151
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Abstract
Gαq signals with phospholipase C-β (PLC-β) to modify behavior in response to an agonist-bound GPCR. While the fundamental steps which prime Gαq to interact with PLC-β have been identified, questions remain concerning signal strength with PLC-β and other effectors. Gαq is generally viewed to function as a simple ON and OFF switch for its effector, dependent on the binding of GTP or GDP. However, Gαq does not have a single effector, Gαq has many different effectors. Furthermore, select effectors also regulate Gαq activity. PLC-β is a lipase and a GTPase activating protein (GAP) selective for Gαq. The contribution of G protein regulating activity to signal amplitude remains unclear. The unique PLC-β coiled-coil domain is essential for maximum Gαq response, both lipase and GAP. Nonetheless, coiled-coil domain associations necessary to maximum response have not been revealed by the structural approach. This review discusses progress towards understanding the basis for signal strength with PLC-β and other effectors. Shared and effector-specific interactions have been identified. Finally, the evidence for allosteric regulation of lipase stimulation by protein kinase C, the membrane, phosphatidic acid, phosphatidylinositol-4, 5-bisphosphate and GPCR is explored. Endogenous allosteric regulators can suppress or enhance maximum lipase stimulation dependent on the PLC-β coiled-coil domain. A better understanding of allosteric modulation may therefore identify a wealth of new targets to regulate signal strength and behavior.
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Affiliation(s)
- Irene Litosch
- Department of Molecular and Cellular Pharmacology, Miller School of Medicine University of Miami, Miami, FL 33101-6189, USA.
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152
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Bu Y, Diehl JA. PERK Integrates Oncogenic Signaling and Cell Survival During Cancer Development. J Cell Physiol 2016; 231:2088-96. [PMID: 26864318 DOI: 10.1002/jcp.25336] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 02/08/2016] [Indexed: 12/11/2022]
Abstract
Unfolded protein responses (UPR), consisting of three major transducers PERK, IRE1, and ATF6, occur in the midst of a variety of intracellular and extracellular challenges that perturb protein folding in the endoplasmic reticulum (ER). ER stress occurs and is thought to be a contributing factor to a number of human diseases, including cancer, neurodegenerative disorders, and various metabolic syndromes. In the context of neoplastic growth, oncogenic stress resulting from dysregulation of oncogenes such as c-Myc, Braf(V600E) , and HRAS(G12V) trigger the UPR as an adaptive strategy for cancer cell survival. PERK is an ER resident type I protein kinase harboring both pro-apoptotic and pro-survival capabilities. PERK, as a coordinator through its downstream substrates, reprograms cancer gene expression to facilitate survival in response to oncogenes and microenvironmental challenges, such as hypoxia, angiogenesis, and metastasis. Herein, we discuss how PERK kinase engages in tumor initiation, transformation, adaption microenvironmental stress, chemoresistance and potential opportunities, and potential opportunities for PERK targeted therapy. J. Cell. Physiol. 231: 2088-2096, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Yiwen Bu
- Department of Biochemistry and Molecular Biology, Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina
| | - J Alan Diehl
- Department of Biochemistry and Molecular Biology, Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina
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153
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MAEDA TOYONOBU, YUZAWA SATOSHI, SUZUKI ATSUKO, BABA YUH, NISHIMURA YUKIO, KATO YASUMASA. RhoA mediates the expression of acidic extracellular pH-induced matrix metalloproteinase-9 mRNA through phospholipase D1 in mouse metastatic B16-BL6 melanoma cells. Int J Oncol 2016; 48:1251-7. [DOI: 10.3892/ijo.2016.3322] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 12/10/2015] [Indexed: 11/05/2022] Open
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154
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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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155
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Park MH, Bae SS, Choi KY, Min DS. Phospholipase D2 promotes degradation of hypoxia-inducible factor-1α independent of lipase activity. Exp Mol Med 2015; 47:e196. [PMID: 26611735 PMCID: PMC4673472 DOI: 10.1038/emm.2015.87] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 08/19/2015] [Accepted: 09/08/2015] [Indexed: 01/04/2023] Open
Abstract
Hypoxia-inducible factor-1α (HIF-1α) is a key transcriptional mediator that coordinates the expression of various genes involved in tumorigenesis in response to changes in oxygen tension. The stability of HIF-1α protein is determined by oxygen-dependent prolyl hydroxylation, which is required for binding of the von Hippel-Lindau protein (VHL), the recognition component of an E3 ubiquitin ligase that targets HIF-1α for ubiquitination and degradation. Here, we demonstrate that PLD2 protein itself interacts with HIF-1α, prolyl hydroxylase (PHD) and VHL to promote degradation of HIF-1α via the proteasomal pathway independent of lipase activity. PLD2 increases PHD2-mediated hydroxylation of HIF-1α by increasing the interaction of HIF-1α with PHD2. Moreover, PLD2 promotes VHL-dependent HIF-1α degradation by accelerating the association between VHL and HIF-1α. The interaction of the pleckstrin homology domain of PLD2 with HIF-1α also promoted degradation of HIF-1α and decreased expression of its target genes. These results indicate that PLD2 negatively regulates the stability of HIF-1α through the dynamic assembly of HIF-1α, PHD2 and VHL.
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Affiliation(s)
- Mi Hee Park
- Department of Molecular Biology, College of Natural Science, Pusan National University, Busan, Republic of Korea
| | - Sun Sik Bae
- Department of Pharmacology, School of Medicine, Pusan National University, Busan, Republic of Korea
| | - Kang-Yell Choi
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, Republic of Korea
- Translational Research Center for Protein Function Control, Yonsei University, Seoul, Republic of Korea
| | - Do Sik Min
- Department of Molecular Biology, College of Natural Science, Pusan National University, Busan, Republic of Korea
- Translational Research Center for Protein Function Control, Yonsei University, Seoul, Republic of Korea
- Genetic Engineering Institute, Pusan National University, Busan, Republic of Korea
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156
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Lee CS, Kim JM, Ghim J, Suh PG, Ryu SH. GTP-dependent interaction between phospholipase D and dynamin modulates fibronectin-induced cell spreading. Cell Signal 2015; 27:2363-70. [PMID: 26341143 DOI: 10.1016/j.cellsig.2015.08.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 08/30/2015] [Indexed: 11/27/2022]
Abstract
Phospholipase D (PLD) is one of the key enzymes to mediate a variety of cellular phenomena including endocytosis, actin rearrangement, proliferation, differentiation, and migration. Dynamin as a PLD-interacting partner is a large GTP binding protein that has been considered a mechanochemical enzyme involved in endocytosis by hydrolyzing GTP. Although both PLD and dynamin have been implicated in the regulation of actin cytoskeleton, it is not known how they have a link to regulate fibronectin (FN)-induced cell spreading. Furthermore, it is unknown whether dynamin can work as a GTP-dependent regulator through its interaction with other proteins. Here, we demonstrate that PLD can be regulated by dynamin in a GTP-dependent manner and that this is critical for FN-mediated cell spreading. First, we verified that GTP-loaded dynamin can mediate the cell spreading by FN by using dynamin's GTP binding deficient mutant (K44A). Also, we confirmed that blocking the PLD activity inhibited FN-induced cell spreading, not cell adhesion. Moreover, PLD interacted with dynamin in a GTP-dependent manner in FN signaling, and this interaction was crucial for FN-induced PLD activation and cell spreading. Also, we found that PLD mutant (R128K) that didn't have GAP activity increased the GTP-dependent interaction between PLD and dynamin; it also increased PLD activity and cell spreading. These findings suggest that the observed increase in PLD activity was through boosting the binding of PLD with dynamin and it facilitated FN-induced cell spreading. These results imply that GTP-loaded dynamin, like a small GTPase could mediate a "switch on" signaling via interaction with PLD that has a role as an effector.
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Affiliation(s)
- Chang Sup Lee
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang 790-784, South Korea
| | - Jong Min Kim
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang 790-784, South Korea
| | - Jaewang Ghim
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang 790-784, South Korea
| | - Pann-Ghill Suh
- School of Life Science, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, South Korea
| | - Sung Ho Ryu
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang 790-784, South Korea.
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157
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Litosch I. Regulating G protein activity by lipase-independent functions of phospholipase C. Life Sci 2015; 137:116-24. [DOI: 10.1016/j.lfs.2015.07.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 06/18/2015] [Accepted: 07/22/2015] [Indexed: 11/27/2022]
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158
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Role of phospholipases D1 and 2 in astroglial proliferation: effects of specific inhibitors and genetic deletion. Eur J Pharmacol 2015; 761:398-404. [DOI: 10.1016/j.ejphar.2015.05.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 04/11/2015] [Accepted: 05/08/2015] [Indexed: 01/08/2023]
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159
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Bedia C, Dalmau N, Jaumot J, Tauler R. Phenotypic malignant changes and untargeted lipidomic analysis of long-term exposed prostate cancer cells to endocrine disruptors. ENVIRONMENTAL RESEARCH 2015; 140:18-31. [PMID: 25817993 DOI: 10.1016/j.envres.2015.03.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 03/05/2015] [Accepted: 03/16/2015] [Indexed: 05/10/2023]
Abstract
Endocrine disruptors (EDs) are a class of environmental toxic molecules able to interfere with the normal hormone metabolism. Numerous studies involve EDs exposure to initiation and development of cancers, including prostate cancer. In this work, three different EDs (aldrin, aroclor 1254 and chlorpyrifos (CPF)) were investigated as potential inducers of a malignant phenotype in DU145 prostate cancer cells after a chronic exposure. Epithelial to mesenchymal transition (EMT) induction, proliferation, migration, colony formation and release of metalloproteinase 2 (MMP-2) were analyzed in 50-day exposed cells to the selected EDs. As a result, aldrin and CPF exposure led to an EMT induction (loss of 16% and 14% of E-cadherin levels, respectively, compared to the unexposed cells). Aroclor and CPF presented an increased migration (134% and 126%, respectively), colony formation (204% and 144%, respectively) and MMP-2 release (137% in both cases) compared to the unexposed cells. An untargeted lipidomic analysis was performed to decipher the lipids involved in the observed transformations. As general results, aldrin exposure showed a global decrease in phospholipids and sphingolipids, and aroclor and CPF showed an increase of certain phospholipids, glycosphingolipids as well as a remarkable increase of some cardiolipin species. Furthermore, the three exposures resulted in an increase of some triglyceride species. In conclusion, some significant changes in lipids were identified and thus we postulate that some lipid compounds and lipid metabolic pathways could be involved in the acquisition of the malignant phenotype in exposed prostate cancer cells to the selected EDs.
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Affiliation(s)
- Carmen Bedia
- Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA-CSIC), c/ Jordi Girona 18-24, 08034 Barcelona, Spain.
| | - Núria Dalmau
- Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA-CSIC), c/ Jordi Girona 18-24, 08034 Barcelona, Spain.
| | - Joaquim Jaumot
- Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA-CSIC), c/ Jordi Girona 18-24, 08034 Barcelona, Spain.
| | - Romà Tauler
- Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA-CSIC), c/ Jordi Girona 18-24, 08034 Barcelona, Spain.
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160
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De Marothy MT, Elofsson A. Marginally hydrophobic transmembrane α-helices shaping membrane protein folding. Protein Sci 2015; 24:1057-74. [PMID: 25970811 DOI: 10.1002/pro.2698] [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] [Received: 03/30/2015] [Accepted: 04/24/2015] [Indexed: 01/12/2023]
Abstract
Cells have developed an incredible machinery to facilitate the insertion of membrane proteins into the membrane. While we have a fairly good understanding of the mechanism and determinants of membrane integration, more data is needed to understand the insertion of membrane proteins with more complex insertion and folding pathways. This review will focus on marginally hydrophobic transmembrane helices and their influence on membrane protein folding. These weakly hydrophobic transmembrane segments are by themselves not recognized by the translocon and therefore rely on local sequence context for membrane integration. How can such segments reside within the membrane? We will discuss this in the light of features found in the protein itself as well as the environment it resides in. Several characteristics in proteins have been described to influence the insertion of marginally hydrophobic helices. Additionally, the influence of biological membranes is significant. To begin with, the actual cost for having polar groups within the membrane may not be as high as expected; the presence of proteins in the membrane as well as characteristics of some amino acids may enable a transmembrane helix to harbor a charged residue. The lipid environment has also been shown to directly influence the topology as well as membrane boundaries of transmembrane helices-implying a dynamic relationship between membrane proteins and their environment.
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Affiliation(s)
- Minttu T De Marothy
- Department of Biochemistry and Biophysics Science for Life Laboratory, Stockholm University, Solna, SE-171 21, Sweden
| | - Arne Elofsson
- Department of Biochemistry and Biophysics Science for Life Laboratory, Stockholm University, Solna, SE-171 21, Sweden
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161
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Taylor HE, Simmons GE, Mathews TP, Khatua AK, Popik W, Lindsley CW, D’Aquila RT, Brown HA. Phospholipase D1 Couples CD4+ T Cell Activation to c-Myc-Dependent Deoxyribonucleotide Pool Expansion and HIV-1 Replication. PLoS Pathog 2015; 11:e1004864. [PMID: 26020637 PMCID: PMC4447393 DOI: 10.1371/journal.ppat.1004864] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 04/07/2015] [Indexed: 12/25/2022] Open
Abstract
Quiescent CD4+ T cells restrict human immunodeficiency virus type 1 (HIV-1) infection at early steps of virus replication. Low levels of both deoxyribonucleotide triphosphates (dNTPs) and the biosynthetic enzymes required for their de novo synthesis provide one barrier to infection. CD4+ T cell activation induces metabolic reprogramming that reverses this block and facilitates HIV-1 replication. Here, we show that phospholipase D1 (PLD1) links T cell activation signals to increased HIV-1 permissivity by triggering a c-Myc-dependent transcriptional program that coordinates glucose uptake and nucleotide biosynthesis. Decreasing PLD1 activity pharmacologically or by RNA interference diminished c-Myc-dependent expression during T cell activation at the RNA and protein levels. PLD1 inhibition of HIV-1 infection was partially rescued by adding exogenous deoxyribonucleosides that bypass the need for de novo dNTP synthesis. Moreover, the data indicate that low dNTP levels that impact HIV-1 restriction involve decreased synthesis, and not only increased catabolism of these nucleotides. These findings uncover a unique mechanism of action for PLD1 inhibitors and support their further development as part of a therapeutic combination for HIV-1 and other viral infections dependent on host nucleotide biosynthesis.
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Affiliation(s)
- Harry E. Taylor
- Northwestern HIV Translational Research Center, Division of Infectious Diseases, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
- * E-mail: (HET); (HAB)
| | - Glenn E. Simmons
- Department of Molecular Genetics, University of Texas, Southwestern Medical Center, Dallas, Texas, United States of America
| | - Thomas P. Mathews
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Atanu K. Khatua
- Meharry Medical College, Center for AIDS Health Disparities Research, Nashville, Tennessee, United States of America
| | - Waldemar Popik
- Meharry Medical College, Center for AIDS Health Disparities Research, Nashville, Tennessee, United States of America
| | - Craig W. Lindsley
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Chemistry, Vanderbilt University, Nashville, Tennesee, United States of America
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Richard T. D’Aquila
- Northwestern HIV Translational Research Center, Division of Infectious Diseases, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - H. Alex Brown
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- * E-mail: (HET); (HAB)
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162
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Mathews TP, Hill S, Rose KL, Ivanova PT, Lindsley CW, Brown HA. Human phospholipase D activity transiently regulates pyrimidine biosynthesis in malignant gliomas. ACS Chem Biol 2015; 10:1258-68. [PMID: 25646564 DOI: 10.1021/cb500772c] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Cancer cells reorganize their metabolic pathways to fuel demanding rates of proliferation. Oftentimes, these metabolic phenotypes lie downstream of prominent oncogenes. The lipid signaling molecule phosphatidic acid (PtdOH), which is produced by the hydrolytic enzyme phospholipase D (PLD), has been identified as a critical regulatory molecule for oncogenic signaling in many cancers. In an effort to identify novel regulatory mechanisms for PtdOH, we screened various cancer cell lines, assessing whether treatment of cancer models with PLD inhibitors altered production of intracellular metabolites. Preliminary findings lead us to focus on how deoxyribonucleoside triphosphates (dNTPs) are altered upon PLD inhibitor treatment in gliomas. Using a combination of proteomics and small molecule intracellular metabolomics, we show herein that PtdOH acutely regulates the production of these pyrimidine metabolites through activation of CAD via mTOR signaling pathways independently of Akt. These changes are responsible for decreases in dNTP production after PLD inhibitor treatment. Our data identify a novel regulatory role for PLD activity in specific cancer types.
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Affiliation(s)
- Thomas P. Mathews
- Department of Pharmacology
and The Vanderbilt Ingram Cancer Center, ‡The Vanderbilt Center
for Neuroscience Drug Discovery, Vanderbilt University Medical Center, §Department of Chemistry, ∥The Vanderbilt Institute
of Chemical Biology, ⊥The Vanderbilt Mass Spectrometry Research Center, and #Department of Biochemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Salisha Hill
- Department of Pharmacology
and The Vanderbilt Ingram Cancer Center, ‡The Vanderbilt Center
for Neuroscience Drug Discovery, Vanderbilt University Medical Center, §Department of Chemistry, ∥The Vanderbilt Institute
of Chemical Biology, ⊥The Vanderbilt Mass Spectrometry Research Center, and #Department of Biochemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Kristie L. Rose
- Department of Pharmacology
and The Vanderbilt Ingram Cancer Center, ‡The Vanderbilt Center
for Neuroscience Drug Discovery, Vanderbilt University Medical Center, §Department of Chemistry, ∥The Vanderbilt Institute
of Chemical Biology, ⊥The Vanderbilt Mass Spectrometry Research Center, and #Department of Biochemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Pavlina T. Ivanova
- Department of Pharmacology
and The Vanderbilt Ingram Cancer Center, ‡The Vanderbilt Center
for Neuroscience Drug Discovery, Vanderbilt University Medical Center, §Department of Chemistry, ∥The Vanderbilt Institute
of Chemical Biology, ⊥The Vanderbilt Mass Spectrometry Research Center, and #Department of Biochemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Craig W. Lindsley
- Department of Pharmacology
and The Vanderbilt Ingram Cancer Center, ‡The Vanderbilt Center
for Neuroscience Drug Discovery, Vanderbilt University Medical Center, §Department of Chemistry, ∥The Vanderbilt Institute
of Chemical Biology, ⊥The Vanderbilt Mass Spectrometry Research Center, and #Department of Biochemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - H. Alex Brown
- Department of Pharmacology
and The Vanderbilt Ingram Cancer Center, ‡The Vanderbilt Center
for Neuroscience Drug Discovery, Vanderbilt University Medical Center, §Department of Chemistry, ∥The Vanderbilt Institute
of Chemical Biology, ⊥The Vanderbilt Mass Spectrometry Research Center, and #Department of Biochemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
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163
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Wildburger NC, Wood PL, Gumin J, Lichti CF, Emmett MR, Lang FF, Nilsson CL. ESI-MS/MS and MALDI-IMS Localization Reveal Alterations in Phosphatidic Acid, Diacylglycerol, and DHA in Glioma Stem Cell Xenografts. J Proteome Res 2015; 14:2511-9. [PMID: 25880480 DOI: 10.1021/acs.jproteome.5b00076] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Glioblastoma (GBM) is the most common adult primary brain tumor. Despite aggressive multimodal therapy, the survival of patients with GBM remains dismal. However, recent evidence has demonstrated the promise of bone marrow-derived mesenchymal stem cells (BM-hMSCs) as a therapeutic delivery vehicle for anti-glioma agents due to their ability to migrate or home to human gliomas. While several studies have demonstrated the feasibility of harnessing the homing capacity of BM-hMSCs for targeted delivery of cancer therapeutics, it is now also evident, based on clinically relevant glioma stem cell (GSC) models of GBMs, that BM-hMSCs demonstrate variable tropism toward these tumors. In this study, we compared the lipid environment of GSC xenografts that attract BM-hMSCs (N = 9) with those that do not attract (N = 9) to identify lipid modalities that are conducive to homing of BM-hMSC to GBMs. We identified lipids directly from tissue by matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) and electrospray ionization-tandem mass spectrometry (ESI-MS/MS) of lipid extracts. Several species of signaling lipids, including phosphatidic acid (PA 36:2, PA 40:5, PA 42:5, and PA 42:7) and diacylglycerol (DAG 34:0, DAG 34:1, DAG 36:1, DAG 38:4, DAG 38:6, and DAG 40:6), were lower in attracting xenografts. Molecular lipid images showed that PA (36:2), DAG (40:6), and docosahexaenoic acid (DHA) were decreased within tumor regions of attracting xenografts. Our results provide the first evidence for lipid signaling pathways and lipid-mediated tumor inflammatory responses in the homing of BM-hMSCs to GSC xenografts. Our studies provide new fundamental knowledge on the molecular correlates of the differential homing capacity of BM-hMSCs toward GSC xenografts.
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Affiliation(s)
| | - Paul L Wood
- ∥Department of Physiology and Pharmacology, Lincoln Memorial University, 6965 Cumberland Gap Parkway, Harrogate, Tennessee 37752, United States
| | | | - Cheryl F Lichti
- §UTMB Cancer Center, University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas 77555-1074, United States
| | - Mark R Emmett
- §UTMB Cancer Center, University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas 77555-1074, United States
| | | | - Carol L Nilsson
- §UTMB Cancer Center, University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas 77555-1074, United States
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164
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Nelson RK, Frohman MA. Physiological and pathophysiological roles for phospholipase D. J Lipid Res 2015; 56:2229-37. [PMID: 25926691 DOI: 10.1194/jlr.r059220] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Indexed: 11/20/2022] Open
Abstract
Individual members of the mammalian phospholipase D (PLD) superfamily undertake roles that extend from generating the second messenger signaling lipid, phosphatidic acid, through hydrolysis of the membrane phospholipid, phosphatidylcholine, to functioning as an endonuclease to generate small RNAs and facilitating membrane vesicle trafficking through seemingly nonenzymatic mechanisms. With recent advances in genome-wide association studies, RNA interference screens, next-generation sequencing approaches, and phenotypic analyses of knockout mice, roles for PLD family members are being uncovered in autoimmune, infectious neurodegenerative, and cardiovascular disease, as well as in cancer. Some of these disease settings pose opportunities for small molecule inhibitory therapeutics, which are currently in development.
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Affiliation(s)
- Rochelle K Nelson
- Graduate Program in Physiology and Biophysics Stony Brook University, Stony Brook, NY
| | - Michael A Frohman
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY
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165
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Frohman MA. The phospholipase D superfamily as therapeutic targets. Trends Pharmacol Sci 2015; 36:137-44. [PMID: 25661257 DOI: 10.1016/j.tips.2015.01.001] [Citation(s) in RCA: 147] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 01/11/2015] [Accepted: 01/13/2015] [Indexed: 01/03/2023]
Abstract
The phospholipase D (PLD) lipid-signaling enzyme superfamily has long been studied for its roles in cell communication and a wide range of cell biological processes. With the advent of loss-of-function genetic mouse models that have revealed that PLD1 and PLD2 ablation is overtly tolerable, small-molecule PLD1/2 inhibitors that do not cause unacceptable clinical toxicity, a PLD2 polymorphism that has been linked to altered physiology, and growing delineation of processes that are subtly altered in mice lacking PLD1/2 activity, the stage is being set for assessment of PLD1/2 inhibition for therapeutic purposes. Based on findings to date, PLD1/2 inhibition may be of more utility in acute rather than chronic settings, although this generalization will depend on the specific risks and benefits in each disease setting.
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Affiliation(s)
- Michael A Frohman
- Department of Pharmacological Sciences and the Center for Developmental Genetics, 438 Centers for Molecular Medicine, Stony Brook University, Stony Brook, NY 11794-5140, USA.
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