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Korbecki J, Bosiacki M, Pilarczyk M, Gąssowska-Dobrowolska M, Jarmużek P, Szućko-Kociuba I, Kulik-Sajewicz J, Chlubek D, Baranowska-Bosiacka I. Phospholipid Acyltransferases: Characterization and Involvement of the Enzymes in Metabolic and Cancer Diseases. Cancers (Basel) 2024; 16:2115. [PMID: 38893234 PMCID: PMC11171337 DOI: 10.3390/cancers16112115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 05/23/2024] [Accepted: 05/28/2024] [Indexed: 06/21/2024] Open
Abstract
This review delves into the enzymatic processes governing the initial stages of glycerophospholipid (phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine) and triacylglycerol synthesis. The key enzymes under scrutiny include GPAT and AGPAT. Additionally, as most AGPATs exhibit LPLAT activity, enzymes participating in the Lands cycle with similar functions are also covered. The review begins by discussing the properties of these enzymes, emphasizing their specificity in enzymatic reactions, notably the incorporation of polyunsaturated fatty acids (PUFAs) such as arachidonic acid and docosahexaenoic acid (DHA) into phospholipids. The paper sheds light on the intricate involvement of these enzymes in various diseases, including obesity, insulin resistance, and cancer. To underscore the relevance of these enzymes in cancer processes, a bioinformatics analysis was conducted. The expression levels of the described enzymes were correlated with the overall survival of patients across 33 different types of cancer using the GEPIA portal. This review further explores the potential therapeutic implications of inhibiting these enzymes in the treatment of metabolic diseases and cancer. By elucidating the intricate enzymatic pathways involved in lipid synthesis and their impact on various pathological conditions, this paper contributes to a comprehensive understanding of these processes and their potential as therapeutic targets.
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Affiliation(s)
- Jan Korbecki
- Department of Anatomy and Histology, Collegium Medicum, University of Zielona Góra, Zyty 28, 65-046 Zielona Góra, Poland;
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University in Szczecin, Powstańców Wlkp. 72, 70-111 Szczecin, Poland; (M.B.); (D.C.)
| | - Mateusz Bosiacki
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University in Szczecin, Powstańców Wlkp. 72, 70-111 Szczecin, Poland; (M.B.); (D.C.)
| | - Maciej Pilarczyk
- Department of Nervous System Diseases, Neurosurgery Center University Hospital in Zielona Góra, Collegium Medicum, University of Zielona Gora, 65-417 Zielona Góra, Poland; (M.P.); (P.J.)
| | - Magdalena Gąssowska-Dobrowolska
- Department of Cellular Signalling, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego 5, 02-106 Warsaw, Poland;
| | - Paweł Jarmużek
- Department of Nervous System Diseases, Neurosurgery Center University Hospital in Zielona Góra, Collegium Medicum, University of Zielona Gora, 65-417 Zielona Góra, Poland; (M.P.); (P.J.)
| | | | - Justyna Kulik-Sajewicz
- Department of Conservative Dentistry and Endodontics, Pomeranian Medical University in Szczecin, Powstańców Wlkp. 72, 70-111 Szczecin, Poland;
| | - Dariusz Chlubek
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University in Szczecin, Powstańców Wlkp. 72, 70-111 Szczecin, Poland; (M.B.); (D.C.)
| | - Irena Baranowska-Bosiacka
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University in Szczecin, Powstańców Wlkp. 72, 70-111 Szczecin, Poland; (M.B.); (D.C.)
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Valentine WJ, Shimizu T, Shindou H. Lysophospholipid acyltransferases orchestrate the compositional diversity of phospholipids. Biochimie 2023; 215:24-33. [PMID: 37611890 DOI: 10.1016/j.biochi.2023.08.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 08/14/2023] [Accepted: 08/19/2023] [Indexed: 08/25/2023]
Abstract
Lysophospholipid acyltransferases (LPLATs), in concert with glycerol-3-phosphate acyltransferases (GPATs) and phospholipase A1/2s, orchestrate the compositional diversity of the fatty chains in membrane phospholipids. Fourteen LPLAT enzymes which come from two distinct families, AGPAT and MBOAT, have been identified, and in this mini-review we provide an overview of their roles in de novo and remodeling pathways of membrane phospholipid biosynthesis. Recently new nomenclature for LPLATs has been introduced (LPLATx, where x is a number 1-14), and we also give an overview of key biological functions that have been discovered for LPLAT1-14, revealed primarily through studies of LPLAT-gene-deficient mice as well as by linkages to various human diseases.
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Affiliation(s)
- William J Valentine
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Tokyo, 187-8502, Japan.
| | - Takao Shimizu
- Department of Lipid Signaling, National Center for Global Health and Medicine (NCGM), Shinjuku-ku, Tokyo, 162-8655, Japan; Institute of Microbial Chemistry, Shinagawa-ku, Tokyo, 141-0021, Japan
| | - Hideo Shindou
- Department of Lipid Life Science, National Center for Global Health and Medicine (NCGM), Shinjuku-ku, Tokyo, 162-8655, Japan; Department of Lipid Medical Science, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan.
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3
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Krieger AC, Macias LA, Goodman JC, Brodbelt JS, Eberlin LS. Mass Spectrometry Imaging Reveals Abnormalities in Cardiolipin Composition and Distribution in Astrocytoma Tumor Tissues. Cancers (Basel) 2023; 15:2842. [PMID: 37345179 PMCID: PMC10216144 DOI: 10.3390/cancers15102842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 04/25/2023] [Accepted: 05/02/2023] [Indexed: 06/23/2023] Open
Abstract
Cardiolipin (CL) is a mitochondrial lipid with diverse roles in cellular respiration, signaling, and organelle membrane structure. CL content and composition are essential for proper mitochondrial function. Deranged mitochondrial energy production and signaling are key components of glial cell cancers and altered CL molecular species have been observed in mouse brain glial cell xenograft tumors. The objective of this study was to describe CL structural diversity trends in human astrocytoma tumors of varying grades and correlate these trends with histological regions within the heterogeneous astrocytoma microenvironment. To this aim, we applied desorption electrospray ionization coupled with high field asymmetric ion mobility mass spectrometry (DESI-FAIMS-MS) to map CL molecular species in human normal cortex (N = 29), lower-grade astrocytoma (N = 19), and glioblastoma (N = 28) tissues. With this platform, we detected 46 CL species and 12 monolysocardiolipin species from normal cortex samples. CL profiles detected from glioblastoma tissues lacked diversity and abundance of longer chain polyunsaturated fatty acid containing CL species when compared to CL detected from normal and lower-grade tumors. CL profiles correlated with trends in tumor viability and tumor infiltration. Structural characterization of the CL species by tandem MS experiments revealed differences in fatty acid and double bond isomer composition among astrocytoma tissues compared with normal cortex and glioblastoma tissues. The GlioVis platform was used to analyze astrocytoma gene expression data from the CGGA dataset. Decreased expression of several mitochondrial respiratory enzyme encoding-genes was observed for higher-grade versus lower-grade tumors, however no significant difference was observed for cardiolipin synthesis enzyme CRLS1.
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Affiliation(s)
- Anna C. Krieger
- Department of Chemistry, The University of Texas at Austin, Austin, TX 78712, USA
| | - Luis A. Macias
- Department of Chemistry, The University of Texas at Austin, Austin, TX 78712, USA
| | - J. Clay Goodman
- Departments of Pathology & Immunology and Neurology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jennifer S. Brodbelt
- Department of Chemistry, The University of Texas at Austin, Austin, TX 78712, USA
| | - Livia S. Eberlin
- Department of Chemistry, The University of Texas at Austin, Austin, TX 78712, USA
- Department of Surgery, Baylor College of Medicine, Houston, TX 77030, USA
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4
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O’Neill KC, Liapis E, Harris BT, Perlin DS, Carter CL. Mass spectrometry imaging discriminates glioblastoma tumor cell subpopulations and different microvascular formations based on their lipid profiles. Sci Rep 2022; 12:17069. [PMID: 36224354 PMCID: PMC9556690 DOI: 10.1038/s41598-022-22093-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 10/10/2022] [Indexed: 12/30/2022] Open
Abstract
Glioblastoma is a prevalent malignant brain tumor and despite clinical intervention, tumor recurrence is frequent and usually fatal. Genomic investigations have provided a greater understanding of molecular heterogeneity in glioblastoma, yet there are still no curative treatments, and the prognosis has remained unchanged. The aggressive nature of glioblastoma is attributed to the heterogeneity in tumor cell subpopulations and aberrant microvascular proliferation. Ganglioside-directed immunotherapy and membrane lipid therapy have shown efficacy in the treatment of glioblastoma. To truly harness these novel therapeutics and develop a regimen that improves clinical outcome, a greater understanding of the altered lipidomic profiles within the glioblastoma tumor microenvironment is urgently needed. In this work, high resolution mass spectrometry imaging was utilized to investigate lipid heterogeneity in human glioblastoma samples. Data presented offers the first insight into the histology-specific accumulation of lipids involved in cell metabolism and signaling. Cardiolipins, phosphatidylinositol, ceramide-1-phosphate, and gangliosides, including the glioblastoma stem cell marker, GD3, were shown to differentially accumulate in tumor and endothelial cell subpopulations. Conversely, a reduction in sphingomyelins and sulfatides were detected in tumor cell regions. Cellular accumulation for each lipid class was dependent upon their fatty acid residue composition, highlighting the importance of understanding lipid structure-function relationships. Discriminating ions were identified and correlated to histopathology and Ki67 proliferation index. These results identified multiple lipids within the glioblastoma microenvironment that warrant further investigation for the development of predictive biomarkers and lipid-based therapeutics.
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Affiliation(s)
- Kelly C. O’Neill
- grid.429392.70000 0004 6010 5947Center for Discovery and Innovation, Hackensack Meridian Health, 111 Ideation Way, Nutley, NJ 07110 USA
| | - Evangelos Liapis
- grid.429392.70000 0004 6010 5947Center for Discovery and Innovation, Hackensack Meridian Health, 111 Ideation Way, Nutley, NJ 07110 USA
| | - Brent T. Harris
- grid.411667.30000 0001 2186 0438Departments of Neurology and Pathology, Georgetown University Medical Center, Washington, D.C. 20007 USA
| | - David S. Perlin
- grid.429392.70000 0004 6010 5947Center for Discovery and Innovation, Hackensack Meridian Health, 111 Ideation Way, Nutley, NJ 07110 USA ,grid.429392.70000 0004 6010 5947Department of Medical Sciences, Hackensack Meridian School of Medicine, Nutley, NJ 07110 USA
| | - Claire L. Carter
- grid.429392.70000 0004 6010 5947Center for Discovery and Innovation, Hackensack Meridian Health, 111 Ideation Way, Nutley, NJ 07110 USA ,grid.429392.70000 0004 6010 5947Department of Pathology, Hackensack Meridian School of Medicine, Nutley, NJ 07110 USA
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5
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Zhang J, Shi Y. In Search of the Holy Grail: Toward a Unified Hypothesis on Mitochondrial Dysfunction in Age-Related Diseases. Cells 2022; 11:cells11121906. [PMID: 35741033 PMCID: PMC9221202 DOI: 10.3390/cells11121906] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 06/08/2022] [Accepted: 06/10/2022] [Indexed: 12/15/2022] Open
Abstract
Cardiolipin (CL) is a mitochondrial signature phospholipid that plays a pivotal role in mitochondrial dynamics, membrane structure, oxidative phosphorylation, mtDNA bioenergetics, and mitophagy. The depletion or abnormal acyl composition of CL causes mitochondrial dysfunction, which is implicated in the pathogenesis of aging and age-related disorders. However, the molecular mechanisms by which mitochondrial dysfunction causes age-related diseases remain poorly understood. Recent development in the field has identified acyl-CoA:lysocardiolipin acyltransferase 1 (ALCAT1), an acyltransferase upregulated by oxidative stress, as a key enzyme that promotes mitochondrial dysfunction in age-related diseases. ALCAT1 catalyzes CL remodeling with very-long-chain polyunsaturated fatty acids, such as docosahexaenoic acid (DHA). Enrichment of DHA renders CL highly sensitive to oxidative damage by reactive oxygen species (ROS). Oxidized CL becomes a new source of ROS in the form of lipid peroxides, leading to a vicious cycle of oxidative stress, CL depletion, and mitochondrial dysfunction. Consequently, ablation or the pharmacological inhibition of ALCAT1 have been shown to mitigate obesity, type 2 diabetes, heart failure, cardiomyopathy, fatty liver diseases, neurodegenerative diseases, and cancer. The findings suggest that age-related disorders are one disease (aging) manifested by different mitochondrion-sensitive tissues, and therefore should be treated as one disease. This review will discuss a unified hypothesis on CL remodeling by ALCAT1 as the common denominator of mitochondrial dysfunction, linking mitochondrial dysfunction to the development of age-related diseases.
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Affiliation(s)
| | - Yuguang Shi
- Correspondence: ; Tel.: +1-210-450-1363; Fax: +1-210-562-6150
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Valentine WJ, Yanagida K, Kawana H, Kono N, Noda NN, Aoki J, Shindou H. Update and nomenclature proposal for mammalian lysophospholipid acyltransferases which create membrane phospholipid diversity. J Biol Chem 2021; 298:101470. [PMID: 34890643 PMCID: PMC8753187 DOI: 10.1016/j.jbc.2021.101470] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 11/23/2021] [Indexed: 12/13/2022] Open
Abstract
The diversity of glycerophospholipid species in cellular membranes is immense and affects various biological functions. Glycerol-3-phosphate acyltransferases (GPATs) and lysophospholipid acyltransferases (LPLATs), in concert with phospholipase A1/2s enzymes, contribute to this diversity via selective esterification of fatty acyl chains at the sn-1 or sn-2 positions of membrane phospholipids. These enzymes are conserved across all kingdoms, and in mammals four GPATs of the 1-acylglycerol-3-phosphate O-acyltransferase (AGPAT) family and at least 14 LPLATs, either of the AGPAT or the membrane-bound O-acyltransferase (MBOAT) families, have been identified. Here we provide an overview of the biochemical and biological activities of these mammalian enzymes, including their predicted structures, involvements in human diseases, and essential physiological roles as revealed by gene-deficient mice. Recently, the nomenclature used to refer to these enzymes has generated some confusion due to the use of multiple names to refer to the same enzyme and instances of the same name being used to refer to completely different enzymes. Thus, this review proposes a more uniform LPLAT enzyme nomenclature, as well as providing an update of recent advances made in the study of LPLATs, continuing from our JBC mini review in 2009.
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Affiliation(s)
- William J Valentine
- Department of Lipid Signaling, National Center for Global Health and Medicine (NCGM), Shinjuku-ku, Tokyo 162-8655, Japan; Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Tokyo, 187-8502, Japan
| | - Keisuke Yanagida
- Department of Lipid Signaling, National Center for Global Health and Medicine (NCGM), Shinjuku-ku, Tokyo 162-8655, Japan
| | - Hiroki Kawana
- Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Nozomu Kono
- Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Nobuo N Noda
- Institute of Microbial Chemistry (BIKAKEN), Microbial Chemistry Research Foundation, Tokyo 141-0021, Japan
| | - Junken Aoki
- Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hideo Shindou
- Department of Lipid Signaling, National Center for Global Health and Medicine (NCGM), Shinjuku-ku, Tokyo 162-8655, Japan; Department of Lipid Medical Science, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
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7
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Role of Lysocardiolipin Acyltransferase in Cigarette Smoke-Induced Lung Epithelial Cell Mitochondrial ROS, Mitochondrial Dynamics, and Apoptosis. Cell Biochem Biophys 2021; 80:203-216. [PMID: 34724158 DOI: 10.1007/s12013-021-01043-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/20/2021] [Indexed: 02/07/2023]
Abstract
Cigarette smoke is the primary cause of Chronic Obstructive Pulmonary Disorder (COPD). Cigarette smoke extract (CSE)-induced oxidative damage of the lungs results in mitochondrial dysfunction and apoptosis of epithelium. Mitochondrial cardiolipin (CL) present in the inner mitochondrial membrane plays an important role in mitochondrial function, wherein its fatty acid composition is regulated by lysocardiolipin acyltransferase (LYCAT). In this study, we investigated the role of LYCAT expression and activity in mitochondrial oxidative stress, mitochondrial dynamics, and lung epithelial cell apoptosis. LYCAT expression was increased in human lung specimens from smokers, and cigarette smoke-exposed-mouse lung tissues. Cigarette smoke extract (CSE) increased LYCAT mRNA levels and protein expression, modulated cardiolipin fatty acid composition, and enhanced mitochondrial fission in the bronchial epithelial cell line, BEAS-2B in vitro. Inhibition of LYCAT activity with a peptide mimetic, attenuated CSE-mediated mitochondrial (mt) reactive oxygen species (ROS), mitochondrial fragmentation, and apoptosis, while MitoTEMPO attenuated CSE-induced MitoROS, mitochondrial fission and apoptosis of BEAS-2B cells. Collectively, these findings suggest that increased LYCAT expression promotes MitoROS, mitochondrial dynamics and apoptosis of lung epithelial cells. Given the key role of LYCAT in mitochondrial cardiolipin remodeling and function, strategies aimed at inhibiting LYCAT activity and ROS may offer an innovative approach to minimize lung inflammation caused by cigarette smoke.
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Mitchell JM, Flight RM, Moseley HNB. Untargeted Lipidomics of Non-Small Cell Lung Carcinoma Demonstrates Differentially Abundant Lipid Classes in Cancer vs. Non-Cancer Tissue. Metabolites 2021; 11:740. [PMID: 34822397 PMCID: PMC8622625 DOI: 10.3390/metabo11110740] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 10/24/2021] [Accepted: 10/25/2021] [Indexed: 01/25/2023] Open
Abstract
Lung cancer remains the leading cause of cancer death worldwide and non-small cell lung carcinoma (NSCLC) represents 85% of newly diagnosed lung cancers. In this study, we utilized our untargeted assignment tool Small Molecule Isotope Resolved Formula Enumerator (SMIRFE) and ultra-high-resolution Fourier transform mass spectrometry to examine lipid profile differences between paired cancerous and non-cancerous lung tissue samples from 86 patients with suspected stage I or IIA primary NSCLC. Correlation and co-occurrence analysis revealed significant lipid profile differences between cancer and non-cancer samples. Further analysis of machine-learned lipid categories for the differentially abundant molecular formulas identified a high abundance sterol, high abundance and high m/z sphingolipid, and low abundance glycerophospholipid metabolic phenotype across the NSCLC samples. At the class level, higher abundances of sterol esters and lower abundances of cardiolipins were observed suggesting altered stearoyl-CoA desaturase 1 (SCD1) or acetyl-CoA acetyltransferase (ACAT1) activity and altered human cardiolipin synthase 1 or lysocardiolipin acyltransferase activity respectively, the latter of which is known to confer apoptotic resistance. The presence of a shared metabolic phenotype across a variety of genetically distinct NSCLC subtypes suggests that this phenotype is necessary for NSCLC development and may result from multiple distinct genetic lesions. Thus, targeting the shared affected pathways may be beneficial for a variety of genetically distinct NSCLC subtypes.
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Affiliation(s)
- Joshua M. Mitchell
- Department of Molecular & Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA;
- Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA;
- Resource Center for Stable Isotope Resolved Metabolomics, University of Kentucky, Lexington, KY 40536, USA
| | - Robert M. Flight
- Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA;
- Resource Center for Stable Isotope Resolved Metabolomics, University of Kentucky, Lexington, KY 40536, USA
| | - Hunter N. B. Moseley
- Department of Molecular & Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA;
- Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA;
- Resource Center for Stable Isotope Resolved Metabolomics, University of Kentucky, Lexington, KY 40536, USA
- Institute for Biomedical Informatics, University of Kentucky, Lexington, KY 40536, USA
- Department of Toxicology and Cancer Biology, University of Kentucky, Lexington, KY 40536, USA
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9
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Cortactin Modulates Lung Endothelial Apoptosis Induced by Cigarette Smoke. Cells 2021; 10:cells10112869. [PMID: 34831092 PMCID: PMC8616125 DOI: 10.3390/cells10112869] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 10/19/2021] [Accepted: 10/20/2021] [Indexed: 12/19/2022] Open
Abstract
Cigarette smoke (CS) is the primary cause of Chronic Obstructive Pulmonary Disease (COPD), and an important pathophysiologic event in COPD is CS-induced apoptosis in lung endothelial cells (EC). Cortactin (CTTN) is a cytoskeletal actin-binding regulatory protein with modulation by Src-mediated tyrosine phosphorylation. Based upon data demonstrating reduced CTTN mRNA levels in the lungs of smokers compared to non-smokers, we hypothesized a functional role for CTTN in CS-induced mitochondrial ROS generation and apoptosis in lung EC. Exposure of cultured human lung EC to CS condensate (CSC) led to the rearrangement of the actin cytoskeleton and increased CTTN tyrosine phosphorylation (within hours). Exposure to CS significantly increased EC mitochondrial ROS generation and EC apoptosis. The functional role of CTTN in these CSC-induced EC responses was explored using cortactin siRNA to reduce its expression, and by using a blocking peptide for the CTTN SH3 domain, which is critical to cytoskeletal interactions. CTTN siRNA or blockade of its SH3 domain resulted in significantly increased EC mitochondrial ROS and apoptosis and augmented CSC-induced effects. Exposure of lung EC to e-cigarette condensate demonstrated similar results, with CTTN siRNA or SH3 domain blocking peptide increasing lung EC apoptosis. These data demonstrate a novel role for CTTN in modulating lung EC apoptosis induced by CS or e-cigarettes potentially providing new insights into COPD pathogenesis.
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Brindley DN. Viswanathan Natarajan: A Giant in Lipid Research and Pulmonary Disease and a True Gentleman. Cell Biochem Biophys 2021; 79:429-432. [PMID: 34251599 PMCID: PMC8274259 DOI: 10.1007/s12013-021-01018-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/22/2021] [Indexed: 11/04/2022]
Abstract
This article is intended to recognize and the life time contribution that Dr. Viswanathan Natarajan has made to the advancement of lipid metabolism and lipid signaling. In particular, his major contributions in the last three decades have been made in understanding how lipids such as phosphatidic acid, lysophosphatidic acid, sphingosine 1-phosphate and cardiolipin contribute to healthy lung functions and to a variety of lung pathologies. We celebrate a truly remarkable career and look forward to seeing even more remarkable discoveries.
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Affiliation(s)
- David N Brindley
- Department of Biochemistry, Cancer Research Institute of Northern Alberta, 357 Heritage Medical Research Centre, University of Alberta, Edmonton, T6G 2S2, AB, Canada.
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11
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Abstract
An overview of Prof. Viswanathan Natarajan's journey in academia as a mentor, teacher, and lipid scientist for nearly 50 years is presented. As a graduate student, Dr. Natarajan interrogated biosynthesis and catabolism of phospholipids in the developing brain; however, in the last five decades, he has been investigating the role of sphingolipids and sphingolipid-metabolizing enzymes in pulmonary endothelial cells, epithelial cells, and fibroblasts under normal conditions and during various lung pathologies such as sepsis, asthma, pulmonary hypertension, idiopathic pulmonary fibrosis, bronchopulmonary dysplasia, and lung cancer. His recent work on sphingosine-1-phosphate and lysophosphatidic acid metabolism in pre-clinical animal models has identified small molecule inhibitors in the signaling pathways that could have therapeutic potential in ameliorating pulmonary fibrosis, hypoxia-induced pulmonary hypertension, lung cancer, and bronchopulmonary dysplasia. Future research in bioactive lipids in combination with OMICS should unravel the importance of various lipid mediators as modulators of cell function under normal and pathological conditions.
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Affiliation(s)
- Viswanathan Natarajan
- Departments of Pharmacology & Regenerative Medicine and Medicine, University of Illinois, Chicago, IL 60612 USA
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