimura
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Naoya Watanabe
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Ikumi Aoshima
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Yukari Matsuda
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Takahiro Nakayama
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Rina Chiba
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Takahiro Fujinuki
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Kai Iwata
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
| | - Qiang Lu
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
| | - Takako Usuki
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
| | - Fumio Sakane
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
| | - Tomohisa Ishikawa
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| |
Collapse
|
6
|
MicroRNA Sequences Modulated by Beta Cell Lipid Metabolism: Implications for Type 2 Diabetes Mellitus. BIOLOGY 2021; 10:biology10060534. [PMID: 34203703 PMCID: PMC8232095 DOI: 10.3390/biology10060534] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 06/08/2021] [Accepted: 06/09/2021] [Indexed: 12/23/2022]
Abstract
Alterations in lipid metabolism within beta cells and islets contributes to dysfunction and apoptosis of beta cells, leading to loss of insulin secretion and the onset of type 2 diabetes. Over the last decade, there has been an explosion of interest in understanding the landscape of gene expression which influences beta cell function, including the importance of small non-coding microRNA sequences in this context. This review sought to identify the microRNA sequences regulated by metabolic challenges in beta cells and islets, their targets, highlight their function and assess their possible relevance as biomarkers of disease progression in diabetic individuals. Predictive analysis was used to explore networks of genes targeted by these microRNA sequences, which may offer new therapeutic strategies to protect beta cell function and delay the onset of type 2 diabetes.
Collapse
|
7
|
Beyond Lipid Signaling: Pleiotropic Effects of Diacylglycerol Kinases in Cellular Signaling. Int J Mol Sci 2020; 21:ijms21186861. [PMID: 32962151 PMCID: PMC7554708 DOI: 10.3390/ijms21186861] [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] [Received: 08/26/2020] [Revised: 09/11/2020] [Accepted: 09/16/2020] [Indexed: 12/13/2022] Open
Abstract
The diacylglycerol kinase family, which can attenuate diacylglycerol signaling and activate phosphatidic acid signaling, regulates various signaling transductions in the mammalian cells. Studies on the regulation of diacylglycerol and phosphatidic acid levels by various enzymes, the identification and characterization of various diacylglycerol and phosphatidic acid-regulated proteins, and the overlap of different diacylglycerol and phosphatidic acid metabolic and signaling processes have revealed the complex and non-redundant roles of diacylglycerol kinases in regulating multiple biochemical and biological networks. In this review article, we summarized recent progress in the complex and non-redundant roles of diacylglycerol kinases, which is expected to aid in restoring dysregulated biochemical and biological networks in various pathological conditions at the bed side.
Collapse
|
8
|
Minami A, Fujita Y, Shimba S, Shiratori M, Kaneko YK, Sawatani T, Otsubo T, Ikeda K, Kanazawa H, Mikami Y, Sekita R, Kurebayashi Y, Takahashi T, Miyagi T, Ishikawa T, Suzuki T. The sialidase inhibitor 2,3-dehydro-2-deoxy-N-acetylneuraminic acid is a glucose-dependent potentiator of insulin secretion. Sci Rep 2020; 10:5198. [PMID: 32251344 PMCID: PMC7089948 DOI: 10.1038/s41598-020-62203-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 03/06/2020] [Indexed: 12/12/2022] Open
Abstract
Sialidase cleaves sialic acid residues from a sialoglycoconjugate: oligosaccharides, glycolipids and glycoproteins that contain sialic acid. Histochemical imaging of the mouse pancreas using a benzothiazolylphenol-based sialic acid derivative (BTP3-Neu5Ac), a highly sensitive histochemical imaging probe used to assess sialidase activity, showed that pancreatic islets have intense sialidase activity. The sialidase inhibitor 2,3-dehydro-2-deoxy-N-acetylneuraminic acid (DANA) remarkably enhances glutamate release from hippocampal neurons. Since there are many similar processes between synaptic vesicle exocytosis and secretory granule exocytosis, we investigated the effect of DANA on insulin release from β-cells. Insulin release was induced in INS-1D cells by treatment with 8.3 mM glucose, and the release was enhanced by treatment with DANA. In a mouse intraperitoneal glucose tolerance test, the increase in serum insulin levels was enhanced by intravenous injection with DANA. However, under fasting conditions, insulin release was not enhanced by treatment with DANA. Calcium oscillations induced by 8.3 mM glucose treatment of INS-1D cells were not affected by DANA. Blood insulin levels in sialidase isozyme Neu3-deficient mice were significantly higher than those in WT mice under ad libitum feeding conditions, but the levels were not different under fasting conditions. These results indicate that DANA is a glucose-dependent potentiator of insulin secretion. The sialidase inhibitor may be useful for anti-diabetic treatment with a low risk of hypoglycemia.
Collapse
Affiliation(s)
- Akira Minami
- Department of Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, 422-8526, Japan.
| | - Yuka Fujita
- Department of Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, 422-8526, Japan
| | - Sumika Shimba
- Department of Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, 422-8526, Japan
| | - Mako Shiratori
- Department of Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, 422-8526, Japan
| | - Yukiko K Kaneko
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, 422-8526, Japan
| | - Toshiaki Sawatani
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, 422-8526, Japan
| | - Tadamune Otsubo
- Department of Organic Chemistry, School of Pharmaceutical Sciences, Hiroshima International University, Hiroshima, 737-0112, Japan
| | - Kiyoshi Ikeda
- Department of Organic Chemistry, School of Pharmaceutical Sciences, Hiroshima International University, Hiroshima, 737-0112, Japan
| | - Hiroaki Kanazawa
- Department of Functional Anatomy, School of Nursing, University of Shizuoka, Shizuoka, 422-8526, Japan
| | - Yasuyo Mikami
- Department of Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, 422-8526, Japan
| | - Risa Sekita
- Department of Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, 422-8526, Japan
| | - Yuuki Kurebayashi
- Department of Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, 422-8526, Japan
| | - Tadanobu Takahashi
- Department of Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, 422-8526, Japan
| | - Taeko Miyagi
- Miyagi Cancer Center Research Institute, Natori, 981-1293, Japan
| | - Tomohisa Ishikawa
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, 422-8526, Japan
| | - Takashi Suzuki
- Department of Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, 422-8526, Japan.
| |
Collapse
|
9
|
Sawatani T, Kaneko YK, Ishikawa T. Dual effect of reduced type I diacylglycerol kinase activity on insulin secretion from MIN6 β-cells. J Pharmacol Sci 2019; 140:178-186. [PMID: 31279581 DOI: 10.1016/j.jphs.2019.06.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 05/03/2019] [Accepted: 06/11/2019] [Indexed: 02/07/2023] Open
Abstract
The role of type I diacylglycerol kinases (DGKs) in the regulation of insulin secretion was investigated in MIN6 β-cells. In intracellular Ca2+ concentration ([Ca2+]i) measurement experiments, 1 μM R59949, a type I DGK inhibitor, and 10 μM DiC8, a diacylglycerol (DAG) analog, amplified 22.2 mM glucose-induced [Ca2+]i oscillations in a protein kinase C (PKC)-dependent manner, whereas 10 μM R59949 and 100 μM DiC8 decreased [Ca2+]i independent of PKC. High concentrations of R59949 and DiC8 attenuated voltage-dependent Ca2+ channel currents. According to these results, 22.2 mM glucose-stimulated insulin secretion (GSIS) was potentiated by 1 μM R59949 but suppressed by 10 μM of the same. The DGKα inhibitor R59022 showed a similar dual effect. Conversely, DiC8 at 10 and 100 μM potentiated GSIS, although 100 μM DiC8 decreased [Ca2+]i. These results suggest that DAG accumulated through declined type I DGK activity shows a dual effect on insulin secretion depending on the degree of accumulation; a mild DAG accumulation induces a PKC-dependent stimulatory effect on insulin secretion, whereas an excessive DAG accumulation suppresses it in a PKC-independent manner, possibly via attenuation of VDCC activity.
Collapse
Affiliation(s)
- Toshiaki Sawatani
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka City, Shizuoka, 422-8526, Japan
| | - Yukiko K Kaneko
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka City, Shizuoka, 422-8526, Japan.
| | - Tomohisa Ishikawa
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka City, Shizuoka, 422-8526, Japan
| |
Collapse
|
10
|
Sawatani T, Kaneko YK, Doutsu I, Ogawa A, Ishikawa T. TRPV2 channels mediate insulin secretion induced by cell swelling in mouse pancreatic β-cells. Am J Physiol Cell Physiol 2019; 316:C434-C443. [PMID: 30649920 DOI: 10.1152/ajpcell.00210.2017] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
β-Cell swelling induces membrane depolarization, which has been suggested to be caused at least partly by the activation of cation channels. Here, we show the identification of the cation channels. In isolated mouse pancreatic β-cells, the exposure to 30% hypotonic solution elicited an increase in cytosolic Ca2+ concentration ([Ca2+]c). The [Ca2+]c elevation was partially inhibited by ruthenium red, a blocker of several Ca2+-permeable channels including transient receptor potential vanilloid receptors [transient receptor potential cation channel subfamily V (TRPV)], and by nicardipine, but not by the depletion of intracellular Ca2+ stores with thapsigargin and caffeine. The hypotonic stimulation also increased insulin secretion from isolated mouse islets, which was significantly suppressed by ruthenium red. Expression of TRPV2 and TRPV4 was confirmed in mouse pancreatic islets and the MIN6 β-cell line by RT-PCR, Western blot, and immunohistochemical analyses. However, neither 4α-phorbol 12,13-didecanoate nor GSK1016790A, TRPV4 activators, showed any apparent effect on [Ca2+]c in isolated mouse β-cells or in MIN6 cells. In contrast, probenecid, a TRPV2 activator, induced an increase in [Ca2+]c in MIN6 cells, which was attenuated by ruthenium red. Moreover, the [Ca2+]c elevation induced by 30% hypotonic stimulation was significantly reduced by knockdown of TRPV2 with siRNA and by tranilast, a TRPV2 inhibitor. The knockdown of TRPV2 also decreased insulin secretion induced by the hypotonic stimulation. In addition, glucose-stimulated insulin secretion was also significantly reduced in the TRPV2-knockdown MIN6 cells. These results suggest that osmotic cell swelling activates TRPV2 in mouse β-cells, thereby causing membrane depolarization and subsequent activation of voltage-dependent Ca2+ channels and insulin secretion.
Collapse
Affiliation(s)
- Toshiaki Sawatani
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka City, Japan
| | - Yukiko K Kaneko
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka City, Japan
| | - Isao Doutsu
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka City, Japan
| | - Ai Ogawa
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka City, Japan
| | - Tomohisa Ishikawa
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka City, Japan
| |
Collapse
|
11
|
Xie B, Nguyen PM, Idevall-Hagren O. Feedback regulation of insulin secretion by extended synaptotagmin-1. FASEB J 2018; 33:4716-4728. [PMID: 30589572 DOI: 10.1096/fj.201801878r] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Endoplasmic reticulum (ER)-plasma membrane (PM) contacts are dynamic structures with important roles in the regulation of calcium (Ca2+) and lipid homeostasis. The extended synaptotagmins (E-Syts) are ER-localized lipid transport proteins that interact with PM phosphatidylinositol 4,5-bisphosphate in a Ca2+-dependent manner. E-Syts bidirectionally transfer glycerolipids, including diacylglycerol (DAG), between the 2 juxtaposed membranes, but the biologic significance of this transport is still unclear. Using insulin-secreting cells and live-cell imaging, we now show that Ca2+-triggered exocytosis of insulin granules is followed, in sequence, by PM DAG formation and E-Syt1 recruitment. E-Syt1 counteracted the depolarization-induced DAG formation through a mechanism that required both voltage-dependent Ca2+ influx and Ca2+ release from the ER. E-Syt1 knockdown resulted in prolonged accumulation of DAG in the PM, resulting in increased glucose-stimulated insulin secretion. We conclude that Ca2+-triggered exocytosis is temporally coupled to Ca2+-triggered E-Syt1 PM recruitment and removal of DAG to negatively regulate the same process.-Xie, B., Nguyen, P. M., Idevall-Hagren, O. Feedback regulation of insulin secretion by extended synaptotagmin-1.
Collapse
Affiliation(s)
- Beichen Xie
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Phuoc My Nguyen
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | | |
Collapse
|
12
|
Trinh I, Gluscencova OB, Boulianne GL. An in vivo screen for neuronal genes involved in obesity identifies Diacylglycerol kinase as a regulator of insulin secretion. Mol Metab 2018; 19:13-23. [PMID: 30389349 PMCID: PMC6323187 DOI: 10.1016/j.molmet.2018.10.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 09/26/2018] [Accepted: 10/15/2018] [Indexed: 12/31/2022] Open
Abstract
Objective Obesity is a complex disorder involving many genetic and environmental factors that are required to maintain energy homeostasis. While studies in human populations have led to significant progress in the generation of an obesity gene map and broadened our understanding of the genetic basis of common obesity, there is still a large portion of heritability and etiology that remains unknown. Here, we have used the genetically tractable fruit fly, Drosophila melanogaster, to identify genes/pathways that function in the nervous system to regulate energy balance. Methods We performed an in vivo RNAi screen in Drosophila neurons and assayed for obese or lean phenotypes by measuring changes in levels of stored fats (in the form of triacylglycerides or TAG). Three rounds of screening were performed to verify the reproducibility and specificity of the adiposity phenotypes. Genes that produced >25% increase in TAG (206 in total) underwent a second round of screening to verify their effect on TAG levels by retesting the same RNAi line to validate the phenotype. All remaining hits were screened a third time by testing the TAG levels of additional RNAi lines against the genes of interest to rule out any off-target effects. Results We identified 24 genes including 20 genes that have not been previously associated with energy homeostasis. One identified hit, Diacylglycerol kinase (Dgk), has mammalian homologues that have been implicated in genome-wide association studies for metabolic defects. Downregulation of neuronal Dgk levels increases TAG and carbohydrate levels and these phenotypes can be recapitulated by reducing Dgk levels specifically within the insulin-producing cells that secrete Drosophila insulin-like peptides (dILPs). Conversely, overexpression of kinase-dead Dgk, but not wild-type, decreased circulating dILP2 and dILP5 levels resulting in lower insulin signalling activity. Despite having higher circulating dILP levels, Dgk RNAi flies have decreased pathway activity suggesting that they are insulin-resistant. Conclusion Altogether, we have identified several genes that act within the CNS to regulate energy homeostasis. One of these, Dgk, acts within the insulin-producing cells to regulate the secretion of dILPs and energy homeostasis in Drosophila. RNAi screen in neurons identifies 24 regulators of energy homeostasis. One of the hits, Dgk, affects lipid and carbohydrate homeostasis. Dgk acts within the IPCs to regulate dILP secretion and insulin signalling activity.
Collapse
Affiliation(s)
- Irene Trinh
- Department of Molecular Genetics, University of Toronto, Toronto, M5S 1A8, Canada; Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Peter Gilgan Center for Research and Learning, 686 Bay Street, Toronto, M5G 0A6, Canada.
| | - Oxana B Gluscencova
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Peter Gilgan Center for Research and Learning, 686 Bay Street, Toronto, M5G 0A6, Canada.
| | - Gabrielle L Boulianne
- Department of Molecular Genetics, University of Toronto, Toronto, M5S 1A8, Canada; Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Peter Gilgan Center for Research and Learning, 686 Bay Street, Toronto, M5G 0A6, Canada.
| |
Collapse
|
13
|
Sakane F, Mizuno S, Takahashi D, Sakai H. Where do substrates of diacylglycerol kinases come from? Diacylglycerol kinases utilize diacylglycerol species supplied from phosphatidylinositol turnover-independent pathways. Adv Biol Regul 2018; 67:101-108. [PMID: 28918129 DOI: 10.1016/j.jbior.2017.09.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 09/08/2017] [Accepted: 09/08/2017] [Indexed: 06/07/2023]
Abstract
Diacylglycerol kinase (DGK) phosphorylates diacylglycerol (DG) to produce phosphatidic acid (PA). Mammalian DGK comprises ten isozymes (α-κ) and regulates a wide variety of physiological and pathological events, such as cancer, type II diabetes, neuronal disorders and immune responses. DG and PA consist of various molecular species that have different acyl chains at the sn-1 and sn-2 positions, and consequently, mammalian cells contain at least 50 structurally distinct DG/PA species. Because DGK is one of the components of phosphatidylinositol (PI) turnover, the generally accepted dogma is that all DGK isozymes utilize 18:0/20:4-DG derived from PI turnover. We recently established a specific liquid chromatography-mass spectrometry method to analyze which PA species were generated by DGK isozymes in a cell stimulation-dependent manner. Interestingly, we determined that DGKδ, which is closely related to the pathogenesis of type II diabetes, preferentially utilized 14:0/16:0-, 14:0/16:1-, 16:0/16:0-, 16:0/16:1-, 16:0/18:0- and 16:0/18:1-DG species (X:Y = the total number of carbon atoms: the total number of double bonds) supplied from the phosphatidylcholine-specific phospholipase C pathway, but not 18:0/20:4-DG, in high glucose-stimulated C2C12 myoblasts. Moreover, DGKα mainly consumed 14:0/16:0-, 16:0/18:1-, 18:0/18:1- and 18:1/18:1-DG species during cell proliferation in AKI melanoma cells. Furthermore, we found that 16:0/16:0-PA was specifically produced by DGKζ in Neuro-2a cells during retinoic acid- and serum starvation-induced neuronal differentiation. These results indicate that DGK isozymes utilize a variety of DG molecular species derived from PI turnover-independent pathways as substrates in different stimuli and cells. DGK isozymes phosphorylate various DG species to generate various PA species. It was revealed that the modes of activation of conventional and novel protein kinase isoforms by DG molecular species varied considerably. However, PA species-selective binding proteins have not been found to date. Therefore, we next attempted to identify PA species-selective binding proteins from the mouse brain and identified α-synuclein, which has causal links to Parkinson's disease. Intriguingly, we determined that among phospholipids, including several PA species (16:0/16:0-PA, 16:0/18:1-PA, 18:1/18:1-PA, 18:0/18:0-PA and 18:0/20:4-PA); 18:1/18:1-PA was the most strongly bound PA to α-synuclein. Moreover, 18:1/18:1-PA strongly enhanced secondary structural changes from the random coil form to the α-helix form and generated a multimeric and proteinase K-resistant α-synuclein protein. In contrast with the dogma described above, our recent studies strongly suggest that PI turnover-derived DG species and also various DG species derived from PI turnover-independent pathways are utilized by DGK isozymes. DG species supplied from distinct pathways may be utilized by DGK isozymes based on different stimuli present in different types of cells, and individual PA molecular species would have specific targets and exert their own physiological functions.
Collapse
Affiliation(s)
- Fumio Sakane
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan.
| | - Satoru Mizuno
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
| | - Daisuke Takahashi
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
| | - Hiromichi Sakai
- Department of Biosignaling and Radioisotope Experiment, Interdisciplinary Center for Science Research, Organization for Research and Academic Information, Shimane University, Izumo, Japan
| |
Collapse
|
14
|
Nascimento EBM, Mannerås-Holm L, Chibalin AV, Björnholm M, Zierath JR. Diacylglycerol kinase α deficiency alters inflammation markers in adipose tissue in response to a high-fat diet. J Lipid Res 2017; 59:273-282. [PMID: 29233919 DOI: 10.1194/jlr.m079517] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 12/06/2017] [Indexed: 12/20/2022] Open
Abstract
Conversion of diacylglycerol to phosphatidic acid is mediated by diacylglycerol kinases (DGKs), with DGKα specifically linked to adaptive immune responses. We determined the role of DGKα in obesity and inflammatory responses to a high-fat diet (HFD). DGKα KO and WT littermates were either a) chow-fed, b) HFD-fed for 12 weeks (Long-Term HFD), or c) HFD-fed for 3 days (Acute HFD). Body weight/composition, oxygen consumption, food intake, and glucose tolerance was unaltered between chow-fed DGKα KO and WT mice. Insulin concentration during the intraperitoneal glucose tolerance (IPGT) test was elevated in chow-fed DGKα KO mice, suggesting mild insulin resistance. Insulin concentration during the IPGT test was reduced in Long-Term HFD-fed DGKα KO mice, suggesting a mild enhancement in insulin sensitivity. Acute HFD increased hormone sensitive lipase protein abundance and altered expression of interleukin 1β mRNA, an inflammatory marker in perigonadal adipose tissue of DGKα KO mice. In conclusion, DGKα ablation is associated with mild alterations in insulin sensitivity. However, DGKα is dispensable for whole body insulin-mediated glucose uptake, hepatic glucose production, and energy homeostasis. Our results suggest DGKα aids in modulating the early immune response of adipose tissue following an acute exposure to HFD, possibly through modulation of acute T-cell action.
Collapse
Affiliation(s)
| | - Louise Mannerås-Holm
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Alexander V Chibalin
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Marie Björnholm
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Juleen R Zierath
- Department of Physiology and Pharmacology Karolinska Institutet, Stockholm, Sweden .,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
15
|
Diacylglycerol Kinase alpha is Involved in the Vitamin E-Induced Amelioration of Diabetic Nephropathy in Mice. Sci Rep 2017; 7:2597. [PMID: 28572624 PMCID: PMC5453949 DOI: 10.1038/s41598-017-02354-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 04/10/2017] [Indexed: 02/05/2023] Open
Abstract
Diabetic nephropathy (DN) is one of vascular complications of diabetes and is caused by abnormal protein kinase C activation as a result of increased diacylglycerol (DG) production in diabetic hyperglycaemia. Diacylglycerol kinase (DGK) converts DG into phosphatidic acid. Therefore, it is expected that the activation of DGK would ameliorate DN. Indeed, it has been reported that vitamin E (VtE) ameliorates DN in rat by activating DGK, and we recently reported that VtE specifically activates DGKα isoform in vitro. However, whether DGKα is involved in the VtE-induced amelioration of DN in vivo remains unknown. Therefore, we investigated the VtE-induced amelioration of DN in wild-type (DGKα+/+) and DGKα–deficient (DGKα−/−) mice in which diabetes was induced by streptozocin. Several symptoms of DN were ameliorated by VtE treatment in the DGKα+/+ mice but not in the DGKα−/− mice. Moreover, transmission electron microscopy of glomeruli and immunofluorescent staining of glomerular epithelial cells (podocytes) indicated that VtE ameliorates podocyte pathology and prevents podocyte loss in the DGKα+/+ mice but not in the DGKα−/− mice. We showed that VtE can ameliorate DN in mice and that DGKα is involved in the VtE-induced amelioration of DN in vivo, suggesting that DGKα is an attractive therapeutic target for DN.
Collapse
|
16
|
Kaneko YK, Ishikawa T. [Regulation of Lipid Metabolism by Diacylglycerol Kinases in Pancreatic β-cells]. YAKUGAKU ZASSHI 2017; 136:461-5. [PMID: 26935087 DOI: 10.1248/yakushi.15-00246-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The appropriate secretion of insulin from pancreatic β-cells is essential for regulating blood glucose levels. Glucose-stimulated insulin secretion (GSIS) involves the following steps: Glucose uptake by pancreatic β-cells is metabolized to produce ATP. Increased ATP levels result in the closure of ATP-sensitive K(+) (KATP) channels, resulting in membrane depolarization that activates voltage-dependent Ca(2+) channels to subsequently trigger insulin secretion. In addition to this primary mechanism through KATP channels, insulin secretion is regulated by cyclic AMP and diacylglycerol (DAG), which mediate the effects of receptor agonists such as GLP-1 and acetylcholine. Glucose by itself can also increase the levels of these second messengers. Recently, we have shown an obligatory role of diacylglycerol kinase (DGK), an enzyme catalyzing the conversion of DAG to phosphatidic acid, in GSIS. Of the 10 known DGK isoforms, we focused on type-I DGK isoforms (i.e., DGKα, DGKβ, and DGKγ), which are activated by Ca(2+). The protein expression of DGKα and DGKγ was detected in mouse pancreatic islets and the pancreatic β-cell line MIN6. Depletion of these DGKs by a specific inhibitor or siRNA decreased both [Ca(2+)]i and insulin secretion in MIN6 cells. Similar [Ca(2+)]i responses were induced by DiC8, a membrane-permeable DAG analog. These results suggest that DGKα and DGKγ play crucial roles in insulin secretion, and that their depletion impairs insulin secretion through DAG accumulation. In this article, we review the current understanding of the roles of DAG- and DGK-signaling in pancreatic β-cells, and discuss their pathophysiological roles in the progression of type-2 diabetes.
Collapse
Affiliation(s)
- Yukiko K Kaneko
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka
| | | |
Collapse
|
17
|
Liu T, Yu B, Kakino M, Fujimoto H, Ando Y, Hakuno F, Takahashi SI. A novel IRS-1-associated protein, DGKζ regulates GLUT4 translocation in 3T3-L1 adipocytes. Sci Rep 2016; 6:35438. [PMID: 27739494 PMCID: PMC5064357 DOI: 10.1038/srep35438] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 09/29/2016] [Indexed: 12/19/2022] Open
Abstract
Insulin receptor substrates (IRSs) are major targets of insulin receptor tyrosine kinases. Here we identified diacylglycerol kinase zeta (DGKζ) as an IRS-1-associated protein, and examined roles of DGKζ in glucose transporter 4 (GLUT4) translocation to the plasma membrane. When DGKζ was knocked-down in 3T3-L1 adipocytes, insulin-induced GLUT4 translocation was inhibited without affecting other mediators of insulin-dependent signaling. Similarly, knockdown of phosphatidylinositol 4-phosphate 5-kinase 1α (PIP5K1α), which had been reported to interact with DGKζ, also inhibited insulin-induced GLUT4 translocation. Moreover, DGKζ interacted with IRS-1 without insulin stimulation, but insulin stimulation decreased this interaction. Over-expression of sDGKζ (short-form DGKζ), which competed out DGKζ from IRS-1, enhanced GLUT4 translocation without insulin stimulation. Taking these results together with the data showing that cellular PIP5K activity was correlated with GLUT4 translocation ability, we concluded that IRS-1-associated DGKζ prevents GLUT4 translocation in the absence of insulin and that the DGKζ dissociated from IRS-1 by insulin stimulation enhances GLUT4 translocation through PIP5K1α activity.
Collapse
Affiliation(s)
- TingYu Liu
- Departments of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, Japan
| | - BuChin Yu
- Departments of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Mamoru Kakino
- Departments of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Hitoshi Fujimoto
- Departments of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Yasutoshi Ando
- Departments of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Fumihiko Hakuno
- Departments of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Shin-Ichiro Takahashi
- Departments of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, Japan
| |
Collapse
|
18
|
Frank JA, Yushchenko DA, Hodson DJ, Lipstein N, Nagpal J, Rutter GA, Rhee JS, Gottschalk A, Brose N, Schultz C, Trauner D. Photoswitchable diacylglycerols enable optical control of protein kinase C. Nat Chem Biol 2016; 12:755-62. [PMID: 27454932 PMCID: PMC6101201 DOI: 10.1038/nchembio.2141] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 05/16/2016] [Indexed: 01/02/2023]
Abstract
Increased levels of the second messenger lipid diacylglycerol (DAG) induce downstream signaling events including the translocation of C1-domain-containing proteins toward the plasma membrane. Here, we introduce three light-sensitive DAGs, termed PhoDAGs, which feature a photoswitchable acyl chain. The PhoDAGs are inactive in the dark and promote the translocation of proteins that feature C1 domains toward the plasma membrane upon a flash of UV-A light. This effect is quickly reversed after the termination of photostimulation or by irradiation with blue light, permitting the generation of oscillation patterns. Both protein kinase C and Munc13 can thus be put under optical control. PhoDAGs control vesicle release in excitable cells, such as mouse pancreatic islets and hippocampal neurons, and modulate synaptic transmission in Caenorhabditis elegans. As such, the PhoDAGs afford an unprecedented degree of spatiotemporal control and are broadly applicable tools to study DAG signaling.
Collapse
Affiliation(s)
- James Allen Frank
- Department of Chemistry and Center for Integrated Protein Science, Ludwig Maximilians University Munich, Munich, Germany
| | - Dmytro A Yushchenko
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - David J Hodson
- Section of Cell Biology and Functional Genomics, Department of Medicine, Imperial College London, ICTEM, Hammersmith Hospital, London, UK
- Institute of Metabolism and Systems Research (IMSR) and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK
- Centre for Endocrinology, Diabetes and Metabolism (CEDAM), Birmingham Health Partners, Birmingham, UK
| | - Noa Lipstein
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Jatin Nagpal
- Buchmann Institute for Molecular Life Sciences, Goethe University, Frankfurt, Germany
- Institute of Biochemistry, Department for Biochemistry, Chemistry and Pharmacy, Goethe University, Frankfurt, Germany
| | - Guy A Rutter
- Section of Cell Biology and Functional Genomics, Department of Medicine, Imperial College London, ICTEM, Hammersmith Hospital, London, UK
| | - Jeong-Seop Rhee
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Alexander Gottschalk
- Buchmann Institute for Molecular Life Sciences, Goethe University, Frankfurt, Germany
- Institute of Biochemistry, Department for Biochemistry, Chemistry and Pharmacy, Goethe University, Frankfurt, Germany
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Carsten Schultz
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Dirk Trauner
- Department of Chemistry and Center for Integrated Protein Science, Ludwig Maximilians University Munich, Munich, Germany
| |
Collapse
|
19
|
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.
Collapse
|
20
|
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.
Collapse
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
| |
Collapse
|
21
|
Hozumi Y, Nakano T, Tanaka T, Goto K. Localization of diacylglycerol kinase ζ in rat pancreatic islet cells under normal and streptozotocin-induced stress conditions . ACTA ACUST UNITED AC 2016. [DOI: 10.1679/aohc.76.23] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yasukazu Hozumi
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine,
| | - Tomoyuki Nakano
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine,
| | - Toshiaki Tanaka
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine,
| | - Kaoru Goto
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine,
| |
Collapse
|
22
|
Mannerås-Holm L, Kirchner H, Björnholm M, Chibalin AV, Zierath JR. mRNA expression of diacylglycerol kinase isoforms in insulin-sensitive tissues: effects of obesity and insulin resistance. Physiol Rep 2015; 3:3/4/e12372. [PMID: 25847921 PMCID: PMC4425976 DOI: 10.14814/phy2.12372] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Diacylglycerol kinase (DGK) isoforms regulate signal transduction and lipid metabolism. DGKδ deficiency leads to hyperglycemia, peripheral insulin resistance, and metabolic inflexibility. Thus, dysregulation of other DGK isoforms may play a role in metabolic dysfunction. We investigated DGK isoform mRNA expression in extensor digitorum longus (EDL) and soleus muscle, liver as well as subcutaneous and epididymal adipose tissue in C57BL/6J mice and obese and insulin-resistant ob/ob mice. All DGK isoforms, except for DGKκ, were detectable, although with varying mRNA expression. Liver DGK expression was generally lowest, with several isoforms undetectable. In soleus muscle, subcutaneous and epididymal adipose tissue, DGKδ was the most abundant isoform. In EDL muscle, DGKα and DGKζ were the most abundant isoforms. In liver, DGKζ was the most abundant isoform. Comparing obese insulin-resistant ob/ob mice to lean C57BL/6J mice, DGKβ, DGKι, and DGKθ were increased and DGKε expression was decreased in EDL muscle, while DGKβ, DGKη and DGKθ were decreased and DGKδ and DGKι were increased in soleus muscle. In liver, DGKδ and DGKζ expression was increased in ob/ob mice. DGKη was increased in subcutaneous fat, while DGKζ was increased and DGKβ, DGKδ, DGKη and DGKε were decreased in epididymal fat from ob/ob mice. In both adipose tissue depots, DGKα and DGKγ were decreased and DGKι was increased in ob/ob mice. In conclusion, DGK mRNA expression is altered in an isoform- and tissue-dependent manner in obese insulin-resistant ob/ob mice. DGK isoforms likely have divergent functional roles in distinct tissues, which may contribute to metabolic dysfunction.
Collapse
Affiliation(s)
- Louise Mannerås-Holm
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Henriette Kirchner
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Marie Björnholm
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Alexander V Chibalin
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Juleen R Zierath
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
23
|
Kaneko YK, Ishikawa T. Diacylglycerol Signaling Pathway in Pancreatic β-Cells: An Essential Role of Diacylglycerol Kinase in the Regulation of Insulin Secretion. Biol Pharm Bull 2015; 38:669-73. [DOI: 10.1248/bpb.b15-00060] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Yukiko K. Kaneko
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, University of Shizuoka
| | - Tomohisa Ishikawa
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, University of Shizuoka
| |
Collapse
|
24
|
Shirai Y, Saito N. Diacylglycerol kinase as a possible therapeutic target for neuronal diseases. J Biomed Sci 2014; 21:28. [PMID: 24708409 PMCID: PMC4005014 DOI: 10.1186/1423-0127-21-28] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 03/05/2014] [Indexed: 02/02/2023] Open
Abstract
Diacylglycerol kinase (DGK) is a lipid kinase converting diacylglycerol to phosphatidic acid, and regulates many enzymes including protein kinase C, phosphatidylinositol 4-phosphate 5-kinase, and mTOR. To date, ten mammalian DGK subtypes have been cloned and divided into five groups, and they show subtype-specific tissue distribution. Therefore, each DGK subtype is thought to be involved in respective cellular responses by regulating balance of the two lipid messengers, diacylglycerol and phosphatidic acid. Indeed, the recent researches using DGK knockout mice have clearly demonstrated the importance of DGK in the immune system and its pathophysiological roles in heart and insulin resistance in diabetes. Especially, most subtypes show high expression in brain with subtype specific regional distribution, suggesting that each subtype has important and unique functions in brain. Recently, neuronal functions of some DGK subtypes have accumulated. Here, we introduce DGKs with their structural motifs, summarize the enzymatic properties and neuronal functions, and discuss the possibility of DGKs as a therapeutic target of the neuronal diseases.
Collapse
Affiliation(s)
- Yasuhito Shirai
- Laboratory of Chemistry and Utilization of Animal Production Resources, Applied Chemistry in Bioscience Division, Graduate School of Agricultural Science, Kobe University, Rokkodai-cho 1-1, Nada-ku, 657-8501 Kobe, Japan.
| | | |
Collapse
|