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Fernandes MF, Aristizabal-Henao JJ, Marvyn PM, M'Hiri I, Wiens MA, Hoang M, Sebastian M, Nachbar R, St-Pierre P, Diaguarachchige De Silva K, Wood GA, Joseph JW, Doucette CA, Marette A, Stark KD, Duncan RE. Renal tubule-specific Atgl deletion links kidney lipid metabolism to glucagon-like peptide 1 and insulin secretion independent of renal inflammation or lipotoxicity. Mol Metab 2024; 81:101887. [PMID: 38280449 PMCID: PMC10850971 DOI: 10.1016/j.molmet.2024.101887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Accepted: 01/23/2024] [Indexed: 01/29/2024] Open
Abstract
OBJECTIVE Lipotoxic injury from renal lipid accumulation in obesity and type 2 diabetes (T2D) is implicated in associated kidney damage. However, models examining effects of renal ectopic lipid accumulation independent of obesity or T2D are lacking. We generated renal tubule-specific adipose triglyceride lipase knockout (RT-SAKO) mice to determine if this targeted triacylglycerol (TAG) over-storage affects glycemic control and kidney health. METHODS Male and female RT-SAKO mice and their control littermates were tested for changes in glycemic control at 10-12 and 16-18 weeks of age. Markers of kidney health and blood lipid and hormone concentrations were analyzed. Kidney and blood lysophosphatidic acid (LPA) levels were measured, and a role for LPA in mediating impaired glycemic control was evaluated using the LPA receptor 1/3 inhibitor Ki-16425. RESULTS All groups remained insulin sensitive, but 16- to 18-week-old male RT-SAKO mice became glucose intolerant, without developing kidney inflammation or fibrosis. Rather, these mice displayed lower circulating insulin and glucagon-like peptide 1 (GLP-1) levels. Impaired first-phase glucose-stimulated insulin secretion was detected and restored by Exendin-4. Kidney and blood LPA levels were elevated in older male but not female RT-SAKO mice, associated with increased kidney diacylglycerol kinase epsilon. Inhibition of LPA-mediated signaling restored serum GLP-1 levels, first-phase insulin secretion, and glucose tolerance. CONCLUSIONS TAG over-storage alone is insufficient to cause renal tubule lipotoxicity. This work is the first to show that endogenously derived LPA modulates GLP-1 levels in vivo, demonstrating a new mechanism of kidney-gut-pancreas crosstalk to regulate insulin secretion and glucose homeostasis.
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Affiliation(s)
- Maria F Fernandes
- Department of Kinesiology and Health Sciences, University of Waterloo, Ontario, Canada
| | | | - Phillip M Marvyn
- Department of Kinesiology and Health Sciences, University of Waterloo, Ontario, Canada
| | - Iman M'Hiri
- Department of Kinesiology and Health Sciences, University of Waterloo, Ontario, Canada
| | - Meghan A Wiens
- Department of Kinesiology and Health Sciences, University of Waterloo, Ontario, Canada
| | - Monica Hoang
- School of Pharmacy, University of Waterloo, Ontario, Canada
| | - Manuel Sebastian
- Max Rady College of Medicine, University of Manitoba, Manitoba, Canada
| | - Renato Nachbar
- Québec Heart and Lung Institute, Department of Medicine, Laval University, Québec, Canada
| | - Philippe St-Pierre
- Québec Heart and Lung Institute, Department of Medicine, Laval University, Québec, Canada
| | | | - Geoffrey A Wood
- Ontario Veterinary College, University of Guelph, Ontario, Canada
| | - Jamie W Joseph
- School of Pharmacy, University of Waterloo, Ontario, Canada
| | | | - André Marette
- Québec Heart and Lung Institute, Department of Medicine, Laval University, Québec, Canada
| | - Ken D Stark
- Department of Kinesiology and Health Sciences, University of Waterloo, Ontario, Canada
| | - Robin E Duncan
- Department of Kinesiology and Health Sciences, University of Waterloo, Ontario, Canada.
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2
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Kimura T, Kimura AK, Epand RM. Systematic crosstalk in plasmalogen and diacyl lipid biosynthesis for their differential yet concerted molecular functions in the cell. Prog Lipid Res 2023; 91:101234. [PMID: 37169310 DOI: 10.1016/j.plipres.2023.101234] [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: 03/03/2023] [Revised: 04/29/2023] [Accepted: 05/05/2023] [Indexed: 05/13/2023]
Abstract
Plasmalogen is a major phospholipid of mammalian cell membranes. Recently it is becoming evident that the sn-1 vinyl-ether linkage in plasmalogen, contrasting to the ester linkage in the counterpart diacyl glycerophospholipid, yields differential molecular characteristics for these lipids especially related to hydrocarbon-chain order, so as to concertedly regulate biological membrane processes. A role played by NMR in gaining information in this respect, ranging from molecular to tissue levels, draws particular attention. We note here that a broad range of enzymes in de novo synthesis pathway of plasmalogen commonly constitute that of diacyl glycerophospholipid. This fact forms the basis for systematic crosstalk that not only controls a quantitative balance between these lipids, but also senses a defect causing loss of lipid in either pathway for compensation by increase of the counterpart lipid. However, this inherent counterbalancing mechanism paradoxically amplifies imbalance in differential effects of these lipids in a diseased state on membrane processes. While sharing of enzymes has been recognized, it is now possible to overview the crosstalk with growing information for specific enzymes involved. The overview provides a fundamental clue to consider cell and tissue type-dependent schemes in regulating membrane processes by plasmalogen and diacyl glycerophospholipid in health and disease.
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Affiliation(s)
- Tomohiro Kimura
- Department of Chemistry & Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506, USA.
| | - Atsuko K Kimura
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - Richard M Epand
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8S 4K1, Canada
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3
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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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4
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Murakami C, Hoshino F, Sakai H, Hayashi Y, Yamashita A, Sakane F. Diacylglycerol kinase δ and sphingomyelin synthase-related protein functionally interact via their sterile α motif domains. J Biol Chem 2020; 295:2932-2947. [PMID: 31980461 DOI: 10.1074/jbc.ra119.012369] [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: 12/17/2019] [Revised: 01/23/2020] [Indexed: 12/27/2022] Open
Abstract
The δ isozyme of diacylglycerol kinase (DGKδ) plays critical roles in lipid signaling by converting diacylglycerol (DG) to phosphatidic acid (PA). We previously demonstrated that DGKδ preferably phosphorylates palmitic acid (16:0)- and/or palmitoleic acid (16:1)-containing DG molecular species, but not arachidonic acid (20:4)-containing DG species, which are recognized as DGK substrates derived from phosphatidylinositol turnover, in high glucose-stimulated myoblasts. However, little is known about the origin of these DG molecular species. DGKδ and two DG-generating enzymes, sphingomyelin synthase (SMS) 1 and SMS-related protein (SMSr), contain a sterile α motif domain (SAMD). In this study, we found that SMSr-SAMD, but not SMS1-SAMD, co-immunoprecipitates with DGKδ-SAMD. Full-length DGKδ co-precipitated with full-length SMSr more strongly than with SMS1. However, SAMD-deleted variants of SMSr and DGKδ interacted only weakly with full-length DGKδ and SMSr, respectively. These results strongly suggested that DGKδ interacts with SMSr through their respective SAMDs. To determine the functional outcomes of the relationship between DGKδ and SMSr, we used LC-MS/MS to investigate whether overexpression of DGKδ and/or SMSr in COS-7 cells alters the levels of PA species. We found that SMSr overexpression significantly enhances the production of 16:0- or 16:1-containing PA species such as 14:0/16:0-, 16:0/16:0-, 16:0/18:1-, and/or 16:1/18:1-PA in DGKδ-overexpressing COS-7 cells. Moreover, SMSr enhanced DGKδ activity via their SAMDs in vitro Taken together, these results strongly suggest that SMSr is a candidate DG-providing enzyme upstream of DGKδ and that the two enzymes represent a new pathway independent of phosphatidylinositol turnover.
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Affiliation(s)
- Chiaki Murakami
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba 263-8522, Japan
| | - Fumi Hoshino
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba 263-8522, Japan
| | - 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
| | - Yasuhiro Hayashi
- Faculty of Pharma Sciences, Teikyo University, Kaga 2-11-1, Itabashi-ku, Tokyo 173-8605, Japan
| | - Atsushi Yamashita
- Faculty of Pharma Sciences, Teikyo University, Kaga 2-11-1, Itabashi-ku, Tokyo 173-8605, Japan
| | - Fumio Sakane
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba 263-8522, Japan.
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5
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Xu Y. Targeting Lysophosphatidic Acid in Cancer: The Issues in Moving from Bench to Bedside. Cancers (Basel) 2019; 11:cancers11101523. [PMID: 31658655 PMCID: PMC6826372 DOI: 10.3390/cancers11101523] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 10/02/2019] [Accepted: 10/08/2019] [Indexed: 12/16/2022] Open
Abstract
Since the clear demonstration of lysophosphatidic acid (LPA)'s pathological roles in cancer in the mid-1990s, more than 1000 papers relating LPA to various types of cancer were published. Through these studies, LPA was established as a target for cancer. Although LPA-related inhibitors entered clinical trials for fibrosis, the concept of targeting LPA is yet to be moved to clinical cancer treatment. The major challenges that we are facing in moving LPA application from bench to bedside include the intrinsic and complicated metabolic, functional, and signaling properties of LPA, as well as technical issues, which are discussed in this review. Potential strategies and perspectives to improve the translational progress are suggested. Despite these challenges, we are optimistic that LPA blockage, particularly in combination with other agents, is on the horizon to be incorporated into clinical applications.
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Affiliation(s)
- Yan Xu
- Department of Obstetrics and Gynecology, Indiana University School of Medicine, 950 W. Walnut Street R2-E380, Indianapolis, IN 46202, USA.
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6
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Komenoi S, Suzuki Y, Asami M, Murakami C, Hoshino F, Chiba S, Takahashi D, Kado S, Sakane F. Microarray analysis of gene expression in the diacylglycerol kinase η knockout mouse brain. Biochem Biophys Rep 2019; 19:100660. [PMID: 31297456 PMCID: PMC6597918 DOI: 10.1016/j.bbrep.2019.100660] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 06/17/2019] [Accepted: 06/19/2019] [Indexed: 12/18/2022] Open
Abstract
We have revealed that diacylglycerol kinase η (DGKη)-knockout (KO) mice display bipolar disorder (BPD) remedy-sensitive mania-like behaviors. However, the molecular mechanisms causing the mania-like abnormal behaviors remain unclear. In the present study, microarray analysis was performed to determine global changes in gene expression in the DGKη-KO mouse brain. We found that the DGKη-KO brain had 43 differentially expressed genes and the following five affected biological pathways: "neuroactive ligand-receptor interaction", "transcription by RNA polymerase II", "cytosolic calcium ion concentration", "Jak-STAT signaling pathway" and "ERK1/2 cascade". Interestingly, mRNA levels of prolactin and growth hormone, which are augmented in BPD patients and model animals, were most strongly increased. Notably, all five biological pathways include at least one gene among prolactin, growth hormone, forkhead box P3, glucagon-like peptide 1 receptor and interleukin 1β, which were previously implicated in BPD. Consistent with the microarray data, phosphorylated ERK1/2 levels were decreased in the DGKη-KO brain. Microarray analysis showed that the expression levels of several glycerolipid metabolism-related genes were also changed. Liquid chromatography-mass spectrometry revealed that several polyunsaturated fatty acid (PUFA)-containing phosphatidic acid (PA) molecular species were significantly decreased as a result of DGKη deficiency, suggesting that the decrease affects PUFA metabolism. Intriguingly, the PUFA-containing lysoPA species were markedly decreased in DGKη-KO mouse blood. Taken together, our study provides not only key broad knowledge to gain novel insights into the underlying mechanisms for the mania-like behaviors but also information for developing BPD diagnostics.
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Key Words
- BPD, bipolar disorder
- Bipolar disorder
- DAVID, Database for AnnotationVisualization and Integrated Discovery
- DG, diacylglycerol
- DGK, diacylglycerol kinase
- Diacylglycerol kinase
- ERK, extracellular signal-regulated kinase
- Fpr2, N-formyl peptide receptor 2
- GO:BP, Gene Ontology: Biological Process
- GWAS, genome-wide association study
- Gh, growth hormone
- Glp1r, glucagon-like peptide 1 receptor
- Growth hormone
- Il1b, interleukin 1β
- KEGG, Kyoto Encyclopedia of Genes and Genomes
- KO, knockout
- LC-MS, liquid chromatography-mass spectrometry
- LPA, lysophosphatidic acid
- Lysophosphatidic acid
- MEK, mitogen-activated protein kinase/ERK kinase
- PA, phosphatidic acid
- PI, phosphatidylinositol
- PUFA, polyunsaturated fatty acid
- Phosphatidic acid
- Prl, prolactin
- Prolactin
- SERT, serotonin transporter
- WT, wild type
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Affiliation(s)
- Suguru Komenoi
- Department of Chemistry, Graduate School of Science, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
| | - Yuji Suzuki
- Department of Chemistry, Graduate School of Science, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
| | - Maho Asami
- Department of Chemistry, Graduate School of Science, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
| | - Chiaki Murakami
- Department of Chemistry, Graduate School of Science, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
| | - Fumi Hoshino
- Department of Chemistry, Graduate School of Science, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
| | - Sohei Chiba
- Department of Chemistry, Graduate School of Science, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
| | - Daisuke Takahashi
- Department of Chemistry, Graduate School of Science, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
| | - Sayaka Kado
- Center for Analytical Instrumentation, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
| | - Fumio Sakane
- Department of Chemistry, Graduate School of Science, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
- Corresponding author. Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan.
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7
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Saito T, Takahashi D, Sakane F. Expression, Purification, and Characterization of Human Diacylglycerol Kinase ζ. ACS OMEGA 2019; 4:5540-5546. [PMID: 31893253 PMCID: PMC6935893 DOI: 10.1021/acsomega.9b00079] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 03/08/2019] [Indexed: 05/14/2023]
Abstract
Diacylglycerol kinase ζ (DGKζ) phosphorylates diacylglycerol (DG) to generate phosphatidic acid. The dysfunction of DGKζ has been linked to several diseases, such as cardiac hypertrophy, ischemia, and seizures. Moreover, much attention has been paid to DGKζ, together with DGKα, as a potential target for cancer immunotherapy. However, DGKζ has never been purified and, thus, neither its enzymatic properties nor its structure has yet been reported, hindering our understanding of the catalytic mechanism of DGKζ and the development of a reasonable structure-based drug design. In the present study, we generated a full-length DGKζ using a baculovirus-insect cell expression system for enzymological and structural studies. Full-length DGKζ remained soluble and was purified to near homogeneity as a monomer with yields suitable for protein crystallization (0.63 mg/1 L culture). Enzymatic characterization showed that the purified DGKζ is in a fully functional state. The K m values for adenosine triphosphate (ATP) and DG were 0.05 mM and 1.5 mol %, respectively, and the EC50 for the activator phosphatidylserine was 8.6 mol %, indicating that its affinity for ATP is moderately higher than those of DGKα and DGKε, and its affinities for DG and phosphatidylserine are comparable to those of DGKα/DGKε. We further confirmed that the purified enzyme could be concentrated without any significant aggregation. Circular dichroism revealed that DGKζ is comprised of 25% α-helices and 18% β-strands. This is the first successful purification and characterization of the enzymatic and conformational properties of DGKζ. The purification of DGKζ allows detailed analyses of this important enzyme and will advance our understanding of DGKζ-related diseases and therapies.
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Affiliation(s)
- Takumi Saito
- Department
of Chemistry, Graduate School of Science, Chiba University, 1-33
Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
| | - Daisuke Takahashi
- Department
of Pharmaceutical Health Care and Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Fumio Sakane
- Department
of Chemistry, Graduate School of Science, Chiba University, 1-33
Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
- E-mail: . Tel/Fax: +81-43-290-3695
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8
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Bozelli JC, Jennings W, Black S, Hou YH, Lameire D, Chatha P, Kimura T, Berno B, Khondker A, Rheinstädter MC, Epand RM. Membrane curvature allosterically regulates the phosphatidylinositol cycle, controlling its rate and acyl-chain composition of its lipid intermediates. J Biol Chem 2018; 293:17780-17791. [PMID: 30237168 DOI: 10.1074/jbc.ra118.005293] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 09/04/2018] [Indexed: 01/17/2023] Open
Abstract
Signaling events at membranes are often mediated by membrane lipid composition or membrane physical properties. These membrane properties could act either by favoring the membrane binding of downstream effectors or by modulating their activity. Several proteins can sense/generate membrane physical curvature (i.e. shape). However, the modulation of the activity of enzymes by a membrane's shape has not yet been reported. Here, using a cell-free assay with purified diacylglycerol kinase ϵ (DGKϵ) and liposomes, we studied the activity and acyl-chain specificity of an enzyme of the phosphatidylinositol (PI) cycle, DGKϵ. By systematically varying the model membrane lipid composition and physical properties, we found that DGKϵ has low activity and lacks acyl-chain specificity in locally flat membranes, regardless of the lipid composition. On the other hand, these enzyme properties were greatly enhanced in membrane structures with a negative Gaussian curvature. We also found that this is not a consequence of preferential binding of the enzyme to those structures, but rather is due to a curvature-mediated allosteric regulation of DGKϵ activity and acyl-chain specificity. Moreover, in a fine-tuned interplay between the enzyme and the membrane, DGKϵ favored the formation of structures with greater Gaussian curvature. DGKϵ does not bear a regulatory domain, and these findings reveal the importance of membrane curvature in regulating DGKϵ activity and acyl-chain specificity. Hence, this study highlights that a hierarchic coupling of membrane physical property and lipid composition synergistically regulates membrane signaling events. We propose that this regulatory mechanism of membrane-associated enzyme activity is likely more common than is currently appreciated.
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Affiliation(s)
- José Carlos Bozelli
- From the Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, Ontario L8S 4K1
| | - William Jennings
- From the Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, Ontario L8S 4K1
| | - Stephanie Black
- From the Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, Ontario L8S 4K1
| | - Yu Heng Hou
- From the Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, Ontario L8S 4K1
| | - Darius Lameire
- From the Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, Ontario L8S 4K1
| | - Preet Chatha
- From the Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, Ontario L8S 4K1
| | - Tomohiro Kimura
- From the Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, Ontario L8S 4K1
| | | | - Adree Khondker
- Physics and Astronomy; Origins Institute, McMaster University, Hamilton, Ontario L8S 4L8, Canada
| | - Maikel C Rheinstädter
- Physics and Astronomy; Origins Institute, McMaster University, Hamilton, Ontario L8S 4L8, Canada
| | - Richard M Epand
- From the Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, Ontario L8S 4K1; Departments of Chemistry.
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Tigyi GJ, Yue J, Norman DD, Szabo E, Balogh A, Balazs L, Zhao G, Lee SC. Regulation of tumor cell - Microenvironment interaction by the autotaxin-lysophosphatidic acid receptor axis. Adv Biol Regul 2018; 71:183-193. [PMID: 30243984 DOI: 10.1016/j.jbior.2018.09.008] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 09/12/2018] [Accepted: 09/13/2018] [Indexed: 12/12/2022]
Abstract
The lipid mediator lysophosphatidic acid (LPA) in biological fluids is primarily produced by cleavage of lysophospholipids by the lysophospholipase D enzyme Autotaxin (ATX). LPA has been identified and abundantly detected in the culture medium of various cancer cell types, tumor effusates, and ascites fluid of cancer patients. Our current understanding of the physiological role of LPA established its role in fundamental biological responses that include cell proliferation, metabolism, neuronal differentiation, angiogenesis, cell migration, hematopoiesis, inflammation, immunity, wound healing, regulation of cell excitability, and the promotion of cell survival by protecting against apoptotic death. These essential biological responses elicited by LPA are seemingly hijacked by cancer cells in many ways; transcriptional upregulation of ATX leading to increased LPA levels, enhanced expression of multiple LPA GPCR subtypes, and the downregulation of its metabolic breakdown. Recent studies have shown that overexpression of ATX and LPA GPCR can lead to malignant transformation, enhanced proliferation of cancer stem cells, increased invasion and metastasis, reprogramming of the tumor microenvironment and the metastatic niche, and development of resistance to chemo-, immuno-, and radiation-therapy of cancer. The fundamental role of LPA in cancer progression and the therapeutic inhibition of the ATX-LPA axis, although highly appealing, remains unexploited as drug development to these targets has not reached into the clinic yet. The purpose of this brief review is to highlight some unique signaling mechanisms engaged by the ATX-LPA axis and emphasize the therapeutic potential that lies in blocking the molecular targets of the LPA system.
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Affiliation(s)
- Gabor J Tigyi
- Department of Physiology, University of Tennessee Health Science Center Memphis, Memphis, TN, 38163, USA; Institute of Clinical Experimental Research, Semmelweis University, POB 2, H-1428, Budapest, Hungary.
| | - Junming Yue
- Department of Pathology, University of Tennessee Health Science Center Memphis, Memphis, TN, 38163, USA
| | - Derek D Norman
- Department of Physiology, University of Tennessee Health Science Center Memphis, Memphis, TN, 38163, USA
| | - Erzsebet Szabo
- Department of Physiology, University of Tennessee Health Science Center Memphis, Memphis, TN, 38163, USA
| | - Andrea Balogh
- Department of Physiology, University of Tennessee Health Science Center Memphis, Memphis, TN, 38163, USA; Institute of Clinical Experimental Research, Semmelweis University, POB 2, H-1428, Budapest, Hungary
| | - Louisa Balazs
- Department of Pathology, University of Tennessee Health Science Center Memphis, Memphis, TN, 38163, USA
| | - Guannan Zhao
- Department of Pathology, University of Tennessee Health Science Center Memphis, Memphis, TN, 38163, USA
| | - Sue Chin Lee
- Department of Physiology, University of Tennessee Health Science Center Memphis, Memphis, TN, 38163, USA
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10
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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.
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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
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Gupta RS, Epand RM. Phylogenetic analysis of the diacylglycerol kinase family of proteins and identification of multiple highly-specific conserved inserts and deletions within the catalytic domain that are distinctive characteristics of different classes of DGK homologs. PLoS One 2017; 12:e0182758. [PMID: 28829789 PMCID: PMC5567653 DOI: 10.1371/journal.pone.0182758] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 07/24/2017] [Indexed: 01/01/2023] Open
Abstract
Diacylglycerol kinase (DGK) family of proteins, which phosphorylates diacylglycerol into phosphatidic acid, play important role in controlling diverse cellular processes in eukaryotic organisms. Most vertebrate species contain 10 different DGK isozymes, which are grouped into 5 different classes based on the presence or absence of specific functional domains. However, the relationships among different DGK isozymes or how they have evolved from a common ancestor is unclear. The catalytic domain constitutes the single largest sequence element within the DGK proteins that is commonly and uniquely shared by all family members, but there is limited understanding of the overall function of this domain. In this work, we have used the catalytic domain sequences to construct a phylogenetic tree for the DGK family members from representatives of the main vertebrate classes and have also examined the distributions of various DGK isozymes in eukaryotic phyla. In a tree based on catalytic domain sequences, the DGK homologs belonging to different classes formed strongly supported clusters which were separated by long branches, and the different isozymes within each class also generally formed monophyletic groupings. Further, our analysis of the sequence alignments of catalytic domains has identified >10 novel sequence signatures consisting of conserved signature indels (inserts or deletions, CSIs) that are distinctive characteristics of either particular classes of DGK isozymes, or are commonly shared by members of two or more classes of DGK isozymes. The conserved indels in protein sequences are known to play important functional roles in the proteins/organisms where they are found. Thus, our identification of multiple highly specific CSIs that are distinguishing characteristics of different classes of DGK homologs points to the existence of important differences in the catalytic domain function among the DGK isozymes. The identified CSIs in conjunction with the results of blast searches on species distribution of DGK isozymes also provide useful insights into the evolutionary relationships among the DGK family of proteins.
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Affiliation(s)
- Radhey S. Gupta
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
- * E-mail:
| | - Richard M. Epand
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
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Epand RM, So V, Jennings W, Khadka B, Gupta RS, Lemaire M. Diacylglycerol Kinase-ε: Properties and Biological Roles. Front Cell Dev Biol 2016; 4:112. [PMID: 27803897 PMCID: PMC5067486 DOI: 10.3389/fcell.2016.00112] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 09/27/2016] [Indexed: 12/20/2022] Open
Abstract
In mammals there are at least 10 isoforms of diacylglycerol kinases (DGK). All catalyze the phosphorylation of diacylglycerol (DAG) to phosphatidic acid (PA). Among DGK isoforms, DGKε has several unique features. It is the only DGK isoform with specificity for a particular species of DAG, i.e., 1-stearoyl-2-arachidonoyl glycerol. The smallest of all known DGK isoforms, DGKε, is also the only DGK devoid of a regulatory domain. DGKε is the only DGK isoform that has a hydrophobic segment that is predicted to form a transmembrane helix. As the only membrane-bound, constitutively active DGK isoform with exquisite specificity for particular molecular species of DAG, the functional overlap between DGKε and other DGKs is predicted to be minimal. DGKε exhibits specificity for DAG containing the same acyl chains as those found in the lipid intermediates of the phosphatidylinositol-cycle. It has also been shown that DGKε affects the acyl chain composition of phosphatidylinositol in whole cells. It is thus likely that DGKε is responsible for catalyzing one step in the phosphatidylinositol-cycle. Steps of this cycle take place in both the plasma membrane and the endoplasmic reticulum membrane. DGKε is likely present in both of these membranes. DGKε is the only DGK isoform that is associated with a human disease. Indeed, recessive loss-of-function mutations in DGKε cause atypical hemolytic-uremic syndrome (aHUS). This condition is characterized by thrombosis in the small vessels of the kidney. It causes acute renal insufficiency in infancy and most patients develop end-stage renal failure before adulthood. Disease pathophysiology is poorly understood and there is no therapy. There are also data suggesting that DGKε may play a role in epilepsy and Huntington disease. Thus, DGKε has many unique molecular and biochemical properties when compared to all other DGK isoforms. DGKε homologs also contain a number of conserved sequence features that are distinctive characteristics of either the rodents or specific groups of primate homologs. How cells, tissues and organisms harness DGKε's catalytic prowess remains unclear. The discovery of DGKε's role in causing aHUS will hopefully boost efforts to unravel the mechanisms by which DGKε dysfunction causes disease.
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Affiliation(s)
- Richard M Epand
- Department of Biochemistry and Biomedical Sciences, McMaster University Health Sciences Centre Hamilton, ON, Canada
| | - Vincent So
- Department of Biochemistry and Biomedical Sciences, McMaster University Health Sciences CentreHamilton, ON, Canada; Nephrology Division and Cell Biology Program, Hospital for Sick ChildrenToronto, ON, Canada
| | - William Jennings
- Department of Biochemistry and Biomedical Sciences, McMaster University Health Sciences Centre Hamilton, ON, Canada
| | - Bijendra Khadka
- Department of Biochemistry and Biomedical Sciences, McMaster University Health Sciences Centre Hamilton, ON, Canada
| | - Radhey S Gupta
- Department of Biochemistry and Biomedical Sciences, McMaster University Health Sciences Centre Hamilton, ON, Canada
| | - Mathieu Lemaire
- Nephrology Division and Cell Biology Program, Hospital for Sick ChildrenToronto, ON, Canada; Department of Biochemistry, University of TorontoToronto, ON, Canada; Institute of Medicine, University of TorontoToronto, ON, Canada
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13
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Epand RM, So V, Jennings W, Khadka B, Gupta RS, Lemaire M. Diacylglycerol Kinase-ε: Properties and Biological Roles. Front Cell Dev Biol 2016. [PMID: 27803897 DOI: 10.3389/fcell.2016.00112)] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
In mammals there are at least 10 isoforms of diacylglycerol kinases (DGK). All catalyze the phosphorylation of diacylglycerol (DAG) to phosphatidic acid (PA). Among DGK isoforms, DGKε has several unique features. It is the only DGK isoform with specificity for a particular species of DAG, i.e., 1-stearoyl-2-arachidonoyl glycerol. The smallest of all known DGK isoforms, DGKε, is also the only DGK devoid of a regulatory domain. DGKε is the only DGK isoform that has a hydrophobic segment that is predicted to form a transmembrane helix. As the only membrane-bound, constitutively active DGK isoform with exquisite specificity for particular molecular species of DAG, the functional overlap between DGKε and other DGKs is predicted to be minimal. DGKε exhibits specificity for DAG containing the same acyl chains as those found in the lipid intermediates of the phosphatidylinositol-cycle. It has also been shown that DGKε affects the acyl chain composition of phosphatidylinositol in whole cells. It is thus likely that DGKε is responsible for catalyzing one step in the phosphatidylinositol-cycle. Steps of this cycle take place in both the plasma membrane and the endoplasmic reticulum membrane. DGKε is likely present in both of these membranes. DGKε is the only DGK isoform that is associated with a human disease. Indeed, recessive loss-of-function mutations in DGKε cause atypical hemolytic-uremic syndrome (aHUS). This condition is characterized by thrombosis in the small vessels of the kidney. It causes acute renal insufficiency in infancy and most patients develop end-stage renal failure before adulthood. Disease pathophysiology is poorly understood and there is no therapy. There are also data suggesting that DGKε may play a role in epilepsy and Huntington disease. Thus, DGKε has many unique molecular and biochemical properties when compared to all other DGK isoforms. DGKε homologs also contain a number of conserved sequence features that are distinctive characteristics of either the rodents or specific groups of primate homologs. How cells, tissues and organisms harness DGKε's catalytic prowess remains unclear. The discovery of DGKε's role in causing aHUS will hopefully boost efforts to unravel the mechanisms by which DGKε dysfunction causes disease.
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Affiliation(s)
- Richard M Epand
- Department of Biochemistry and Biomedical Sciences, McMaster University Health Sciences Centre Hamilton, ON, Canada
| | - Vincent So
- Department of Biochemistry and Biomedical Sciences, McMaster University Health Sciences CentreHamilton, ON, Canada; Nephrology Division and Cell Biology Program, Hospital for Sick ChildrenToronto, ON, Canada
| | - William Jennings
- Department of Biochemistry and Biomedical Sciences, McMaster University Health Sciences Centre Hamilton, ON, Canada
| | - Bijendra Khadka
- Department of Biochemistry and Biomedical Sciences, McMaster University Health Sciences Centre Hamilton, ON, Canada
| | - Radhey S Gupta
- Department of Biochemistry and Biomedical Sciences, McMaster University Health Sciences Centre Hamilton, ON, Canada
| | - Mathieu Lemaire
- Nephrology Division and Cell Biology Program, Hospital for Sick ChildrenToronto, ON, Canada; Department of Biochemistry, University of TorontoToronto, ON, Canada; Institute of Medicine, University of TorontoToronto, ON, Canada
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