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Parinandi NL, Liaugminas A, Oliver PJ, Varadharaj S, Yenigalla A, Elliott AC, Arutla S, Campbell SJ, Kotha SR, Sherwani SI, Kutala VK, McDaniel JC, Maddipati KR, Kuppusamy P, Hund TJ. Classic Phytochemical Antioxidant and Lipoxygenase Inhibitor, Nordihydroguaiaretic Acid, Activates Phospholipase D through Oxidant Signaling and Tyrosine Phosphorylation Leading to Cytotoxicity in Lung Vascular Endothelial Cells. Cell Biochem Biophys 2023:10.1007/s12013-023-01128-1. [PMID: 36820994 DOI: 10.1007/s12013-023-01128-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/02/2023] [Indexed: 02/24/2023]
Abstract
Nordihydroguaiaretic acid (NDGA), a dicatechol and phytochemical polyphenolic antioxidant and an established inhibitor of human arachidonic acid (AA) 5-lipoxygenase (LOX) and 15-LOX, is widely used to ascertain the role of LOXs in vascular endothelial cell (EC) function. As the modulatory effect of NDGA on phospholipase D (PLD), an important lipid signaling enzyme in ECs, thus far has not been reported, here we have investigated the modulation of PLD activity and its regulation by NDGA in the bovine pulmonary artery ECs (BPAECs). NDGA induced the activation of PLD (phosphatidic acid formation) in cells in a dose- and time-dependent fashion that was significantly attenuated by iron chelator and antioxidants. NDGA induced the formation of reactive oxygen species (ROS) in cells in a dose- and time-dependent manner as evidenced from fluorescence microscopy and fluorimetry of ROS and electron paramagnetic resonance spectroscopy of oxygen radicals. Also, NDGA caused a dose-dependent loss of intracellular glutathione (GSH) in BPAECs. Protein tyrosine kinase (PTyK)-specific inhibitors significantly attenuated NDGA-induced PLD activation in BPAECs. NDGA also induced a dose- and time-dependent phosphorylation of tyrosine in proteins in cells. NDGA caused in situ translocation and relocalization of both PLD1 and PLD2 isoforms, in a time-dependent fashion. Cyclooxygenase (COX) inhibitors were ineffective in attenuating NDGA-induced PLD activation in BPAECs, thus ruling out the activation of COXs by NDGA. NDGA inhibited the AA-LOX activity and leukotriene C4 (LTC4) formation in cells. On the other hand, the 5-LOX-specific inhibitors, 5, 8, 11, 14-eicosatetraynoic acid and kaempferol, were ineffective in activating PLD in BPAECs. Antioxidants and PTyK-specific inhibitors effectively attenuated NDGA cytotoxicity in BPAECs. The PLD-specific inhibitor, 5-fluoro-2-indolyl deschlorohalopemide (FIPI), significantly attenuated and protected against the NDGA-induced PLD activation and cytotoxicity in BPAECs. For the first time, these results demonstrated that NDGA, the classic phytochemical polyphenolic antioxidant and LOX inhibitor, activated PLD causing cytotoxicity in ECs through upstream oxidant signaling and protein tyrosine phosphorylation.
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Affiliation(s)
- Narasimham L Parinandi
- Lipid Signaling, Lipidomics, and Vasculotoxicity Laboratory, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine and Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA.
| | - Alex Liaugminas
- Lipid Signaling, Lipidomics, and Vasculotoxicity Laboratory, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine and Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Patrick J Oliver
- Lipid Signaling, Lipidomics, and Vasculotoxicity Laboratory, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine and Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Saradhadevi Varadharaj
- Lipid Signaling, Lipidomics, and Vasculotoxicity Laboratory, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine and Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Anita Yenigalla
- Lipid Signaling, Lipidomics, and Vasculotoxicity Laboratory, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine and Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Austin C Elliott
- Lipid Signaling, Lipidomics, and Vasculotoxicity Laboratory, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine and Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Sukruthi Arutla
- Lipid Signaling, Lipidomics, and Vasculotoxicity Laboratory, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine and Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Steven J Campbell
- Lipid Signaling, Lipidomics, and Vasculotoxicity Laboratory, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine and Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Sainath R Kotha
- Lipid Signaling, Lipidomics, and Vasculotoxicity Laboratory, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine and Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Shariq I Sherwani
- Lipid Signaling, Lipidomics, and Vasculotoxicity Laboratory, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine and Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Vijay K Kutala
- Lipid Signaling, Lipidomics, and Vasculotoxicity Laboratory, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine and Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Jodi C McDaniel
- Lipid Signaling, Lipidomics, and Vasculotoxicity Laboratory, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine and Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Krishna Rao Maddipati
- Department of Pathology and Lipidomics Core Facility, Wayne State University, Detroit, MI, 48202, USA
| | - Periannan Kuppusamy
- Department of Medicine, Geisel School of Medicine, Dartmouth College, Lebanon, NH, 03756, USA
| | - Thomas J Hund
- Lipid Signaling, Lipidomics, and Vasculotoxicity Laboratory, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine and Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
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Kang MJ, Jin N, Park SY, Han JS. Phospholipase D1 promotes astrocytic differentiation through the FAK/AURKA/STAT3 signaling pathway in hippocampal neural stem/progenitor cells. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119361. [PMID: 36162649 DOI: 10.1016/j.bbamcr.2022.119361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 08/29/2022] [Accepted: 09/12/2022] [Indexed: 06/16/2023]
Abstract
Phospholipase D1 (PLD1) plays a crucial role in cell differentiation of different cell types. However, the involvement of PLD1 in astrocytic differentiation remains uncertain. In the present study, we investigate the possible role of PLD1 and its product phosphatidic acid (PA) in astrocytic differentiation of hippocampal neural stem/progenitor cells (NSPCs) from hippocampi of embryonic day 16.5 rat embryos. We showed that overexpression of PLD1 increased the expression level of glial fibrillary acidic protein (GFAP), an astrocyte marker, and the number of GFAP-positive cells. Knockdown of PLD1 by transfection with Pld1 shRNA inhibited astrocytic differentiation. Moreover, PLD1 deletion (Pld1-/-) suppressed the level of GFAP in the mouse hippocampus. These results indicate that PLD1 plays a crucial role in regulating astrocytic differentiation in hippocampal NSPCs. Interestingly, PA itself was sufficient to promote astrocytic differentiation. PA-induced GFAP expression was decreased by inhibition of signal transducer and activation of transcription 3 (STAT3) using siRNA. Furthermore, PA-induced STAT3 activation and astrocytic differentiation were regulated by the focal adhesion kinase (FAK)/aurora kinase A (AURKA) pathway. Taken together, our findings suggest that PLD1 is an important modulator of astrocytic differentiation in hippocampal NSPCs via the FAK/AURKA/STAT3 signaling pathway.
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Affiliation(s)
- Min-Jeong Kang
- Department of Biomedical Sciences, Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul 04763, Republic of Korea
| | - Nuri Jin
- Department of Biomedical Sciences, Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul 04763, Republic of Korea
| | - Shin-Young Park
- Biomedical Research Institute and Department of Biochemistry and Molecular Biology, College of Medicine, Hanyang University, Seoul 04763, Republic of Korea.
| | - Joong-Soo Han
- Department of Biomedical Sciences, Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul 04763, Republic of Korea; Biomedical Research Institute and Department of Biochemistry and Molecular Biology, College of Medicine, Hanyang University, Seoul 04763, Republic of Korea.
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Llorente-Ovejero A, Martínez-Gardeazabal J, Moreno-Rodríguez M, Lombardero L, González de San Román E, Manuel I, Giralt MT, Rodríguez-Puertas R. Specific Phospholipid Modulation by Muscarinic Signaling in a Rat Lesion Model of Alzheimer's Disease. ACS Chem Neurosci 2021; 12:2167-2181. [PMID: 34037379 PMCID: PMC9162383 DOI: 10.1021/acschemneuro.1c00169] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
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Alzheimer’s disease (AD) represents
the most common cause
of dementia worldwide and has been consistently associated with the
loss of basal forebrain cholinergic neurons (BFCNs) leading to impaired
cholinergic neurotransmission, aberrant synaptic function, and altered
structural lipid metabolism. In this sense, membrane phospholipids
(PLs) can be used for de novo synthesis of choline (Ch) for the further
obtaining of acetylcholine (ACh) when its availability is compromised.
Specific lipid species involved in the metabolism of Ch have been
identified as possible biomarkers of phenoconversion to AD. Using
a rat model of BFCN lesion, we have evaluated the lipid composition
and muscarinic signaling in brain areas related to cognitive processes.
The loss of BFCN resulted in alterations of varied lipid species related
to Ch metabolism at nucleus basalis magnocellularis (NMB) and cortical
projection areas. The activity of muscarinic receptors (mAChR) was
decreased in the NMB and increased in the hippocampus according to
the subcellular distribution of M1/M2 mAChR
which could explain the learning and memory impairment reported in
this AD rat model. These results suggest that the modulation of specific
lipid metabolic routes could represent an alternative therapeutic
strategy to potentiate cholinergic neurotransmission and preserve
cell membrane integrity in AD.
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Affiliation(s)
- Alberto Llorente-Ovejero
- Department of Pharmacology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), B° Sarriena s/n, 48940 Leioa, Spain
| | - Jonatan Martínez-Gardeazabal
- Department of Pharmacology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), B° Sarriena s/n, 48940 Leioa, Spain
| | - Marta Moreno-Rodríguez
- Department of Pharmacology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), B° Sarriena s/n, 48940 Leioa, Spain
| | - Laura Lombardero
- Department of Pharmacology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), B° Sarriena s/n, 48940 Leioa, Spain
| | - Estíbaliz González de San Román
- Department of Pharmacology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), B° Sarriena s/n, 48940 Leioa, Spain
| | - Iván Manuel
- Department of Pharmacology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), B° Sarriena s/n, 48940 Leioa, Spain
- Neurodegenerative Diseases, BioCruces Bizkaia Health Research Institute, 48903 Barakaldo, Spain
| | - María Teresa Giralt
- Department of Pharmacology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), B° Sarriena s/n, 48940 Leioa, Spain
| | - Rafael Rodríguez-Puertas
- Department of Pharmacology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), B° Sarriena s/n, 48940 Leioa, Spain
- Neurodegenerative Diseases, BioCruces Bizkaia Health Research Institute, 48903 Barakaldo, Spain
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Pyfrom SC, Quinn CC, Dorando HK, Luo H, Payton JE. BCALM (AC099524.1) Is a Human B Lymphocyte-Specific Long Noncoding RNA That Modulates B Cell Receptor-Mediated Calcium Signaling. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2020; 205:595-607. [PMID: 32571842 PMCID: PMC7372127 DOI: 10.4049/jimmunol.2000088] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 05/27/2020] [Indexed: 12/12/2022]
Abstract
Of the thousands of long noncoding RNAs (lncRNA) identified in lymphocytes, very few have defined functions. In this study, we report the discovery and functional elucidation of a human B cell-specific lncRNA with high levels of expression in three types of B cell cancer and normal B cells. The AC099524.1 gene is upstream of the gene encoding the B cell-specific phospholipase C γ 2 (PLCG2), a B cell-specific enzyme that stimulates intracellular Ca2+ signaling in response to BCR activation. AC099524.1 (B cell-associated lncRNA modulator of BCR-mediated Ca+ signaling [BCALM]) transcripts are localized in the cytoplasm and, as expected, CRISPR/Cas9 knockout of AC099524.1 did not affect PLCG2 mRNA or protein expression. lncRNA interactome, RNA immunoprecipitation, and coimmunoprecipitation studies identified BCALM-interacting proteins in B cells, including phospholipase D 1 (PLD1), and kinase adaptor proteins AKAP9 (AKAP450) and AKAP13 (AKAP-Lbc). These two AKAP proteins form signaling complexes containing protein kinases A and C, which phosphorylate and activate PLD1 to produce phosphatidic acid (PA). BCR stimulation of BCALM-deficient B cells resulted in decreased PLD1 phosphorylation and increased intracellular Ca+ flux relative to wild-type cells. These results suggest that BCALM promotes negative feedback that downmodulates BCR-mediated Ca+ signaling by promoting phosphorylation of PLD1 by AKAP-associated kinases, enhancing production of PA. PA activates SHP-1, which negatively regulates BCR signaling. We propose the name BCALM for B-Cell Associated LncRNA Modulator of BCR-mediated Ca+ signaling. Our findings suggest a new, to our knowledge, paradigm for lncRNA-mediated modulation of lymphocyte activation and signaling, with implications for B cell immune response and BCR-dependent cancers.
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Affiliation(s)
- Sarah C Pyfrom
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Chaz C Quinn
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Hannah K Dorando
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Hong Luo
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Jacqueline E Payton
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
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5
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Polyunsaturated fatty acid-containing phosphatidic acids selectively interact with L-lactate dehydrogenase A and induce its secondary structural change and inactivation. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158768. [PMID: 32717303 DOI: 10.1016/j.bbalip.2020.158768] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 06/17/2020] [Accepted: 07/19/2020] [Indexed: 12/18/2022]
Abstract
Phosphatidic acid (PA) consists of various molecular species that have different fatty acyl chains at the sn-1 and sn-2 positions; and consequently, mammalian cells contain at least 50 structurally distinct PA molecular species. However, the different roles of each PA species are poorly understood. In the present study, we attempted to identify dipalmitoyl (16:0/16:0)-PA-binding proteins from mouse skeletal muscle using liposome precipitation and tandem mass spectrometry analysis. We identified L-lactate dehydrogenase (LDH) A, which catalyzes conversion of pyruvate to lactate and is a key checkpoint of anaerobic glycolysis critical for tumor growth, as a 16:0/16:0-PA-binding protein. LDHA did not substantially associate with other phospholipids, such as phosphatidylcholine, phosphatidylserine, phosphatidylglycerol, phosphatidylinositol, phosphoinositides and cardiolipin at physiological pH (7.4), indicating that LDHA specifically bound to PA. Interestingly, 18:0/18:0-, 18:0/20:4- and 18:0/22:6-PA also interacted with LDHA, and their binding activities were stronger than 16:0/16:0-PA at pH 7.4. Moreover, circular dichroism spectrometry showed that 18:0/20:4- and 18:0/22:6-PA, but not 16:0/16:0- or 18:0/18:0-PA, significantly reduced the α-helical structure of LDHA. Furthermore, 18:0/20:4- and 18:0/22:6-PA attenuated LDH activity. Taken together, we demonstrated for the first time that LDHA is a PA-binding protein and is a unique PA-binding protein that is structurally and functionally controlled by associating with 18:0/20:4- and 18:0/22:6-PA.
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Abstract
Cirrhosis is a multisystemic disease wherein inflammatory responses originating from advanced liver disease and its sequelae affect distant compartments. Patients with cirrhosis are susceptible to bacterial infections, which may precipitate acute decompensation and acute-on-chronic liver failure, both of which are associated with high short-term mortality. Innate immune cells are an essential first line of defence against pathogens. Activation of liver macrophages (Kupffer cells) and resident mastocytes generate proinflammatory and vaso-permeating mediators that induce accumulation of neutrophils, lymphocytes, eosinophils and monocytes in the liver, and promote tissue damage. During cirrhosis progression, damage- and pathogen-associated molecular patterns activate immune cells and promote development of systemic inflammatory responses which may involve different tissues and compartments. The antibacterial function of circulating neutrophils and monocytes is gradually and severely impaired as cirrhosis worsens, contributing to disease progression. The mechanisms underlying impaired antimicrobial responses are complex and incompletely understood. This review focuses on the continuous and distinct perturbations arising in innate immune cells during cirrhosis, including their impact on disease progression, as well as reviewing potential therapeutic targets.
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Huta Y, Nitzan Y, Breitbart H. Ezrin protects bovine spermatozoa from spontaneous acrosome reaction. Theriogenology 2020; 151:119-127. [PMID: 32334120 DOI: 10.1016/j.theriogenology.2020.04.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 04/12/2020] [Accepted: 04/13/2020] [Indexed: 11/18/2022]
Abstract
To interact and penetrate the egg, the spermatozoon must undergo a maturation step called the acrosome reaction (AR) in close proximity to the egg. This process can take place only after a series of biochemical changes to the sperm occur in the female reproductive tract, collectively called capacitation. Spermatozoa can undergo spontaneous-acrosome reaction (sAR) before reaching the vicinity of the egg, preventing successful fertilization. Several mechanisms were shown to protect spermatozoa from undergoing sAR. Here we describe the involvement of the actin cross-linker, Ezrin in the mechanism that protects spermatozoa from sAR. Inhibition of Ezrin stimulates sAR and inhibits actin polymerization. Ezrin is highly phosphorylated/activated during the first hour of the capacitation process, and its phosphorylation rate is subsequently decreased. Ezrin phosphorylation depends on protein kinase A (PKA) and calmodulin kinase II (CaMKII) activities, and to some extent on phosphatidyl-inositol-4-kinase (PI4K) activity. Inhibition of these three kinases stimulates sAR, in which the effect of PI4K inhibition, but not PKA or CaMKII inhibition, can be reversed by increasing p-Ezrin using a phosphatase inhibitor. All together, we showed that three kinases mediate Ezrin activation during spermatozoa capacitation, leading to actin polymerization in a mechanism that prevents sAR.
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Affiliation(s)
- Y Huta
- The Mina &Everard Faculty of Life Sciences,Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Y Nitzan
- Department of Clinical Laboratory Science, Zefat Academic College, Zefat, 1320611, Israel
| | - H Breitbart
- The Mina &Everard Faculty of Life Sciences,Bar-Ilan University, Ramat-Gan, 5290002, Israel.
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8
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Petersen EN, Pavel MA, Wang H, Hansen SB. Disruption of palmitate-mediated localization; a shared pathway of force and anesthetic activation of TREK-1 channels. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2020; 1862:183091. [PMID: 31672538 PMCID: PMC6907892 DOI: 10.1016/j.bbamem.2019.183091] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 09/15/2019] [Accepted: 09/17/2019] [Indexed: 12/22/2022]
Abstract
TWIK related K+ channel (TREK-1) is a mechano- and anesthetic sensitive channel that when activated attenuates pain and causes anesthesia. Recently the enzyme phospholipase D2 (PLD2) was shown to bind to the channel and generate a local high concentration of phosphatidic acid (PA), an anionic signaling lipid that gates TREK-1. In a biological membrane, the cell harnesses lipid heterogeneity (lipid compartments) to control gating of TREK-1 using palmitate-mediated localization of PLD2. Here we discuss the ability of mechanical force and anesthetics to disrupt palmitate-mediated localization of PLD2 giving rise to TREK-1's mechano- and anesthetic-sensitive properties. The likely consequences of this indirect lipid-based mechanism of activation are discussed in terms of a putative model for excitatory and inhibitory mechano-effectors and anesthetic sensitive ion channels in a biological context. Lastly, we discuss the ability of locally generated PA to reach mM concentrations near TREK-1 and the biophysics of localized signaling. Palmitate-mediated localization of PLD2 emerges as a central control mechanism of TREK-1 responding to mechanical force and anesthetic action. This article is part of a Special Issue entitled: Molecular biophysics of membranes and membrane proteins.
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Affiliation(s)
- E Nicholas Petersen
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL 33458, USA; Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Mahmud Arif Pavel
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL 33458, USA; Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Hao Wang
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL 33458, USA; Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Scott B Hansen
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL 33458, USA; Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA.
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9
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McDermott MI, Wang Y, Wakelam MJO, Bankaitis VA. Mammalian phospholipase D: Function, and therapeutics. Prog Lipid Res 2019; 78:101018. [PMID: 31830503 DOI: 10.1016/j.plipres.2019.101018] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 10/08/2019] [Accepted: 10/14/2019] [Indexed: 01/23/2023]
Abstract
Despite being discovered over 60 years ago, the precise role of phospholipase D (PLD) is still being elucidated. PLD enzymes catalyze the hydrolysis of the phosphodiester bond of glycerophospholipids producing phosphatidic acid and the free headgroup. PLD family members are found in organisms ranging from viruses, and bacteria to plants, and mammals. They display a range of substrate specificities, are regulated by a diverse range of molecules, and have been implicated in a broad range of cellular processes including receptor signaling, cytoskeletal regulation and membrane trafficking. Recent technological advances including: the development of PLD knockout mice, isoform-specific antibodies, and specific inhibitors are finally permitting a thorough analysis of the in vivo role of mammalian PLDs. These studies are facilitating increased recognition of PLD's role in disease states including cancers and Alzheimer's disease, offering potential as a target for therapeutic intervention.
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Affiliation(s)
- M I McDermott
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843-1114, United States of America.
| | - Y Wang
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843-1114, United States of America; Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843-2128, United States of America
| | - M J O Wakelam
- Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | - V A Bankaitis
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843-1114, United States of America; Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843-2128, United States of America; Department of Chemistry, Texas A&M University, College Station, Texas 77840, United States of America
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10
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Shim JK, Caron MA, Weatherly LM, Gerchman LB, Sangroula S, Hattab S, Baez AY, Briana TJ, Gosse JA. Antimicrobial agent triclosan suppresses mast cell signaling via phospholipase D inhibition. J Appl Toxicol 2019; 39:1672-1690. [PMID: 31429102 DOI: 10.1002/jat.3884] [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: 12/21/2018] [Revised: 07/02/2019] [Accepted: 07/03/2019] [Indexed: 12/27/2022]
Abstract
Humans are exposed to the antimicrobial agent triclosan (TCS) through use of TCS-containing products. Exposed tissues contain mast cells, which are involved in numerous biological functions and diseases by secreting various chemical mediators through a process termed degranulation. We previously demonstrated that TCS inhibits both Ca2+ influx into antigen-stimulated mast cells and subsequent degranulation. To determine the mechanism linking the TCS cytosolic Ca2+ depression to inhibited degranulation, we investigated the effects of TCS on crucial signaling enzymes activated downstream of the Ca2+ rise: protein kinase C (PKC; activated by Ca2+ and reactive oxygen species [ROS]) and phospholipase D (PLD). We found that TCS strongly inhibits PLD activity within 15 minutes post-antigen, a key mechanism of TCS mast cell inhibition. In addition, experiments using fluorescent constructs and confocal microscopy indicate that TCS delays antigen-induced translocations of PKCβII, PKCδ and PKC substrate myristoylated alanine-rich C-kinase. Surprisingly, TCS does not inhibit PKC activity or overall ability to translocate, and TCS actually increases PKC activity by 45 minutes post-antigen; these results are explained by the timing of both TCS inhibition of cytosolic Ca2+ (~15+ minutes post-antigen) and TCS stimulation of ROS (~45 minutes post-antigen). These findings demonstrate that it is incorrect to assume that all Ca2+ -dependent processes will be synchronously inhibited when cytosolic Ca2+ is inhibited by a toxicant or drug. The results offer molecular predictions of the effects of TCS on other mammalian cell types, which share these crucial signal transduction elements and provide biochemical information that may underlie recent epidemiological findings implicating TCS in human health problems.
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Affiliation(s)
- Juyoung K Shim
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, Maine
| | - Molly A Caron
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, Maine
| | - Lisa M Weatherly
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, Maine.,Graduate School of Biomedical Science and Engineering, University of Maine, Orono, Maine
| | - Logan B Gerchman
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, Maine
| | - Suraj Sangroula
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, Maine
| | - Siham Hattab
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, Maine
| | - Alan Y Baez
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, Maine
| | - Talya J Briana
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, Maine
| | - Julie A Gosse
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, Maine.,Graduate School of Biomedical Science and Engineering, University of Maine, Orono, Maine
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Tsirulnikov E, Huta Y, Breitbart H. PKA and PI3K activities during capacitation protect sperm from undergoing spontaneous acrosome reaction. Theriogenology 2019; 128:54-61. [DOI: 10.1016/j.theriogenology.2019.01.036] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Revised: 12/24/2018] [Accepted: 01/31/2019] [Indexed: 12/20/2022]
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12
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Role of phospholipase D in migration and invasion induced by linoleic acid in breast cancer cells. Mol Cell Biochem 2019; 457:119-132. [PMID: 30877512 DOI: 10.1007/s11010-019-03517-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 03/08/2019] [Indexed: 02/07/2023]
Abstract
Linoleic acid (LA) is an essential and omega-6 polyunsaturated fatty acid that mediates a variety of biological processes, including migration and invasion in breast cancer cells. Phospholipase D (PLD) catalyses the hydrolysis of phosphatidylcholine to produce phosphatidic acid and choline. Increases of expression and activity of PLD are reported in several human cancers, including gastric, colorectal, renal, stomach, lung and breast. In this article, we demonstrate that LA induces an increase of PLD activity in MDA-MB-231 breast cancer cells. Particularly, PLD1 and/or PLD2 mediate migration and invasion induced by LA. Moreover, LA induces increases in number and size of spheroids via PLD activity. FFAR1 also mediates migration and invasion, whereas PLD activation induced by LA requires the activities of FFAR1, FFAR4 and EGFR in MDA-MB-231 cells. In summary, PLD plays a pivotal role in migration and invasion induced by LA in MDA-MB-231 breast cancer cells.
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Brailoiu E, Chakraborty S, Brailoiu GC, Zhao P, Barr JL, Ilies MA, Unterwald EM, Abood ME, Taylor CW. Choline Is an Intracellular Messenger Linking Extracellular Stimuli to IP 3-Evoked Ca 2+ Signals through Sigma-1 Receptors. Cell Rep 2019; 26:330-337.e4. [PMID: 30625315 PMCID: PMC6326163 DOI: 10.1016/j.celrep.2018.12.051] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 10/11/2018] [Accepted: 12/11/2018] [Indexed: 11/18/2022] Open
Abstract
Sigma-1 receptors (Sig-1Rs) are integral ER membrane proteins. They bind diverse ligands, including psychoactive drugs, and regulate many signaling proteins, including the inositol 1,4,5-trisphosphate receptors (IP3Rs) that release Ca2+ from the ER. The endogenous ligands of Sig-1Rs are unknown. Phospholipase D (PLD) cleaves phosphatidylcholine to choline and phosphatidic acid (PA), with PA assumed to mediate all downstream signaling. We show that choline is also an intracellular messenger. Choline binds to Sig-1Rs, it mimics other Sig-1R agonists by potentiating Ca2+ signals evoked by IP3Rs, and it is deactivated by metabolism. Receptors, by stimulating PLC and PLD, deliver two signals to IP3Rs: IP3 activates IP3Rs, and choline potentiates their activity through Sig-1Rs. Choline is also produced at synapses by degradation of acetylcholine. Choline uptake by transporters activates Sig-1Rs and potentiates Ca2+ signals. We conclude that choline is an endogenous agonist of Sig-1Rs linking extracellular stimuli, and perhaps synaptic activity, to Ca2+ signals.
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Affiliation(s)
- Eugen Brailoiu
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA.
| | | | - G Cristina Brailoiu
- Department of Pharmaceutical Sciences, Jefferson College of Pharmacy, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Pingwei Zhao
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Jeffrey L Barr
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Marc A Ilies
- Department of Pharmaceutical Sciences, Temple University School of Pharmacy, Philadelphia, PA 19140, USA
| | - Ellen M Unterwald
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Mary E Abood
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Colin W Taylor
- Department of Pharmacology, Tennis Court Road, Cambridge CB2 1PD, UK.
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El Amri M, Fitzgerald U, Schlosser G. MARCKS and MARCKS-like proteins in development and regeneration. J Biomed Sci 2018; 25:43. [PMID: 29788979 PMCID: PMC5964646 DOI: 10.1186/s12929-018-0445-1] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 05/07/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The Myristoylated Alanine-Rich C-kinase Substrate (MARCKS) and MARCKS-like protein 1 (MARCKSL1) have a wide range of functions, ranging from roles in embryonic development to adult brain plasticity and the inflammatory response. Recently, both proteins have also been identified as important players in regeneration. Upon phosphorylation by protein kinase C (PKC) or calcium-dependent calmodulin-binding, MARCKS and MARCKSL1 translocate from the membrane into the cytosol, modulating cytoskeletal actin dynamics and vesicular trafficking and activating various signal transduction pathways. As a consequence, the two proteins are involved in the regulation of cell migration, secretion, proliferation and differentiation in many different tissues. MAIN BODY Throughout vertebrate development, MARCKS and MARCKSL1 are widely expressed in tissues derived from all germ layers, with particularly strong expression in the nervous system. They have been implicated in the regulation of gastrulation, myogenesis, brain development, and other developmental processes. Mice carrying loss of function mutations in either Marcks or Marcksl1 genes die shortly after birth due to multiple deficiencies including detrimental neural tube closure defects. In adult vertebrates, MARCKS and MARCKL1 continue to be important for multiple regenerative processes including peripheral nerve, appendage, and tail regeneration, making them promising targets for regenerative medicine. CONCLUSION This review briefly summarizes the molecular interactions and cellular functions of MARCKS and MARCKSL1 proteins and outlines their vital roles in development and regeneration.
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Affiliation(s)
- Mohamed El Amri
- Centre for Research in Medical Devices (CÚRAM), National University of Ireland, Galway, Biomedical Sciences Building, Newcastle Road, Galway, Ireland
| | - Una Fitzgerald
- Galway Neuroscience Centre, School of Natural Sciences, Biomedical Sciences Building, National University of Ireland, Newcastle Road, Galway, Ireland
| | - Gerhard Schlosser
- Centre for Research in Medical Devices (CÚRAM), National University of Ireland, Galway, Biomedical Sciences Building, Newcastle Road, Galway, Ireland. .,School of Natural Sciences and Regenerative Medicine Institute (REMEDI), National University of Ireland, Galway, Biomedical Sciences Building, Newcastle Road, Galway, Ireland.
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15
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Abstract
Phospholipase D (PLD) enzymes are one source of receptor-generated phosphatidic acid (PtdOH),which may subsequently be metabolized to diacylglycerol (DAG) and lysophosphatidic acid. There are other pathways that lead to PtdOH generation, but differences in pathways and in the acyl composition of the products seem to provide some specificity. Both direct and indirect inhibitors of PLD activity have been identified despite a long-held suspicion that this pathway was undruggable. The identification of raloxifene and halopemide as direct inhibitors was followed by the systematic development of isoenzyme-preferring compounds that have been used to further differentiate the functions of PLD1 and PLD2. PLD2 in host cells has been associated with viral entry processes and innate immune response pathways such that inhibition blocks efficient infection. This PLD2 pathway has been linked to autophagy via AKT kinases. As a potential target in antiretroviral therapy, PLD1 works through the CAD enzyme (which contains carbamoyl aspartate synthase, aspartate transcarbamylase and dihydro-orotase domains) to modulate pyrimidine biosynthesis. PLD activity and expression have been shown to be upregulated in several types of human cancers, in which PLD enzymes function downstream of a variety of known oncogenes. Inhibition of PtdOH production has a marked effect on tumorigenesis and malignant invasion. PLD1, PLD2 and PLD3 have each been suggested to have a role in Alzheimer disease and other neurodegenerative conditions, but a mechanism has not yet emerged to explain the roles of these proteins in central nervous system pathophysiology.
Lipid second messengers such as phosphatidic acid (PtdOH) have a role in a wide range of pathological processes, and phospholipase D (PLD) enzymes are one of the major sources of signal-activated PtdOH generation. In this Review, Brown, Thomas and Lindsley discuss the development of PLD inhibitors, with a focus on isoform-specific inhibitors, and their potential applications in the treatment of cancer, neurodegeneration and infection. Lipid second messengers have essential roles in cellular function and contribute to the molecular mechanisms that underlie inflammation, malignant transformation, invasiveness, neurodegenerative disorders, and infectious and other pathophysiological processes. The phospholipase D (PLD) isoenzymes PLD1 and PLD2 are one of the major sources of signal-activated phosphatidic acid (PtdOH) generation downstream of a variety of cell-surface receptors, including G protein-coupled receptors (GPCRs), receptor tyrosine kinases (RTKs) and integrins. Recent advances in the development of isoenzyme-selective PLD inhibitors and in molecular genetics have suggested that PLD isoenzymes in mammalian cells and pathogenic organisms may be valuable targets for the treatment of several human diseases. Isoenzyme-selective inhibitors have revealed complex inter-relationships between PtdOH biosynthetic pathways and the role of PtdOH in pathophysiology. PLD enzymes were once thought to be undruggable owing to the ubiquitous nature of PtdOH in cell signalling and concerns that inhibitors would be too toxic for use in humans. However, recent promising discoveries suggest that small-molecule isoenzyme-selective inhibitors may provide novel compounds for a unique approach to the treatment of cancers, neurodegenerative disorders and other afflictions of the central nervous system, and potentially serve as broad-spectrum antiviral and antimicrobial therapeutics.
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Lee SY, Lee YY, Choi JS, Yoon MS, Han JS. Phosphatidic acid induces decidualization by stimulating Akt-PP2A binding in human endometrial stromal cells. FEBS J 2016; 283:4163-4175. [PMID: 27696687 DOI: 10.1111/febs.13914] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 09/06/2016] [Accepted: 09/29/2016] [Indexed: 12/19/2022]
Abstract
Decidualization of human endometrial stromal cells (hESCs) is crucial for successful uterine implantation and maintaining pregnancy. We previously reported that phospholipase D1 (PLD1) is required for cAMP-induced decidualization of hESCs. However, the mechanism by which phosphatidic acid (PA), the product of PLD1 action, might regulate decidualization is not known. We confirmed that PA induced decidualization of hESCs by observing morphological changes and measuring increased levels of decidualization markers such as IGFBP1 and prolactin transcripts (P < 0.05). Treatment with PA reduced phosphorylation of Akt and consequently that of FoxO1, which led to the increased IGFBP1 and prolactin mRNA levels (P < 0.05). Conversely, PLD1 knockdown rescued Akt phosphorylation. Binding of PP2A and Akt increased in response to cAMP or PA, suggesting that their binding is directly responsible for the inactivation of Akt during decidualization. Consistent with this observation, treatment with okadaic acid, a PP2A inhibitor, also inhibited cAMP-induced decidualization by blocking Akt dephosphorylation.
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Affiliation(s)
- So Young Lee
- Department of Biomedical Sciences, Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, Korea
| | - Yun Young Lee
- Department of Biomedical Sciences, Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, Korea
| | - Joong Sub Choi
- Department of Obstetrics and Gynecology, College of Medicine, Hanyang University, Seoul, Korea
| | - Mee-Sup Yoon
- Department of Molecular Medicine, School of Medicine, Gachon University, Incheon, Korea
| | - Joong-Soo Han
- Department of Biomedical Sciences, Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, Korea.,Biomedical Research Institute and Department of Biochemistry and Molecular Biology, College of Medicine, Hanyang University, Seoul, Korea
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17
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Raben DM, Barber CN. Phosphatidic acid and neurotransmission. Adv Biol Regul 2016; 63:15-21. [PMID: 27671966 DOI: 10.1016/j.jbior.2016.09.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 09/15/2016] [Accepted: 09/19/2016] [Indexed: 12/31/2022]
Abstract
Lipids play a vital role in the health and functioning of neurons and interest in the physiological role of neuronal lipids is certainly increasing. One neuronal function in which neuronal lipids appears to play key roles in neurotransmission. Our understanding of the role of lipids in the synaptic vesicle cycle and neurotransmitter release is becoming increasingly more important. Much of the initial research in this area has highlighted the major roles played by the phosphoinositides (PtdIns), diacylglycerol (DAG), and phosphatidic acid (PtdOH). Of these, PtdOH has not received as much attention as the other lipids although its role and metabolism appears to be extremely important. This lipid has been shown to play a role in modulating both exocytosis and endocytosis although its precise role in either process is not well defined. The currently evidence suggest this lipid likely participates in key processes by altering membrane architecture necessary for membrane fusion, mediating the penetration of membrane proteins, serving as a precursor for other important SV cycling lipids, or activating essential enzymes. In this review, we address the sources of PtdOH, the enzymes involved in its production, the regulation of these enzymes, and its potential roles in neurotransmission in the central nervous system.
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Affiliation(s)
- Daniel M Raben
- The Department of Biological Chemistry, The Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA.
| | - Casey N Barber
- The Department of Biological Chemistry, The Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA
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18
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Shabtay O, Breitbart H. CaMKII prevents spontaneous acrosomal exocytosis in sperm through induction of actin polymerization. Dev Biol 2016; 415:64-74. [PMID: 27178669 DOI: 10.1016/j.ydbio.2016.05.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 05/08/2016] [Accepted: 05/09/2016] [Indexed: 02/01/2023]
Abstract
In order to interact with the egg and undergo acrosomal exocytosis or the acrosome reaction (AR), mammalian spermatozoa must undergo a series of biochemical changes in the female reproductive tract, collectively called capacitation. We showed that F-actin is formed during sperm capacitation and fast depolymerization occurs prior to the AR. We hypothesized that F-actin protects the sperm from undergoing spontaneous-AR (sAR) which decreases fertilization rate. We show that activation of the actin-severing protein gelsolin induces a significant increase in sAR. Moreover, inhibition of CaMKII or PLD during sperm capacitation, caused an increase in sAR and inhibition of F-actin formation. Spermine, which leads to PLD activation, was able to reverse the effects of CaMKII inhibition on sAR-increase and F-actin-decrease. Furthermore, the increase in sAR and the decrease in F-actin caused by the inactivation of the PLD-pathway, were reversed by activation of CaMKII using H2O2 or by inhibiting protein phosphatase 1 which enhance the phosphorylation and oxidation states of CaMKII. These results indicate that two distinct pathways lead to F-actin formation in the sperm capacitation process which prevents the occurrence of sAR.
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Affiliation(s)
- Ortal Shabtay
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Haim Breitbart
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
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19
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Koo JB, Han JS. Cigarette smoke extract-induced interleukin-6 expression is regulated by phospholipase D1 in human bronchial epithelial cells. J Toxicol Sci 2016; 41:77-89. [DOI: 10.2131/jts.41.77] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Jun Bon Koo
- Biomedical Research Institute and Department of Biochemistry & Molecular Biology, College of Medicine, Hanyang University, Korea
| | - Joong-Soo Han
- Biomedical Research Institute and Department of Biochemistry & Molecular Biology, College of Medicine, Hanyang University, Korea
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20
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Choi HJ, Park SY, Cho JH, Park JW, Sohn JH, Kim YJ, Oh JW, Han JS. The TLR4-associated phospholipase D1 activation is crucial for Der f 2-induced IL-13 production. Allergy 2015; 70:1569-79. [PMID: 26335962 DOI: 10.1111/all.12764] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/31/2015] [Indexed: 01/11/2023]
Abstract
BACKGROUND House dust mites (HDMs) are the most important source of indoor aeroallergens that contribute to the rising incidence of allergic diseases such as allergic asthma. The major HDM, Der f 2, induces inflammatory cytokine expression. Little is known about the signaling pathway involved. OBJECTIVE We wanted to define the Der f 2 signaling pathway from its receptor to the transcription factor responsible for IL-13 expression and production. METHODS Human bronchial epithelial cells were stimulated with Der f 2. The release and gene expression of IL-13 were measured by means of ELISA and RT-PCR, respectively. In the airway inflammation mouse model, airway responses were assessed using ELISA, histology, BAL fluid, and methacholine responsiveness. RESULTS Here, we show that Der f 2 binds to TLR4 and induces IL-13 expression and production. In the airway inflammation mouse model, Der f 2-induced IL-13 production significantly decreased with treatment of TAK-242, a novel TLR4 inhibitor. Activation of TLR4 by Der f 2 requires the recruitment and activation of Syk, which leads to phosphorylation of PLCγ and membrane translocation of PKCα. p38 MAPK is then activated by PKCα and stimulates PLD1 activity by phosphorylating the Thr147 residue of PLD1. PLD1 activation enhanced binding of ROCK1 to ATF-2 and leads to increased expression of IL-13. CONCLUSION Our data extend the knowledge for a variety of possible roles of PLD1 in allergic disorders including asthma pathogenesis and suggest possible candidacy of PLD1 as a molecular target for novel therapeutic approaches.
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Affiliation(s)
- H.-J. Choi
- Biomedical Research Institute and Department of Biochemistry and Molecular Biology; College of Medicine; Hanyang University; Seoul Korea
| | - S.-Y. Park
- Biomedical Research Institute and Department of Biochemistry and Molecular Biology; College of Medicine; Hanyang University; Seoul Korea
| | - J. H. Cho
- Biomedical Research Institute and Department of Biochemistry and Molecular Biology; College of Medicine; Hanyang University; Seoul Korea
| | - J.-W. Park
- Department of Internal Medicine and Institute of Allergy; College of Medicine; Yonsei University; Seoul Korea
| | - J.-H. Sohn
- Department of Internal Medicine and Institute of Allergy; College of Medicine; Yonsei University; Seoul Korea
| | - Y.-J. Kim
- Department of Internal Medicine and Institute of Allergy; College of Medicine; Yonsei University; Seoul Korea
| | - J.-W. Oh
- Department of Pediatrics; College of Medicine; Hanyang University; Seoul Korea
| | - J.-S. Han
- Biomedical Research Institute and Department of Biochemistry and Molecular Biology; College of Medicine; Hanyang University; Seoul Korea
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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: 161] [Impact Index Per Article: 17.9] [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.
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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
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Shad BJ, Smeuninx B, Atherton PJ, Breen L. The mechanistic and ergogenic effects of phosphatidic acid in skeletal muscle. Appl Physiol Nutr Metab 2015; 40:1233-41. [PMID: 26566242 DOI: 10.1139/apnm-2015-0350] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Skeletal muscle mass plays a vital role in locomotion, whole-body metabolic health, and is a positive predictor of longevity. It is well established the mammalian target of rapamycin (mTOR) is a central regulator of skeletal muscle protein turnover. The pursuit to find novel nutrient compounds or functional food sources that possess the ability to activate mTOR and promote skeletal muscle protein accretion has been on going. Over the last decade, a key role has been proposed for the phospholipid phosphatidic acid (PA) in mTOR activation. Mechanical load-induced (i.e., resistance exercise) intramuscular PA can directly bind to and activate mTOR. In addition, PA provided exogenously in cell culture heightens mTOR activity, albeit indirectly. Thus, endogenously generated PA and exogenous provision of PA appear to act through distinct mechanisms that converge on mTOR and, potentially, may amplify muscle protein synthesis. In support of this notion, limited evidence from humans suggests that resistance exercise training combined with oral supplemental PA enhances strength gains and muscle hypertrophy. However, the precise mechanisms underpinning the augmented muscle remodelling response with supplemental PA remain elusive. In this review, we will critically examine available evidence from cell cultures and animal and human experimental models to provide an overview of the mechanisms through which endogenous and exogenous PA may act to promote muscle anabolism, and discuss the potential for PA as a therapeutic tool to maintain or restore skeletal muscle mass in the context of ageing and disease.
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Affiliation(s)
- Brandon James Shad
- a School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Benoit Smeuninx
- a School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Philip James Atherton
- b MRC-ARUK Centre for Excellence in Musculoskeletal Ageing Research, Birmingham, UK.,c Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital, Nottingham, DE22 3DT, UK
| | - Leigh Breen
- b MRC-ARUK Centre for Excellence in Musculoskeletal Ageing Research, Birmingham, UK.,d School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, UK
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Omanwar S, Fahim M. Mercury Exposure and Endothelial Dysfunction: An Interplay Between Nitric Oxide and Oxidative Stress. Int J Toxicol 2015; 34:300-7. [PMID: 26060268 DOI: 10.1177/1091581815589766] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Vascular endothelium plays a vital role in the organization and function of the blood vessel and maintains homeostasis of the circulatory system and normal arterial function. Functional disruption of the endothelium is recognized as the beginning event that triggers the development of consequent cardiovascular disease (CVD) including atherosclerosis and coronary heart disease. There is a growing data associating mercury exposure with endothelial dysfunction and higher risk of CVD. This review explores and evaluates the impact of mercury exposure on CVD and endothelial function, highlighting the interplay of nitric oxide and oxidative stress.
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Affiliation(s)
- Swati Omanwar
- School of Sciences, Indira Gandhi National Open University, New Delhi, India
| | - M Fahim
- Hamdard Institute of Medical Science and Research, Hamdard University, New Delhi, India
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24
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Hansen SB. Lipid agonism: The PIP2 paradigm of ligand-gated ion channels. BIOCHIMICA ET BIOPHYSICA ACTA 2015; 1851:620-8. [PMID: 25633344 PMCID: PMC4540326 DOI: 10.1016/j.bbalip.2015.01.011] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 01/05/2015] [Accepted: 01/17/2015] [Indexed: 01/08/2023]
Abstract
The past decade, membrane signaling lipids emerged as major regulators of ion channel function. However, the molecular nature of lipid binding to ion channels remained poorly described due to a lack of structural information and assays to quantify and measure lipid binding in a membrane. How does a lipid-ligand bind to a membrane protein in the plasma membrane, and what does it mean for a lipid to activate or regulate an ion channel? How does lipid binding compare to activation by soluble neurotransmitter? And how does the cell control lipid agonism? This review focuses on lipids and their interactions with membrane proteins, in particular, ion channels. I discuss the intersection of membrane lipid biology and ion channel biophysics. A picture emerges of membrane lipids as bona fide agonists of ligand-gated ion channels. These freely diffusing signals reside in the plasma membrane, bind to the transmembrane domain of protein, and cause a conformational change that allosterically gates an ion channel. The system employs a catalog of diverse signaling lipids ultimately controlled by lipid enzymes and raft localization. I draw upon pharmacology, recent protein structure, and electrophysiological data to understand lipid regulation and define inward rectifying potassium channels (Kir) as a new class of PIP2 lipid-gated ion channels.
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Affiliation(s)
- Scott B Hansen
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter FL 33458, USA; Department of Neuroscience, The Scripps Research Institute, Jupiter FL 33458, USA.
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Phospholipase D activates HIF-1-VEGF pathway via phosphatidic acid. Exp Mol Med 2014; 46:e126. [PMID: 25523098 PMCID: PMC4274397 DOI: 10.1038/emm.2014.86] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 10/02/2014] [Accepted: 10/06/2014] [Indexed: 01/30/2023] Open
Abstract
Growth factor-stimulated phospholipase D (PLD) catalyzes the hydrolysis of phosphatidylcholine (PC), generating phosphatidic acid (PA) which may act as a second messenger during cell proliferation and survival. Therefore, PLD is believed to play an important role in tumorigenesis. In this study, a potential mechanism for PLD-mediated tumorigenesis was explored. Ectopic expression of PLD1 or PLD2 in human glioma U87 cells increased the expression of hypoxia-inducible factor-1α (HIF-1α) protein. PLD-induced HIF-1 activation led to the secretion of vascular endothelial growth factor (VEGF), a HIF-1 target gene involved in tumorigenesis. PLD induction of HIF-1α was significantly attenuated by 1-butanol which blocks PA production by PLD, and PA per se was able to elevate HIF-1α protein level. Inhibition of mTOR, a PA-responsive kinase, reduced the levels of HIF-1α and VEGF in PLD-overexpressed cells. Epidermal growth factor activated PLD and increased the levels of HIF-1α and VEGF in U87 cells. A specific PLD inhibitor abolished expression of HIF-1α and secretion of VEGF. PLD may utilize HIF-1-VEGF pathway for PLD-mediated tumor cell proliferation and survival.
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Olanzapine inhibits proliferation, migration and anchorage-independent growth in human glioblastoma cell lines and enhances temozolomide's antiproliferative effect. J Neurooncol 2014; 122:21-33. [PMID: 25524815 DOI: 10.1007/s11060-014-1688-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Accepted: 12/14/2014] [Indexed: 10/24/2022]
Abstract
The poor prognosis of patients with glioblastoma fuels the search for more effective therapeutic compounds. We previously hypothesised that the neuroleptic olanzapine may enhance antineoplastic effects of temozolomide the standard chemotherapeutic agent used in this disease. This study tested this hypothesis. The anti-proliferative effect of olanzapine was examined by MTT assays and cell count analysis. Soft-agar assays were performed to examine colony-forming ability. In addition, the inhibitory effect of olanzapine on the migratory capacity of U87MG and A172 cells was analyzed by Transwell(®) assays. Moreover, staining for annexin V/propidium iodide or carboxyfluorescein succinimidyl ester was performed prior to flow cytometric analysis in order to better understand the subjacent cellular mechanism. Our initial hypothesis that olanzapine may enhance temozolomide's anti-tumor activity could be confirmed in U87MG and A172 glioblastoma cell lines. Moreover, treatment with olanzapine alone resulted in a marked anti-proliferative effect on U87MG, A172 and two glioma stem-like cells with IC50 values ranging from 25 to 79.9 µM. In U87MG cells, anchorage-independent growth was dose-dependently inhibited. In A172 cells, migration was also shown to be inhibited in a dose-dependent manner. In addition, olanzapine was shown to exert a cell line-dependent pleomorphism with respect to the induction of apoptosis, necrosis and/or cytostasis. Our data show that the neuroleptic olanzapine enhances the anti-tumor activity of temozolomide against glioblastoma cell lines. Moreover, this is the first study to show that olanzapine provides on its own anti-cancer activity in glioblastoma and thus may have potential for repurposing.
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Stritt S, Thielmann I, Dütting S, Stegner D, Nieswandt B. Phospholipase D is a central regulator of collagen I-induced cytoskeletal rearrangement and podosome formation in megakaryocytes. J Thromb Haemost 2014; 12:1364-71. [PMID: 24909796 DOI: 10.1111/jth.12623] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 05/26/2014] [Indexed: 11/28/2022]
Abstract
BACKGROUND Blood platelets are small anucleated cell fragments generated from bone marrow megakaryocytes (MKs) by a cytoskeleton-driven process. Thereby, mature MKs form long cytoplasmic protrusions (pro-platelets), which extend into the sinusoids within the bone marrow and finally release platelets. Podosomes are F-actin rich matrix contacts that have been suggested to play an important role in cell migration, but also in pro-platelet formation by MKs. Phospholipase D (PLD) has been proposed to contribute to the regulation of actin dynamics through the local generation of phosphatidic acid but its role in platelet formation is unknown. OBJECTIVE We sought to investigate the significance of PLD in MK podosome formation and thrombocytopoiesis. METHODS Podosome formation, spreading and ultra-structure of PLD single- and double-deficient MKs were analyzed using confocal and transmission electron microscopy. RESULTS Phospholipase D-deficient MKs displayed a highly altered ultra-structure in vivo and abnormal actin rearrangement, with almost abolished formation of podosomes upon spreading on collagen I in vitro. However, MK endomitosis and platelet production were not altered by PLD deficiency. CONCLUSION Together, our findings point to a specific function of PLD in actin dynamics as well as podosome formation and size determination in MKs on a collagen I matrix. The normal platelet number in PLD-deficient mice, however, suggests the existence of compensatory mechanisms in vivo that overcome the defective podosome formation observed in vitro.
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Affiliation(s)
- S Stritt
- Department of Experimental Biomedicine, University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, Germany
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Krzystanek M, Krzystanek E, Trzeciak HI, Małecki A, Krupka-Matuszczyk I, Janas-Kozik M, Rybakowski JK. Effects of olanzapine and paroxetine on phospholipase D activity in the rat brain. Pharmacol Rep 2014; 65:724-9. [PMID: 23950596 DOI: 10.1016/s1734-1140(13)71051-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 02/02/2013] [Indexed: 01/28/2023]
Abstract
BACKGROUND Phospholipase D (PLD) plays a key role in a second messenger system producing phosphatidic acid, mediating, among others, serotonin 5-HT2 receptor activity. The aim of the study was to evaluate a possible effect of atypical antipsychotic drug, olanzapine (OLZ), and selective serotonin reuptake inhibitor (SSRI) antidepressant, paroxetine (PX), on oleate-activated PLD activity in plasma membranes isolated from rat brain cortex. METHODS PLD activity was determined using a fluorometric assay. Ritanserin was used to determine the 5-HT receptor mode of action. RESULTS A single dose of 10 mmol/kg OLZ produced no change in rat brain cortex PLD activity, 20 mmol/kg OLZ caused a nonsignificant decrease, and long-term (21 days) administration of OLZ resulted in a 41.9% decrease in PLD activity. Single doses of PX significantly decreased PLD activity: 10 mmol/kg - by 28.6%; 20 mmol/kg - by 31.5%, and long-term (21 days) administration of PX - by 39.5%. CONCLUSION The study indicates that the 5-HT2 receptor-mediated inhibition of oleate-activated PLD may be a common part of the mechanisms of action of OLZ and PX.
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Affiliation(s)
- Marek Krzystanek
- Department and Clinic of Psychiatry and Psychotherapy, Medical University of Silesia, Katowice, Poland.
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Isolation and characterization of the plasma membrane from the yeast Pichia pastoris. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:1889-97. [PMID: 24680652 DOI: 10.1016/j.bbamem.2014.03.012] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 03/12/2014] [Accepted: 03/17/2014] [Indexed: 01/08/2023]
Abstract
Despite similarities of cellular membranes in all eukaryotes, every compartment displays characteristic and often unique features which are important for the functions of the specific organelles. In the present study, we biochemically characterized the plasma membrane of the methylotrophic yeast Pichia pastoris with emphasis on the lipids which form the matrix of this compartment. Prerequisite for this effort was the design of a standardized and reliable isolation protocol of the plasma membrane at high purity. Analysis of isolated plasma membrane samples from P. pastoris revealed an increase of phosphatidylserine and a decrease of phosphatidylcholine compared to bulk membranes. The amount of saturated fatty acids in the plasma membrane was higher than in total cell extracts. Ergosterol, the final product of the yeast sterol biosynthetic pathway, was found to be enriched in plasma membrane fractions, although markedly lower than in Saccharomyces cerevisiae. A further characteristic feature of the plasma membrane from P. pastoris was the enrichment of inositol phosphorylceramides over neutral sphingolipids, which accumulated in internal membranes. The detailed analysis of the P. pastoris plasma membrane is discussed in the light of cell biological features of this microorganism especially as a microbial cell factory for heterologous protein production.
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Purinergic stimulation of K+-dependent Na+/Ca2+ exchanger isoform 4 requires dual activation by PKC and CaMKII. Biosci Rep 2013; 33:BSR20130099. [PMID: 24224486 PMCID: PMC3867797 DOI: 10.1042/bsr20130099] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
K+-dependent Na+/Ca2+-exchanger isoform 4 (NCXK4) is one of the most broadly expressed members of the NCKX (K+-dependent Na+/Ca2+-exchanger) family. Recent data indicate that NCKX4 plays a critical role in controlling normal Ca2+ signal dynamics in olfactory and other neurons. Synaptic Ca2+ dynamics are modulated by purinergic regulation, mediated by ATP released from synaptic vesicles or from neighbouring glial cells. Previous studies have focused on modulation of Ca2+ entry pathways that initiate signalling. Here we have investigated purinergic regulation of NCKX4, a powerful extrusion pathway that assists in terminating Ca2+ signals. NCKX4 activity was stimulated by ATP through activation of the P2Y receptor signalling pathway. Stimulation required dual activation of PKC (protein kinase C) and CaMKII (Ca2+/calmodulin-dependent protein kinase II). Mutating T312, a putative PKC phosphorylation site on NCKX4, partially prevented purinergic stimulation. These data illustrate how purinergic regulation can shape the dynamics of Ca2+ signalling by activating a signal damping and termination pathway. Activity of the K+-dependent Na+/Ca2+-exchanger, NCKX4, is stimulated by purinergic signals that depend on dual activation of two protein kinase pathways. This regulation provides a novel mechanism to shape Ca2+ signaling and thus to have important impact on neuronal processes.
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Lone AM, Taskén K. Proinflammatory and immunoregulatory roles of eicosanoids in T cells. Front Immunol 2013; 4:130. [PMID: 23760108 PMCID: PMC3671288 DOI: 10.3389/fimmu.2013.00130] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 05/17/2013] [Indexed: 01/08/2023] Open
Abstract
Eicosanoids are inflammatory mediators primarily generated by hydrolysis of membrane phospholipids by phospholipase A2 to ω-3 and ω-6 C20 fatty acids that next are converted to leukotrienes (LTs), prostaglandins (PGs), prostacyclins (PCs), and thromboxanes (TXAs). The rate-limiting and tightly regulated lipoxygenases control synthesis of LTs while the equally well-controlled cyclooxygenases 1 and 2 generate prostanoids, including PGs, PCs, and TXAs. While many of the classical signs of inflammation such as redness, swelling, pain, and heat are caused by eicosanoid species with vasoactive, pyretic, and pain-inducing effects locally, some eicosanoids also regulate T cell functions. Here, we will review eicosanoid production in T cell subsets and the inflammatory and immunoregulatory functions of LTs, PGs, PCs, and TXAs in T cells.
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Affiliation(s)
- Anna Mari Lone
- Centre for Molecular Medicine Norway, Nordic EMBL Partnership, University of Oslo and Oslo University Hospital , Oslo , Norway ; Biotechnology Centre, University of Oslo , Oslo , Norway ; K.G. Jebsen Inflammation Research Centre, University of Oslo , Oslo , Norway
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Scott SA, Xiang Y, Mathews TP, Cho HP, Myers DS, Armstrong MD, Tallman KA, O'Reilly MC, Lindsley CW, Brown HA. Regulation of phospholipase D activity and phosphatidic acid production after purinergic (P2Y6) receptor stimulation. J Biol Chem 2013; 288:20477-87. [PMID: 23723068 DOI: 10.1074/jbc.m113.451708] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Phosphatidic acid (PA) is a lipid second messenger located at the intersection of several lipid metabolism and cell signaling events including membrane trafficking, survival, and proliferation. Generation of signaling PA has long been primarily attributed to the activation of phospholipase D (PLD). PLD catalyzes the hydrolysis of phosphatidylcholine into PA. A variety of both receptor-tyrosine kinase and G-protein-coupled receptor stimulations have been shown to lead to PLD activation and PA generation. This study focuses on profiling the PA pool upon P2Y6 receptor signaling manipulation to determine the major PA producing enzymes. Here we show that PLD, although highly active, is not responsible for the majority of stable PA being produced upon UDP stimulation of the P2Y6 receptor and that PA levels are tightly regulated. By following PA flux in the cell we show that PLD is involved in an initial increase in PA upon receptor stimulation; however, when PLD is blocked, the cell compensates by increasing PA production from other sources. We further delineate the P2Y6 signaling pathway showing that phospholipase Cβ3 (PLCβ3), PLCδ1, DGKζ and PLD are all downstream of receptor activation. We also show that DGKζ is a novel negative regulator of PLD activity in this system that occurs through an inhibitory mechanism with PKCα. These results further define the downstream events resulting in PA production in the P2Y6 receptor signaling pathway.
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Affiliation(s)
- Sarah A Scott
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA
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Razmara M, Heldin CH, Lennartsson J. Platelet-derived growth factor-induced Akt phosphorylation requires mTOR/Rictor and phospholipase C-γ1, whereas S6 phosphorylation depends on mTOR/Raptor and phospholipase D. Cell Commun Signal 2013; 11:3. [PMID: 23311350 PMCID: PMC3560233 DOI: 10.1186/1478-811x-11-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 01/09/2013] [Indexed: 11/10/2022] Open
Abstract
Mammalian target of rapamycin (mTOR) can be found in two multi-protein complexes, i.e. mTORC1 (containing Raptor) and mTORC2 (containing Rictor). Here, we investigated the mechanisms by which mTORC1 and mTORC2 are activated and their downstream targets in response to platelet-derived growth factor (PDGF)-BB treatment. Inhibition of phosphatidylinositol 3-kinase (PI3K) inhibited PDGF-BB activation of both mTORC1 and mTORC2. We found that in Rictor-null mouse embryonic fibroblasts, or after prolonged rapamycin treatment of NIH3T3 cells, PDGF-BB was not able to promote phosphorylation of Ser473 in the serine/threonine kinase Akt, whereas Thr308 phosphorylation was less affected, suggesting that Ser473 in Akt is phosphorylated in an mTORC2-dependent manner. This reduction in Akt phosphorylation did not influence the phosphorylation of the S6 protein, a well established protein downstream of mTORC1. Consistently, triciribine, an inhibitor of the Akt pathway, suppressed PDGF-BB-induced Akt phosphorylation without having any effect on S6 phosphorylation. Thus, mTORC2 does not appear to be upstream of mTORC1. We could also demonstrate that in Rictor-null cells the phosphorylation of phospholipase Cγ1 (PLCγ1) and protein kinase C (PKC) was impaired, and the PKCα protein levels strongly reduced. Furthermore, interfering with the PLCγ/Ca2+/PKC pathway inhibited PDGF-BB-induced Akt phosphorylation. In addition, PDGF-BB-induced activation of mTORC1, as measured by phosphorylation of the downstream S6 protein, was dependent on phospholipase D (PLD). It has been shown that Erk1/2 MAP-kinase directly phosphorylates and activates mTORC1; in partial agreement with this finding, we found that a Mek1/2 inhibitor delayed S6 phosphorylation in response to PDGF-BB, but it did not block it. Thus, whereas both mTORC1 and mTORC2 are activated in a PI3K-dependent manner, different additional signaling pathways are needed. mTORC1 is activated in a PLD-dependent manner and promotes phosphorylation of the S6 protein, whereas mTORC2, in concert with PLCγ signaling, promotes Akt phosphorylation.
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Affiliation(s)
- Masoud Razmara
- Ludwig Institute for Cancer Research, Science for life laboratory, Box 595, Biomedical Center, SE-751 24, Uppsala, Sweden.
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Zhao J, Wang X. Biochemical analysis of the interaction between phospholipase Dα1 and GTP-binding protein α-subunit from Arabidopsis thaliana. Methods Mol Biol 2013; 1043:21-35. [PMID: 23913032 DOI: 10.1007/978-1-62703-532-3_3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Phospholipase Ds (PLDs) play diverse roles in plant lipid metabolism and cellular signaling processes. The sole canonical G-protein α-subunit (Gα) in Arabidopsis also plays multiple roles in plant growth and cellular signaling processes. Interestingly, overlapping functions of PLD and Gα have been indicated in many cellular processes, including abscisic acid (ABA)-mediated stomata movement and water loss, gibberellic acid (GA)-regulated seed germination, and auxin signaling. This interaction between PLD and Gα has also been suggested in biochemical and physiological studies. Here we described the methods used for studying the interaction between the major PLD form PLDα1 and Gα. From pulldown experiments with purified bacterially expressed PLDα1 and Gα, co-immunoprecipitation of plant protein extract, and yeast two-hybrid assay, we showed that there is a physical interaction between PLDα1 and Gα, and identified a key DRY motif in PLDα1, which is an essential element for the interaction. The interaction of PLDα1 and Gα can be affected by factors like GTP or GDP, but it also affected PLD phospholipase activity and Gα GTPase activity in turn.
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Affiliation(s)
- Jian Zhao
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China
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Abstract
Neurons have characteristic dendritic arborization patterns that contribute to information processing. One essential component of dendritic arborization is the formation of a specific number of branches. Although intracellular pathways promoting dendritic growth and branching are being elucidated, the mechanisms that negatively regulate the branching of dendrites remain enigmatic. In this study, using gain-of-function and loss-of-function studies, we show that phospholipase D1 (PLD1) acts as a negative regulator of dendritic branching in cultured hippocampal neurons from embryonic day 18 rat embryos. Overexpression of wild-type PLD1 (WT-PLD1) decreases the complexity of dendrites, whereas knockdown or inhibition of PLD1 increases dendritic branching. We further demonstrated that PLD1 acts downstream of RhoA, one of the small Rho GTPases, to suppress dendritic branching. The restriction of dendritic branching by constitutively active RhoA (V14-RhoA) can be partially rescued by knockdown of PLD1. Moreover, the inhibition of dendritic branching by V14-RhoA and WT-PLD1 can be partially ameliorated by reducing the level of phosphatidic acid (PA), which is the enzymatic product of PLD1. Together, these results suggest that RhoA-PLD1-PA may represent a novel signaling pathway in the restriction of dendritic branching and may thus provide insight into the mechanisms of dendritic morphogenesis.
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Phospholipase D1 is an Important Regulator of bFGF-Induced Neurotrophin-3 Expression and Neurite Outgrowth in H19-7 Cells. Mol Neurobiol 2012; 45:507-19. [DOI: 10.1007/s12035-012-8268-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Accepted: 04/04/2012] [Indexed: 10/28/2022]
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Jang JH, Lee CS, Hwang D, Ryu SH. Understanding of the roles of phospholipase D and phosphatidic acid through their binding partners. Prog Lipid Res 2011; 51:71-81. [PMID: 22212660 DOI: 10.1016/j.plipres.2011.12.003] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Phospholipase D (PLD) is a phosphatidyl choline (PC)-hydrolyzing enzyme that generates phosphatidic acid (PA), a lipid second messenger that modulates diverse intracellular signaling. Through interactions with signaling molecules, both PLD and PA can mediate a variety of cellular functions, such as, growth/proliferation, vesicle trafficking, cytoskeleton modulation, development, and morphogenesis. Therefore, systemic approaches for investigating PLD networks including interrelationship between PLD and PA and theirs binding partners, such as proteins and lipids, can enhance fundamental knowledge of roles of PLD and PA in diverse biological processes. In this review, we summarize previously reported protein-protein and protein-lipid interactions of PLD and PA and their binding partners. In addition, we describe the functional roles played by PLD and PA in these interactions, and provide PLD network that summarizes these interactions. The PLD network suggests that PLD and PA could act as a decision maker and/or as a coordinator of signal dynamics. This viewpoint provides a turning point for understanding the roles of PLD-PA as a dynamic signaling hub.
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Affiliation(s)
- Jin-Hyeok Jang
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, Kyungbook 790-784, South Korea
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Itach SBS, Finklestein M, Etkovitz N, Breitbart H. Hyper-activated motility in sperm capacitation is mediated by phospholipase D-dependent actin polymerization. Dev Biol 2011; 362:154-61. [PMID: 22178154 DOI: 10.1016/j.ydbio.2011.12.002] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2011] [Revised: 11/22/2011] [Accepted: 12/01/2011] [Indexed: 12/15/2022]
Abstract
In order to fertilize the oocyte, sperm must undergo a series of biochemical changes in the female reproductive tract, known as capacitation. Once capacitated, spermatozoon can bind to the zona pellucida of the egg and undergo the acrosome reaction (AR), a process that enables its penetration and fertilization of the oocyte. Important processes that characterize sperm capacitation are actin polymerization and the development of hyper-activated motility (HAM). Previously, we showed that Phospholipase D (PLD)-dependent actin polymerization occurs during sperm capacitation, however the role of this process in sperm capacitation is not yet known. In the present study, we showed for the first time the involvement of PLD-dependent actin polymerization in sperm motility during mouse and human capacitation. Sperm incubated under capacitation conditions revealed a time dependent increase in actin polymerization and HAM. Inhibition of Phosphatidic Acid (PA) formation by PLD using butan-1-ol, inhibited actin polymerization and motility, as well as in vitro fertilization (IVF) and the ability of the sperm to undergo the AR. The inhibition of sperm HAM by low concentration of butan-1-ol is completely restored by adding PA, further indicating the involvement of PLD in these processes. Furthermore, exogenous PA enhanced rapid actin polymerization that was followed by a rise in the HAM, as well as an increased in IVF rate. In conclusion, our results demonstrate that PLD-dependent actin polymerization is a critical step needed for the development of HAM during mouse and human sperm capacitation.
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Affiliation(s)
- Sarit Bar-Sheshet Itach
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University Ramat-Gan, 52900, Israel
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Lanzafame AA, Christopoulos A, Mitchelson F. Cellular Signaling Mechanisms for Muscarinic Acetylcholine Receptors. ACTA ACUST UNITED AC 2011. [DOI: 10.3109/10606820308263] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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The progesterone receptor as a transcription factor regulates phospholipase D1 expression through independent activation of protein kinase A and Ras during 8-Br-cAMP-induced decidualization in human endometrial stromal cells. Biochem J 2011; 436:181-91. [PMID: 21284604 DOI: 10.1042/bj20101614] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Decidualization is a biological and morphological process occurring in hES (human endometrial stromal) cells. Previously, we reported that PLD1 (phospholipase D1) plays an important role in cAMP-induced decidualization of hES cells. In the present study, we focused on how PLD1 expression is up-regulated during decidualization. Treatment with PKA (protein kinase A) inhibitors (Rp-cAMP or H89) or a Ras inhibitor (manumycin) partially inhibited PLD1 expression and decidua formation in response to cAMP treatment. Interestingly, dual inhibition of PKA and Ras completely inhibited PLD1 expression and cAMP-induced decidualization. These results suggest that PLD1 expression during decidualization is controlled additively by PKA and Ras. The use of inhibitors showed that extracellular-signal-regulated kinase, a downstream effector of Ras, was required for PLD activation and the morphological changes during decidualization, but not for the increase in PLD1 protein. Next, to investigate the regulator of the PLD1 gene at the transcriptional level, a promoter assay using deletion mutants of the PLD1 promoter was performed; the result indicated that PR (progesterone receptor) was a possible regulator of the PLD1 gene. In addition, chromatin immunoprecipitation assays on the PLD1 promoter identified PR as a transcription factor for PLD1 expression during 8-Br-cAMP-induced decidualization. Taken together, our findings demonstrate that PKA and Ras are novel regulators of PLD1 expression and also identify PR as a transcription factor for PLD1 expression during the decidualization of hES cells.
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Lee YH, Uhm JS, Yoon SH, Kang JY, Kim EK, Kang BS, Min DS, Bae YS. The C-terminal domain of PLD2 participates in degradation of protein kinase CKII β subunit in human colorectal carcinoma cells. BMB Rep 2011; 44:572-7. [DOI: 10.5483/bmbrep.2011.44.9.572] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Nakka S, Guruprasad L. The imidazolidone analogs as phospholipase D1 inhibitors: analysis of the three-dimensional quantitative structure–activity relationship. Med Chem Res 2011. [DOI: 10.1007/s00044-011-9773-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Hodges RR, Guilbert E, Shatos MA, Natarajan V, Dartt DA. Phospholipase D1, but not D2, regulates protein secretion via Rho/ROCK in a Ras/Raf-independent, MEK-dependent manner in rat lacrimal gland. Invest Ophthalmol Vis Sci 2011; 52:2199-210. [PMID: 21212180 DOI: 10.1167/iovs.10-6209] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE A prior study showed that cholinergic agonists activate phospholipase D (PLD). The purpose of this study was to determine whether cholinergic agonists use the PLD pathway to alter protein secretion and to identify the molecular signaling components of this pathway in rat lacrimal gland acini. METHODS Rat lacrimal gland acini were isolated by collagenase digestion. Presence and localization of PLD1 and -2 were determined by immunofluorescence and Western blot experiments. Acini were incubated with adenoviruses overnight or the inhibitors 1-butanol, Y-27632, or C3 exotoxin before stimulation with the cholinergic agonist carbachol (Cch, 10(-4) M) for 5 minutes. Western blot analysis was performed for 20 minutes, and protein secretion was measured spectrophotometrically. Activation of ERK, MEK, Pyk2, Ras, and Raf was determined by Western blot analysis. RESULTS 1-Butanol increased Cch-stimulated protein secretion and decreased ERK activity. Incubation with catalytically inactive PLD1, but not catalytically inactive mutant PLD2 adenovirus, also increased Cch-stimulated protein secretion and decreased ERK activity. Inhibition of Rho with C3 exotoxin and a dominant negative Rho adenovirus and inhibition of ROCK with Y-27632 inhibited Cch-stimulated PLD1 activity, increased protein secretion, and decreased ERK activity. The association of PLD1 and ROCK increased with Cch stimulation, as determined by immunoprecipitation. PMA-stimulated ERK activity was also inhibited by 1-butanol. 1-Butanol had no effect on Cch-stimulated Pyk2, Ras, and Raf activity, but decreased MEK activity. CONCLUSIONS Cholinergic agonists activate PLD1 through Rho and ROCK, which in turn activate MEK and ERK, which attenuate protein secretion in freshly isolated epithelial cells.
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Affiliation(s)
- Robin R Hodges
- Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, 20 Staniford Street, Boston, MA 02114, USA.
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Lenoci L, Duvernay M, Satchell S, DiBenedetto E, Hamm HE. Mathematical model of PAR1-mediated activation of human platelets. MOLECULAR BIOSYSTEMS 2011; 7:1129-37. [DOI: 10.1039/c0mb00250j] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Faugaret D, Chouinard FC, Harbour D, El azreq MA, Bourgoin SG. An essential role for phospholipase D in the recruitment of vesicle amine transport protein-1 to membranes in human neutrophils. Biochem Pharmacol 2011; 81:144-56. [PMID: 20858461 DOI: 10.1016/j.bcp.2010.09.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Revised: 09/08/2010] [Accepted: 09/10/2010] [Indexed: 12/13/2022]
Abstract
Although phosphatidic acid (PA) regulates a wide variety of physiological processes, its targets remain poorly characterized in human neutrophils. By co-sedimentation with PA-containing vesicles we identified several PA-binding proteins including vesicle amine transport protein-1 (VAT-1), Annexin A3 (ANXA3), Rac2, Cdc42 and RhoG in neutrophil cytosol. Except for ANXA3, protein binding to PA-containing liposomes was calcium-independent. Cdc42 and RhoG preferentially interacted with PA whereas VAT-1 bound to PA or phosphatidylserine with the same affinity. VAT-1 translocated to neutrophil membranes upon N-formyl-methionyl-leucyl-phenylalanine (fMLF) stimulation. Inhibition of fMLF-induced PLD activity with the Src kinase inhibitor PP2, the selective inhibitor of PLD FIPI, or of PA formation with primary alcohols reduced VAT-1 translocation. In contrast, inhibition of PA hydrolysis with propranolol enhanced fMLF-mediated VAT-1 recruitment to membranes. PMA also redistributed VAT-1 to membranes in a PKC- and PLD-dependent manner. Though fMLF and PMA increased VAT-1 phosphorylation, different kinases appear to be involved. Cell fractionation revealed that a pool of VAT-1 was co-localized with primary, secondary and tertiary granules and plasma membrane markers in resting neutrophils. Stimulation with fMLF enhanced VAT-1 co-localization with CD32a, a plasma membrane marker. Confocal microscopy revealed that VAT-1 decorates granular structures at the cell periphery and double labeling with VAT-1/lactoferrin antibodies showed a partial co-localization with secondary granules in control and fMLF-stimulated cells. Characterization of these putative PA-binding proteins constitutes another step forward for a better understanding of the role of PLD-derived PA in neutrophil physiology.
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Affiliation(s)
- Delphine Faugaret
- Centre de Recherche en Rhumatologie et Immunologie, Centre de recherche du CHUQ-CHUL et Faculté de Médecine de l'Université Laval, 2705 Boulevard Laurier, local T1-49, Québec, QC, G1V 4G2, Canada.
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Patel RB, Kotha SR, Sherwani SI, Sliman SM, Gurney TO, Loar B, Butler SO, Morris AJ, Marsh CB, Parinandi NL. Pulmonary fibrosis inducer, bleomycin, causes redox-sensitive activation of phospholipase D and cytotoxicity through formation of bioactive lipid signal mediator, phosphatidic acid, in lung microvascular endothelial cells. Int J Toxicol 2010; 30:69-90. [PMID: 21131602 DOI: 10.1177/1091581810388850] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The mechanisms of lung microvascular complications and pulmonary hypertension known to be associated with idiopathic pulmonary fibrosis (IPF), a debilitating lung disease, are not known. Therefore, we investigated whether bleomycin, the widely used experimental IPF inducer, would be capable of activating phospholipase D (PLD) and generating the bioactive lipid signal-mediator phosphatidic acid (PA) in our established bovine lung microvascular endothelial cell (BLMVEC) model. Our results revealed that bleomycin induced the activation of PLD and generation of PA in a dose-dependent (5, 10, and 100 µg) and time-dependent (2-12 hours) fashion that were significantly attenuated by the PLD-specific inhibitor, 5-fluoro-2-indolyl des-chlorohalopemide (FIPI). PLD activation and PA generation induced by bleomycin (5 µg) were significantly attenuated by the thiol protectant (N-acetyl-L-cysteine), antioxidants, and iron chelators suggesting the role of reactive oxygen species (ROS), lipid peroxidation, and iron therein. Furthermore, our study demonstrated the formation of ROS and loss of glutathione (GSH) in cells following bleomycin treatment, confirming oxidative stress as a key player in the bleomycin-induced PLD activation and PA generation in ECs. More noticeably, PLD activation and PA generation were observed to happen upstream of bleomycin-induced cytotoxicity in BLMVECs, which was protected by FIPI. This was also supported by our current findings that exposure of cells to exogenous PA led to internalization of PA and cytotoxicity in BLMVECs. For the first time, this study revealed novel mechanism of the bleomycin-induced redox-sensitive activation of PLD that led to the generation of PA, which was capable of inducing lung EC cytotoxicity, thus suggesting possible bioactive lipid-signaling mechanism/mechanisms of microvascular disorders encountered in IPF.
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Affiliation(s)
- Rishi B Patel
- Lipid Signaling, Lipidomics, and Vasculotoxicity Laboratory, Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, 43210, USA
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Protein kinase Cdelta-mediated phosphorylation of phospholipase D controls integrin-mediated cell spreading. Mol Cell Biol 2010; 30:5086-98. [PMID: 20733000 DOI: 10.1128/mcb.00443-10] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Integrin signaling plays critical roles in cell adhesion, spreading, and migration, and it is generally accepted that to regulate these integrin functions accurately, localized actin remodeling is required. However, the molecular mechanisms that control the targeting of actin regulation molecules to the proper sites are unknown. We previously demonstrated that integrin-mediated cell spreading and migration on fibronectin are dependent on the localized activation of phospholipase D (PLD). However, the mechanism underlying PLD activation by integrin is largely unknown. Here we demonstrate that protein kinase Cδ (PKCδ) is required for integrin-mediated PLD signaling. After integrin stimulation, PKCδ is activated and translocated to the edges of lamellipodia, where it colocalizes with PLD2. The abrogation of PKCδ activity inhibited integrin-induced PLD activation and cell spreading. Finally, we show that Thr566 of PLD2 is directly phosphorylated by PKCδ and that PLD2 mutation in this region prevents PLD2 activation, PLD2 translocation to the edge of lamellipodia, Rac translocation, and cell spreading after integrin activation. Together, these results suggest that PKCδ is a primary regulator of integrin-mediated PLD activation via the direct phosphorylation of PLD, which is essential for directing integrin-induced cell spreading.
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A comprehensive model that explains the regulation of phospholipase D2 activity by phosphorylation-dephosphorylation. Mol Cell Biol 2010; 30:2251-63. [PMID: 20176813 DOI: 10.1128/mcb.01239-09] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We report here that the enzymatic activity of phospholipase D2 (PLD2) is regulated by phosphorylation-dephosphorylation. Phosphatase treatment of PLD2-overexpressing cells showed a biphasic nature of changes in activity that indicated the existence of "activator" and "inhibitory" sites. We identified three kinases capable of phosphorylating PLD2 in vitro-epidermal growth factor receptor (EGFR), JAK3, and Src (with JAK3 reported for the first time in this study)-that phosphorylate an inhibitory, an activator, and an ambivalent (one that can yield either effect) site, respectively. Mass spectrometry analyses indicated the target of each of these kinases as Y(296) for EGFR, Y(415) for JAK3, and Y(511) for Src. The extent to which each site is activated or inhibited depends on the cell type considered. In COS-7, cells that show the highest level of PLD2 activity, the Y(415) is a prominent site, and JAK3 compensates the negative modulation by EGFR on Y(296). In MCF-7, cells that show the lowest level of PLD2 activity, the converse is the case, with Y(296) unable to compensate the positive modulation by Y(415). MTLn3, with medium to low levels of lipase activity, show an intermediate pattern of regulation but closer to MCF-7 than to COS-7 cells. The negative effect of EGFR on the two cancer cell lines MTLn3 and MCF-7 is further proven by RNA silencing experiments that yield COS-7 showing lower PLD2 activity, and MTLn3 and MCF-7 cells showing an elevated activity. MCF-7 is a cancer cell line derived from a low-aggressive/invasive form of breast cancer that has relatively low levels of PLD activity. We propose that PLD2 activity is low in the breast cancer cell line MCF-7 because it is kept downregulated by tyrosyl phosphorylation of Y(296) by EGFR kinase. Thus, phosphorylation of PLD2-Y(296) could be the signal for lowering the level of PLD2 activity in transformed cells with low invasive capabilities.
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Kim NY, Kim TH, Lee E, Patra N, Lee J, Shin MO, Kwack SJ, Park KL, Han SY, Kang TS, Kim SH, Lee BM, Kim HS. Functional role of phospholipase D (PLD) in di(2-ethylhexyl) phthalate-induced hepatotoxicity in Sprague-Dawley rats. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2010; 73:1560-1569. [PMID: 20954081 DOI: 10.1080/15287394.2010.511582] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Phospholipase D (PLD) is an enzyme that catalyzes the hydrolysis of phosphatidyl choline (PC) to generate phosphatidic acid (PA) and choline. PLD is believed to play an important role in cell proliferation, survival signaling, cell transformation, and tumor progression. However, it remains to be determined whether enhanced expression of PLD in liver is sufficient to induce hepatotoxicity. The aim of this study was to investigate the possible role of PLD in di(2-ethylhexyl) phthalate (DEHP)-induced hepatotoxicity in Sprague-Dawley rats. The phthalate, DEHP (500 mg/kg/d), was administered orally, daily to prepubertal rats (4 wk of age, weighing approximately 70-90 g) for 1, 7, or 28 d. In this study, protein expression levels of PLD1/2, peroxisome proliferator-activated receptor (PPAR), and cytochrome P-450 (CYP) were determined by Western blot analysis using specific antibodies. Liver weight was significantly increased in the DEHP treatment groups. Immunohistochemical analysis demonstrated that DEHP produced strong staining of proliferating cell nuclear antigen (PCNA) at 28 d of exposure, suggestive of hepatocyte proliferation. A significant rise in PLD1/2 expression was observed in liver of DEHP-exposed rats after 7 d. Further, PPARα, constitutive androstane receptor (CAR), pregnane X receptor (PXR), and CYP2B1 protein expression levels were markedly elevated in DEHP-treated groups. Our results suggest that DEHP significantly enhanced the expression of PLD, which may be correlated with PPARα-induced hepatotoxicity through a complex interaction with nuclear receptors including CAR and PXR.
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Affiliation(s)
- Na Young Kim
- Laboratory of Molecular Toxicology, College of Pharmacy, Pusan National University, Busan, South Korea
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Kim M, Moon C, Kim H, Shin MK, Min DS, Shin T. Developmental levels of phospholipase D isozymes in the brain of developing rats. Acta Histochem 2010; 112:81-91. [PMID: 19010519 DOI: 10.1016/j.acthis.2008.09.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2008] [Revised: 09/03/2008] [Accepted: 09/15/2008] [Indexed: 11/18/2022]
Abstract
The developmental levels of phospholipase D (PLD) isozymes was examined in the cerebrum and hindbrain of the developing rat to better understand the involvement of PLD in brain development. Western blot analysis of PLD in the cerebrum showed that PLD1, a major PLD isoform in the brain, was detected weakly in the cerebrum at day 17 embryonic stage and its levels gradually increased until postnatal day 35 and remained unaltered thereafter. In the hindbrain, comprising the cerebellum and pons, the peak level of PLD1 was detected at 21 days postnatally and declined progressively thereafter. The level of PLD2 in both the cerebrum and hindbrain was minimal compared to that of PLD1. Based on immunohistochemistry, PLD was detected in some neurons and glial cells in the cerebrum. In the hindbrain, PLD was found in some Purkinje cells and some cells of the molecular layer, as well as glial cells, consistent with the results obtained from Western blot analysis. These findings suggest that PLD may differentially play a role in the course of early development of the brain, with special reference to the cerebrum and hindbrain, in rats.
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Affiliation(s)
- Mia Kim
- Department of Veterinary Anatomy, Applied Radiological Science Research Institute, Cheju National University, Jeju, South Korea
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