1
|
Bruntz RC, Lindsley CW, Brown HA. Phospholipase D signaling pathways and phosphatidic acid as therapeutic targets in cancer. Pharmacol Rev 2015; 66:1033-79. [PMID: 25244928 DOI: 10.1124/pr.114.009217] [Citation(s) in RCA: 165] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Phospholipase D is a ubiquitous class of enzymes that generates phosphatidic acid as an intracellular signaling species. The phospholipase D superfamily plays a central role in a variety of functions in prokaryotes, viruses, yeast, fungi, plants, and eukaryotic species. In mammalian cells, the pathways modulating catalytic activity involve a variety of cellular signaling components, including G protein-coupled receptors, receptor tyrosine kinases, polyphosphatidylinositol lipids, Ras/Rho/ADP-ribosylation factor GTPases, and conventional isoforms of protein kinase C, among others. Recent findings have shown that phosphatidic acid generated by phospholipase D plays roles in numerous essential cellular functions, such as vesicular trafficking, exocytosis, autophagy, regulation of cellular metabolism, and tumorigenesis. Many of these cellular events are modulated by the actions of phosphatidic acid, and identification of two targets (mammalian target of rapamycin and Akt kinase) has especially highlighted a role for phospholipase D in the regulation of cellular metabolism. Phospholipase D is a regulator of intercellular signaling and metabolic pathways, particularly in cells that are under stress conditions. This review provides a comprehensive overview of the regulation of phospholipase D activity and its modulation of cellular signaling pathways and functions.
Collapse
Affiliation(s)
- Ronald C Bruntz
- Department of Pharmacology (R.C.B., C.W.L., H.A.B.) and Vanderbilt Center for Neuroscience Drug Discovery (C.W.L.), Vanderbilt University Medical Center; Department of Chemistry, Vanderbilt Institute of Chemical Biology (C.W.L., H.A.B.); Vanderbilt Specialized Chemistry for Accelerated Probe Development (C.W.L.); and Department of Biochemistry, Vanderbilt-Ingram Cancer Center (H.A.B.), Vanderbilt University, Nashville, Tennessee
| | - Craig W Lindsley
- Department of Pharmacology (R.C.B., C.W.L., H.A.B.) and Vanderbilt Center for Neuroscience Drug Discovery (C.W.L.), Vanderbilt University Medical Center; Department of Chemistry, Vanderbilt Institute of Chemical Biology (C.W.L., H.A.B.); Vanderbilt Specialized Chemistry for Accelerated Probe Development (C.W.L.); and Department of Biochemistry, Vanderbilt-Ingram Cancer Center (H.A.B.), Vanderbilt University, Nashville, Tennessee
| | - H Alex Brown
- Department of Pharmacology (R.C.B., C.W.L., H.A.B.) and Vanderbilt Center for Neuroscience Drug Discovery (C.W.L.), Vanderbilt University Medical Center; Department of Chemistry, Vanderbilt Institute of Chemical Biology (C.W.L., H.A.B.); Vanderbilt Specialized Chemistry for Accelerated Probe Development (C.W.L.); and Department of Biochemistry, Vanderbilt-Ingram Cancer Center (H.A.B.), Vanderbilt University, Nashville, Tennessee
| |
Collapse
|
2
|
Wildburger NC, Wood PL, Gumin J, Lichti CF, Emmett MR, Lang FF, Nilsson CL. ESI-MS/MS and MALDI-IMS Localization Reveal Alterations in Phosphatidic Acid, Diacylglycerol, and DHA in Glioma Stem Cell Xenografts. J Proteome Res 2015; 14:2511-9. [PMID: 25880480 DOI: 10.1021/acs.jproteome.5b00076] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Glioblastoma (GBM) is the most common adult primary brain tumor. Despite aggressive multimodal therapy, the survival of patients with GBM remains dismal. However, recent evidence has demonstrated the promise of bone marrow-derived mesenchymal stem cells (BM-hMSCs) as a therapeutic delivery vehicle for anti-glioma agents due to their ability to migrate or home to human gliomas. While several studies have demonstrated the feasibility of harnessing the homing capacity of BM-hMSCs for targeted delivery of cancer therapeutics, it is now also evident, based on clinically relevant glioma stem cell (GSC) models of GBMs, that BM-hMSCs demonstrate variable tropism toward these tumors. In this study, we compared the lipid environment of GSC xenografts that attract BM-hMSCs (N = 9) with those that do not attract (N = 9) to identify lipid modalities that are conducive to homing of BM-hMSC to GBMs. We identified lipids directly from tissue by matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) and electrospray ionization-tandem mass spectrometry (ESI-MS/MS) of lipid extracts. Several species of signaling lipids, including phosphatidic acid (PA 36:2, PA 40:5, PA 42:5, and PA 42:7) and diacylglycerol (DAG 34:0, DAG 34:1, DAG 36:1, DAG 38:4, DAG 38:6, and DAG 40:6), were lower in attracting xenografts. Molecular lipid images showed that PA (36:2), DAG (40:6), and docosahexaenoic acid (DHA) were decreased within tumor regions of attracting xenografts. Our results provide the first evidence for lipid signaling pathways and lipid-mediated tumor inflammatory responses in the homing of BM-hMSCs to GSC xenografts. Our studies provide new fundamental knowledge on the molecular correlates of the differential homing capacity of BM-hMSCs toward GSC xenografts.
Collapse
Affiliation(s)
| | - Paul L Wood
- ∥Department of Physiology and Pharmacology, Lincoln Memorial University, 6965 Cumberland Gap Parkway, Harrogate, Tennessee 37752, United States
| | | | - Cheryl F Lichti
- §UTMB Cancer Center, University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas 77555-1074, United States
| | - Mark R Emmett
- §UTMB Cancer Center, University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas 77555-1074, United States
| | | | - Carol L Nilsson
- §UTMB Cancer Center, University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas 77555-1074, United States
| |
Collapse
|
3
|
Gorden DL, Myers DS, Ivanova PT, Fahy E, Maurya MR, Gupta S, Min J, Spann NJ, McDonald JG, Kelly SL, Duan J, Sullards MC, Leiker TJ, Barkley RM, Quehenberger O, Armando AM, Milne SB, Mathews TP, Armstrong MD, Li C, Melvin WV, Clements RH, Washington MK, Mendonsa AM, Witztum JL, Guan Z, Glass CK, Murphy RC, Dennis EA, Merrill AH, Russell DW, Subramaniam S, Brown HA. Biomarkers of NAFLD progression: a lipidomics approach to an epidemic. J Lipid Res 2015; 56:722-736. [PMID: 25598080 DOI: 10.1194/jlr.p056002] [Citation(s) in RCA: 237] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The spectrum of nonalcoholic fatty liver disease (NAFLD) includes steatosis, nonalcoholic steatohepatitis (NASH), and cirrhosis. Recognition and timely diagnosis of these different stages, particularly NASH, is important for both potential reversibility and limitation of complications. Liver biopsy remains the clinical standard for definitive diagnosis. Diagnostic tools minimizing the need for invasive procedures or that add information to histologic data are important in novel management strategies for the growing epidemic of NAFLD. We describe an "omics" approach to detecting a reproducible signature of lipid metabolites, aqueous intracellular metabolites, SNPs, and mRNA transcripts in a double-blinded study of patients with different stages of NAFLD that involves profiling liver biopsies, plasma, and urine samples. Using linear discriminant analysis, a panel of 20 plasma metabolites that includes glycerophospholipids, sphingolipids, sterols, and various aqueous small molecular weight components involved in cellular metabolic pathways, can be used to differentiate between NASH and steatosis. This identification of differential biomolecular signatures has the potential to improve clinical diagnosis and facilitate therapeutic intervention of NAFLD.
Collapse
Affiliation(s)
- D Lee Gorden
- Departments of Surgery, Vanderbilt University Medical Center, Nashville, TN; Cancer Biology, Vanderbilt University Medical Center, Nashville, TN
| | - David S Myers
- Pharmacology, Vanderbilt University Medical Center, Nashville, TN
| | | | - Eoin Fahy
- Department of Bioengineering, School of Engineering, University of California, San Diego, La Jolla, CA
| | - Mano R Maurya
- Department of Bioengineering, School of Engineering, University of California, San Diego, La Jolla, CA
| | - Shakti Gupta
- Department of Bioengineering, School of Engineering, University of California, San Diego, La Jolla, CA
| | - Jun Min
- Department of Bioengineering, School of Engineering, University of California, San Diego, La Jolla, CA
| | - Nathanael J Spann
- Departments of Cellular and Molecular Medicine and Medicine, University of California, San Diego, La Jolla, CA
| | - Jeffrey G McDonald
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Samuel L Kelly
- Schools of Biology, Chemistry, and Biochemistry, and the Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA
| | - Jingjing Duan
- Schools of Biology, Chemistry, and Biochemistry, and the Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA
| | - M Cameron Sullards
- Schools of Biology, Chemistry, and Biochemistry, and the Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA
| | - Thomas J Leiker
- Department of Pharmacology, University of Colorado at Denver, Aurora, CO
| | - Robert M Barkley
- Department of Pharmacology, University of Colorado at Denver, Aurora, CO
| | - Oswald Quehenberger
- Departments of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA; Pharmacology, School of Medicine, University of California, San Diego, La Jolla, CA
| | - Aaron M Armando
- Pharmacology, School of Medicine, University of California, San Diego, La Jolla, CA
| | - Stephen B Milne
- Pharmacology, Vanderbilt University Medical Center, Nashville, TN
| | - Thomas P Mathews
- Pharmacology, Vanderbilt University Medical Center, Nashville, TN
| | | | - Chijun Li
- Department of Biochemistry, Duke University Medical Center, Durham, NC
| | - Willie V Melvin
- Departments of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Ronald H Clements
- Departments of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - M Kay Washington
- Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN
| | | | - Joseph L Witztum
- Departments of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA
| | - Ziqiang Guan
- Department of Biochemistry, Duke University Medical Center, Durham, NC
| | - Christopher K Glass
- Departments of Cellular and Molecular Medicine and Medicine, University of California, San Diego, La Jolla, CA
| | - Robert C Murphy
- Department of Pharmacology, University of Colorado at Denver, Aurora, CO
| | - Edward A Dennis
- Pharmacology, School of Medicine, University of California, San Diego, La Jolla, CA; Chemistry and Biochemistry, School of Medicine, University of California, San Diego, La Jolla, CA
| | - Alfred H Merrill
- Schools of Biology, Chemistry, and Biochemistry, and the Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA
| | - David W Russell
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Shankar Subramaniam
- Department of Bioengineering, School of Engineering, University of California, San Diego, La Jolla, CA; Chemistry and Biochemistry, School of Medicine, University of California, San Diego, La Jolla, CA.
| | - H Alex Brown
- Pharmacology, Vanderbilt University Medical Center, Nashville, TN; Biochemistry, and the Vanderbilt Institute of Chemical Biology, Vanderbilt University Medical Center, Nashville, TN.
| |
Collapse
|
5
|
Leamy AK, Egnatchik RA, Shiota M, Ivanova PT, Myers DS, Brown HA, Young JD. Enhanced synthesis of saturated phospholipids is associated with ER stress and lipotoxicity in palmitate treated hepatic cells. J Lipid Res 2014; 55:1478-88. [PMID: 24859739 DOI: 10.1194/jlr.m050237] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Indexed: 01/22/2023] Open
Abstract
High levels of saturated FAs (SFAs) are acutely toxic to a variety of cell types, including hepatocytes, and have been associated with diseases such as type 2 diabetes and nonalcoholic fatty liver disease. SFA accumulation has been previously shown to degrade endoplasmic reticulum (ER) function leading to other manifestations of the lipoapoptotic cascade. We hypothesized that dysfunctional phospholipid (PL) metabolism is an initiating factor in this ER stress response. Treatment of either primary hepatocytes or H4IIEC3 cells with the SFA palmitate resulted in dramatic dilation of the ER membrane, coinciding with other markers of organelle dysfunction. This was accompanied by increased de novo glycerolipid synthesis, significant elevation of dipalmitoyl phosphatidic acid, diacylglycerol, and total PL content in H4IIEC3 cells. Supplementation with oleate (OA) reversed these markers of palmitate (PA)-induced lipotoxicity. OA/PA cotreatment modulated the distribution of PA between lipid classes, increasing the flux toward triacylglycerols while reducing its incorporation into PLs. Similar trends were demonstrated in both primary hepatocytes and the H4IIEC3 hepatoma cell line. Overall, these findings suggest that modifying the FA composition of structural PLs can protect hepatocytes from PA-induced ER stress and associated lipotoxicity.
Collapse
Affiliation(s)
- Alexandra K Leamy
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235-1604
| | - Robert A Egnatchik
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235-1604
| | - Masakazu Shiota
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37235-1604
| | - Pavlina T Ivanova
- Department of Pharmacology, Vanderbilt University Medical Center, Vanderbilt University, Nashville, TN 37235-1604
| | - David S Myers
- Department of Pharmacology, Vanderbilt University Medical Center, Vanderbilt University, Nashville, TN 37235-1604
| | - H Alex Brown
- Department of Pharmacology, Vanderbilt University Medical Center, Vanderbilt University, Nashville, TN 37235-1604 Department of Biochemistry, Vanderbilt University, Nashville, TN 37235-1604 Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37235-1604
| | - Jamey D Young
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235-1604 Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37235-1604
| |
Collapse
|
6
|
Wakabayashi S, Freed LM, Bell JM, Rapoport SI. In vivo cerebral incorporation of radiolabeled fatty acids after acute unilateral orbital enucleation in adult hooded Long-Evans rats. J Cereb Blood Flow Metab 1994; 14:312-23. [PMID: 8113326 DOI: 10.1038/jcbfm.1994.38] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We examined effects of acute unilateral enucleation on incorporation from blood of intravenously injected unsaturated [1-14C]arachidonic acid ([14C]AA) and [1-14C]docosahexaenoic acid ([14C]DHA), and of saturated [9,10-3H]palmitic acid ([3H]PA), into visual and nonvisual brain areas of awake adult Long-Evans hooded rats. Regional cerebral metabolic rate for glucose (rCMRglc) values also were assessed with 2-deoxy-D-[1-14C]glucose ([14C]DG). One day after unilateral enucleation, an awake rat was placed in a brightly lit visual stimulation box with black and white striped walls, and a radiolabeled fatty acid was infused for 5 min or [14C]DG was injected as a bolus. [14C]DG also was injected in a group of rats kept in the dark for 4 h. Fifteen minutes after starting an infusion of a radiolabeled fatty acid, or 45 min after injecting [14C]DG, the rat was killed and the brain was prepared for quantitative autoradiography. Incorporation coefficients k* of fatty acids, or rCMRglc values, were calculated in homologous brain regions contralateral and ipsilateral to enucleation. As compared with ipsilateral regions, rCMRglc was reduced significantly (by as much as -39%) in contralateral visual areas, including the superior colliculus, lateral geniculate body, and layers I, IV, and V of the primary (striate) and secondary (association, extrastriate) visual cortices. Enucleation did not affect incorporation of [3H]PA into contralateral visual regions, but reduced incorporation of [14C]AA and of [14C]DHA by -18.5 to -2.1%. Percent reductions were correlated with percent reductions in rCMRglc in most but not all regions. No effects were noted at any of nine non-visual structures that were examined. These results indicate that enucleation acutely reduces neuronal activity in contralateral visual areas of the awake rat and that the reductions are coupled to reduced incorporation of unsaturated fatty acids into sn-2 regions of phosphatidylcholine, phosphatidylinositol, and phosphatidylethanolamine. Reduced fatty acid incorporation likely reflects reduced activity of phospholipases A2 and/or phospholipase C.
Collapse
Affiliation(s)
- S Wakabayashi
- Laboratory of Neurosciences, National Institute on Aging, National Institutes of Health, Bethesda, Maryland 20892
| | | | | | | |
Collapse
|
7
|
Robinson PJ, Noronha J, DeGeorge JJ, Freed LM, Nariai T, Rapoport SI. A quantitative method for measuring regional in vivo fatty-acid incorporation into and turnover within brain phospholipids: review and critical analysis. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 1992; 17:187-214. [PMID: 1467810 DOI: 10.1016/0165-0173(92)90016-f] [Citation(s) in RCA: 213] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
An experimental method and its associated mathematical model are described to quantitate in vivo incorporation rates into and turnovers of fatty acids (FAs) within stable brain metabolic compartments, particularly phospholipids. A radiolabeled FA is injected i.v. in a rat, and arterial plasma unacylated FA radioactivities and unlabeled concentrations are sampled until the animal is killed after 15 min, when the brain is analyzed biochemically or with quantitative autoradiography. Unbound unacylated label in blood easily crosses the blood-brain barrier; rapidly equilibrates in the unacylated FA, acyl-CoA and phosphatidate-diacylglycerol brain pools; then is incorporated into phospholipids and other stable metabolic compartments. Uptake and incorporation of labeled FAs are independent of cerebral blood flow at constant brain blood volume. Different labeled FAs enter specific sn positions of different brain phospholipids, suggesting that a combination of probes can be used to investigate metabolism of these phospholipids. Thus, [9,10-3-H]palmitate preferentially labels the sn1 position of phosphatidylcholine; [1-14C]arachidonate the sn2 positions of phosphatidylinositol and phosphatidylcholine; and [1-14C]docosahexaenoate the sn2 positions of phosphatidylethanolamine and phosphatidylcholine. The FA model provides an operational equation for rates of incorporation of FAs into brain phospholipids, taking into account intracerebral recycling and de novo synthesis of the FA, as well as entry into brain of FA from acylated blood sources. The equation is essentially independent of specific details of the proposed model, and can be used to calculate turnovers and half-lives of FAs within different phospholipid classes. For the model to be most applicable, experiments should satisfy conditions for pulse-labeling of the phospholipids, with brain sampling times short enough to minimize exchange of label between stable metabolic compartments. A 15-20 min sampling time satisfies these criteria. The FA method has been used to elucidate the dynamics of brain phospholipids metabolism in relation to brain development, brain tumor, chronically reduced auditory input, transient ischemic insult, axotomy with and without nerve regeneration, and cholinergic stimulation in animals with or without a chronic unilateral lesion of the nucleus basalis magnocellularis.
Collapse
Affiliation(s)
- P J Robinson
- Laboratory of Neurosciences, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892
| | | | | | | | | | | |
Collapse
|