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Mu Y, Wang Z, Song L, Ma K, Chen Y, Li P, Yan Z. Modulating lipid bilayer permeability and structure: Impact of hydrophobic chain length, C-3 hydroxyl group, and double bond in sphingosine. J Colloid Interface Sci 2024; 674:513-526. [PMID: 38943912 DOI: 10.1016/j.jcis.2024.06.171] [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: 02/19/2024] [Revised: 06/14/2024] [Accepted: 06/23/2024] [Indexed: 07/01/2024]
Abstract
Sphingosine, an amphiphilic molecule, plays a pivotal role as the core structure of sphingolipids, essential constituents of cell membranes. Its unique capability to enhance the permeability of lipid membranes profoundly influences crucial life processes. The molecular structure of sphingosine dictates its mode of entry into lipid bilayers and governs its interactions with lipids, thereby determining membrane permeability. However, the incomplete elucidation of the relationship between the molecular structure of sphingosine and the permeability of lipid membranes persists due to challenges associated with synthesizing sphingosine molecules. A series of sphingosine-derived molecules, featuring diverse hydrophobic chain lengths and distinct headgroup structure, were meticulously designed and successfully synthesized. These molecules were employed to investigate the permeability of large unilamellar vesicles, functioning as model lipid bilayers. With a decrease in the hydrophobic chain length of sphingosine from C15 to C11, the transient leakage ratio of vesicle contents escalated from ∼ 13 % to ∼ 28 %. Although the presence of double bond did not exert a pronounced influence on transient leakage, it significantly affected the continuous leakage ratio. Conversely, modifying the chirality of the C-3 hydroxyl group gives the opposite result. Notably, methylation at the C-3 hydroxyl significantly elevates transient leakage while suppressing the continuous leakage ratio. Additionally, sphingosines that significantly affect vesicle permeability tend to have a more pronounced impact on cell viability. Throughout this leakage process, the charge state of sphingosine-derived molecule aggregates in the solution emerged as a pivotal factor influencing vesicle permeability. Fluorescence lifetime experiments further revealed discernible variations in the effect of sphingosine molecular structure on the mobility of hydrophobic regions within lipid bilayers. These observed distinctions emphasize the impact of molecular structure on intermolecular interactions, extending to the microscopic architecture of membranes, and underscore the significance of subtle alterations in molecular structure and their associated aggregation behaviors in governing membrane permeability.
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Affiliation(s)
- Yonghang Mu
- State Key Laboratory of Heavy Oil Processing, College of Chemistry and Chemical Engineering, China University of Petroleum, Qingdao 266580, China
| | - Zi Wang
- State Key Laboratory of Heavy Oil Processing, College of Chemistry and Chemical Engineering, China University of Petroleum, Qingdao 266580, China.
| | - Linhua Song
- State Key Laboratory of Heavy Oil Processing, College of Chemistry and Chemical Engineering, China University of Petroleum, Qingdao 266580, China
| | - Kun Ma
- ISIS Facility, Rutherford Appleton Laboratory, STFC, Chilton, Didcot, Oxon OX11 0QX, UK
| | - Yao Chen
- ISIS Facility, Rutherford Appleton Laboratory, STFC, Chilton, Didcot, Oxon OX11 0QX, UK
| | - Peixun Li
- ISIS Facility, Rutherford Appleton Laboratory, STFC, Chilton, Didcot, Oxon OX11 0QX, UK
| | - Zifeng Yan
- State Key Laboratory of Heavy Oil Processing, College of Chemistry and Chemical Engineering, China University of Petroleum, Qingdao 266580, China.
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2
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Wheeler S, Bhardwaj M, Kenyon V, Ferraz MJ, Aerts JMFG, Sillence DJ. Mitochondrial dysfunction in NPC1-deficiency is not rescued by drugs targeting the glucosylceramidase GBA2 and the cholesterol-binding proteins TSPO and StARD1. FEBS Lett 2024; 598:477-484. [PMID: 38302739 DOI: 10.1002/1873-3468.14802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 12/04/2023] [Accepted: 12/14/2023] [Indexed: 02/03/2024]
Abstract
Niemann-Pick type C disease (NPCD) is a rare neurodegenerative disorder most commonly caused by mutations in the lysosomal protein Niemann-Pick C1 (NPC1), which is implicated in cholesterol export. Mitochondrial insufficiency forms a significant feature of the pathology of this disease, yet studies attempting to address this are rare. The working hypothesis is that mitochondria become overloaded with cholesterol which renders them dysfunctional. We examined two potential protein targets-translocator protein (TSPO) and steroidogenic acute regulatory protein D1 (StARD1)-which are implicated in cholesterol transport to mitochondria, in addition to glucocerbrosidase 2 (GBA2), the target of miglustat, which is currently the only approved treatment for NPCD. However, inhibiting these proteins did not correct the mitochondrial defect in NPC1-deficient cells.
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Affiliation(s)
- Simon Wheeler
- Leicester School of Pharmacy, De Montfort University, Leicester, UK
| | | | | | - Maria J Ferraz
- Leiden Institute of Chemistry, Leiden University, The Netherlands
| | | | - Dan J Sillence
- Leicester School of Pharmacy, De Montfort University, Leicester, UK
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3
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Preau S, Vodovar D, Jung B, Lancel S, Zafrani L, Flatres A, Oualha M, Voiriot G, Jouan Y, Joffre J, Huel F, De Prost N, Silva S, Azabou E, Radermacher P. Energetic dysfunction in sepsis: a narrative review. Ann Intensive Care 2021; 11:104. [PMID: 34216304 PMCID: PMC8254847 DOI: 10.1186/s13613-021-00893-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Accepted: 06/24/2021] [Indexed: 02/07/2023] Open
Abstract
Background Growing evidence associates organ dysfunction(s) with impaired metabolism in sepsis. Recent research has increased our understanding of the role of substrate utilization and mitochondrial dysfunction in the pathophysiology of sepsis-related organ dysfunction. The purpose of this review is to present this evidence as a coherent whole and to highlight future research directions. Main text Sepsis is characterized by systemic and organ-specific changes in metabolism. Alterations of oxygen consumption, increased levels of circulating substrates, impaired glucose and lipid oxidation, and mitochondrial dysfunction are all associated with organ dysfunction and poor outcomes in both animal models and patients. The pathophysiological relevance of bioenergetics and metabolism in the specific examples of sepsis-related immunodeficiency, cerebral dysfunction, cardiomyopathy, acute kidney injury and diaphragmatic failure is also described. Conclusions Recent understandings in substrate utilization and mitochondrial dysfunction may pave the way for new diagnostic and therapeutic approaches. These findings could help physicians to identify distinct subgroups of sepsis and to develop personalized treatment strategies. Implications for their use as bioenergetic targets to identify metabolism- and mitochondria-targeted treatments need to be evaluated in future studies. Supplementary Information The online version contains supplementary material available at 10.1186/s13613-021-00893-7.
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Affiliation(s)
- Sebastien Preau
- U1167 - RID-AGE - Facteurs de Risque et Déterminants Moléculaires des Maladies Liées au Vieillissement, University Lille, Inserm, CHU Lille, Institut Pasteur de Lille, F-59000, Lille, France.
| | - Dominique Vodovar
- Centre AntiPoison de Paris, Hôpital Fernand Widal, APHP, 75010, Paris, France.,Faculté de pharmacie, UMRS 1144, 75006, Paris, France.,Université de Paris, UFR de Médecine, 75010, Paris, France
| | - Boris Jung
- Medical Intensive Care Unit, Lapeyronie Teaching Hospital, Montpellier University Hospital and PhyMedExp, University of Montpellier, Montpellier, France
| | - Steve Lancel
- U1167 - RID-AGE - Facteurs de Risque et Déterminants Moléculaires des Maladies Liées au Vieillissement, University Lille, Inserm, CHU Lille, Institut Pasteur de Lille, F-59000, Lille, France
| | - Lara Zafrani
- Médecine Intensive Réanimation, Hôpital Saint-Louis, AP-HP, Université de Paris, Paris, France.,INSERM UMR 976, Hôpital Saint Louis, Université de Paris, Paris, France
| | | | - Mehdi Oualha
- Pediatric Intensive Care Unit, Necker Hospital, APHP, Centre - Paris University, Paris, France
| | - Guillaume Voiriot
- Service de Médecine Intensive Réanimation, Sorbonne Université, Assistance Publique - Hôpitaux de Paris, Hôpital Tenon, Paris, France
| | - Youenn Jouan
- Service de Médecine Intensive Réanimation, CHRU Tours, Tours, France.,Faculté de Médecine de Tours, INSERM U1100 Centre d'Etudes des Pathologies Respiratoires, Tours, France
| | - Jeremie Joffre
- Department of Anesthesia and Perioperative Care, University of California, San Francisco, CA, 94143, USA
| | - Fabrice Huel
- Réanimation médico-chirurgicale, Université de Paris, Assistance Publique - Hôpitaux de Paris, Hôpital Louis Mourier, Paris, France
| | - Nicolas De Prost
- Service de Réanimation Médicale, Hôpital Henri Mondor, Assistance Publique-Hôpitaux de Paris, Cedex 94010, Créteil, France
| | - Stein Silva
- Réanimation URM CHU Purpan, Cedex 31300, Toulouse, France.,Toulouse NeuroImaging Center INSERM1214, Cedex 31300, Toulouse, France
| | - Eric Azabou
- Clinical Neurophysiology and Neuromodulation Unit, Departments of Physiology and Critical Care Medicine, Raymond Poincaré Hospital, AP-HP, Inserm UMR 1173, Infection and Inflammation (2I), University of Versailles (UVSQ), Paris-Saclay University, Paris, France
| | - Peter Radermacher
- Institut für Anästhesiologische Pathophysiologie und Verfahrensentwicklung, Universitätsklinikum, Ulm, Germany
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4
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Truman JP, Ruiz CF, Trayssac M, Mao C, Hannun YA, Obeid LM. Sphingosine kinase 1 downregulation is required for adaptation to serine deprivation. FASEB J 2021; 35:e21284. [PMID: 33484475 DOI: 10.1096/fj.202001814rr] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 11/25/2020] [Accepted: 12/01/2020] [Indexed: 01/21/2023]
Abstract
It has been well-established that cancer cells often display altered metabolic profiles, and recent work has concentrated on how cancer cells adapt to serine removal. Serine can be either taken exogenously or synthesized from glucose, and its regulation forms an important mechanism for nutrient integration. One of the several important metabolic roles for serine is in the generation of bioactive sphingolipids since it is the main substrate for serine palmitoyltransferase, the initial and rate-limiting enzyme in the synthesis of sphingolipids. Previously, serine deprivation has been connected to the action of the tumor suppressor p53, and we have previously published on a role for p53 regulating sphingosine kinase 1 (SK1), an enzyme that phosphorylates sphingosine to form sphingosine-1-phosphate (S1P). SK1 is a key enzyme in sphingolipid synthesis that functions in pro-survival and tumor-promoting pathways and whose expression is also often elevated in cancers. Here we show that SK1 was degraded during serine starvation in a time and dose-dependent manner, which led to sphingosine accumulation. This was independent of effects on p53 but required the action of the proteasome. Furthermore, we show that overexpression of SK1, to compensate for SK1 loss, was detrimental to cell growth under conditions of serine starvation, demonstrating that the suppression of SK1 under these conditions is adaptive. Mitochondrial oxygen consumption decreased in response to SK1 degradation, and this was accompanied by an increase in intracellular reactive oxygen species (ROS). Suppression of ROS with N-acteylcysteine resulted in suppression of the metabolic adaptations and in decreased cell growth under serine deprivation. The effects of SK1 suppression on ROS were mimicked by D-erythro-sphingosine, whereas S1P was ineffective, suggesting that the effects of loss of SK1 were due to the accumulation of its substrate sphingosine. This study reveals a new mechanism for regulating SK1 levels and a link of SK1 to serine starvation as well as mitochondrial function.
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Affiliation(s)
- Jean-Philip Truman
- Department of Medicine, Stony Brook University, Stony Brook, NY, USA.,The Stony Brook Cancer Center, Stony Brook University, Stony Brook, NY, USA
| | - Christian F Ruiz
- Department of Genetics, School of Medicine, Yale University, New Haven, CT, USA
| | - Magali Trayssac
- Department of Medicine, Stony Brook University, Stony Brook, NY, USA.,The Stony Brook Cancer Center, Stony Brook University, Stony Brook, NY, USA
| | - Cungui Mao
- Department of Medicine, Stony Brook University, Stony Brook, NY, USA.,The Stony Brook Cancer Center, Stony Brook University, Stony Brook, NY, USA
| | - Yusuf A Hannun
- Department of Medicine, Stony Brook University, Stony Brook, NY, USA.,The Stony Brook Cancer Center, Stony Brook University, Stony Brook, NY, USA.,Department of Biochemistry, Stony Brook University, Stony Brook, NY, USA.,Department of Pathology, Stony Brook University, Stony Brook, NY, USA
| | - Lina M Obeid
- Department of Medicine, Stony Brook University, Stony Brook, NY, USA.,The Stony Brook Cancer Center, Stony Brook University, Stony Brook, NY, USA.,Northport Veterans Affairs Medical Center, Northport, NY, USA
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5
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Novgorodov SA, Riley CL, Yu J, Keffler JA, Clarke CJ, Van Laer AO, Baicu CF, Zile MR, Gudz TI. Lactosylceramide contributes to mitochondrial dysfunction in diabetes. J Lipid Res 2016; 57:546-62. [PMID: 26900161 PMCID: PMC4808764 DOI: 10.1194/jlr.m060061] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 02/16/2016] [Indexed: 02/02/2023] Open
Abstract
Sphingolipids have been implicated as key mediators of cell-stress responses and effectors of mitochondrial function. To investigate potential mechanisms underlying mitochondrial dysfunction, an important contributor to diabetic cardiomyopathy, we examined alterations of cardiac sphingolipid metabolism in a mouse with streptozotocin-induced type 1 diabetes. Diabetes increased expression of desaturase 1, (dihydro)ceramide synthase (CerS)2, serine palmitoyl transferase 1, and the rate of ceramide formation by mitochondria-resident CerSs, indicating an activation of ceramide biosynthesis. However, the lack of an increase in mitochondrial ceramide suggests concomitant upregulation of ceramide-metabolizing pathways. Elevated levels of lactosylceramide, one of the initial products in the formation of glycosphingolipids were accompanied with decreased respiration and calcium retention capacity (CRC) in mitochondria from diabetic heart tissue. In baseline mitochondria, lactosylceramide potently suppressed state 3 respiration and decreased CRC, suggesting lactosylceramide as the primary sphingolipid responsible for mitochondrial defects in diabetic hearts. Moreover, knocking down the neutral ceramidase (NCDase) resulted in an increase in lactosylceramide level, suggesting a crosstalk between glucosylceramide synthase- and NCDase-mediated ceramide utilization pathways. These data suggest the glycosphingolipid pathway of ceramide metabolism as a promising target to correct mitochondrial abnormalities associated with type 1 diabetes.
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Affiliation(s)
- Sergei A Novgorodov
- Departments of Neuroscience Medical University of South Carolina, Charleston, SC 29425
| | | | - Jin Yu
- Departments of Neuroscience Medical University of South Carolina, Charleston, SC 29425
| | - Jarryd A Keffler
- Departments of Neuroscience Medical University of South Carolina, Charleston, SC 29425
| | | | - An O Van Laer
- Ralph H. Johnson Veteran Affairs Medical Center, Charleston, SC 29401 Medicine, Medical University of South Carolina, Charleston, SC 29425
| | - Catalin F Baicu
- Ralph H. Johnson Veteran Affairs Medical Center, Charleston, SC 29401 Medicine, Medical University of South Carolina, Charleston, SC 29425
| | - Michael R Zile
- Ralph H. Johnson Veteran Affairs Medical Center, Charleston, SC 29401 Medicine, Medical University of South Carolina, Charleston, SC 29425
| | - Tatyana I Gudz
- Departments of Neuroscience Medical University of South Carolina, Charleston, SC 29425 Ralph H. Johnson Veteran Affairs Medical Center, Charleston, SC 29401
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6
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Clay HB, Parl AK, Mitchell SL, Singh L, Bell LN, Murdock DG. Altering the Mitochondrial Fatty Acid Synthesis (mtFASII) Pathway Modulates Cellular Metabolic States and Bioactive Lipid Profiles as Revealed by Metabolomic Profiling. PLoS One 2016; 11:e0151171. [PMID: 26963735 PMCID: PMC4786287 DOI: 10.1371/journal.pone.0151171] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 02/24/2016] [Indexed: 01/10/2023] Open
Abstract
Despite the presence of a cytosolic fatty acid synthesis pathway, mitochondria have retained their own means of creating fatty acids via the mitochondrial fatty acid synthesis (mtFASII) pathway. The reason for its conservation has not yet been elucidated. Therefore, to better understand the role of mtFASII in the cell, we used thin layer chromatography to characterize the contribution of the mtFASII pathway to the fatty acid composition of selected mitochondrial lipids. Next, we performed metabolomic analysis on HeLa cells in which the mtFASII pathway was either hypofunctional (through knockdown of mitochondrial acyl carrier protein, ACP) or hyperfunctional (through overexpression of mitochondrial enoyl-CoA reductase, MECR). Our results indicate that the mtFASII pathway contributes little to the fatty acid composition of mitochondrial lipid species examined. Additionally, loss of mtFASII function results in changes in biochemical pathways suggesting alterations in glucose utilization and redox state. Interestingly, levels of bioactive lipids, including lysophospholipids and sphingolipids, directly correlate with mtFASII function, indicating that mtFASII may be involved in the regulation of bioactive lipid levels. Regulation of bioactive lipid levels by mtFASII implicates the pathway as a mediator of intracellular signaling.
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Affiliation(s)
- Hayley B. Clay
- Center for Human Genetics Research, Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States of America
- Neuroscience Graduate Program, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Angelika K. Parl
- Center for Human Genetics Research, Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Sabrina L. Mitchell
- Center for Human Genetics Research, Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Larry Singh
- Center for Mitochondrial and Epigenomic Medicine, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Lauren N. Bell
- Metabolon, Incorporated, Durham, North Carolina, United States of America
| | - Deborah G. Murdock
- Center for Human Genetics Research, Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States of America
- * E-mail:
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7
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Teixeira V, Costa V. Unraveling the role of the Target of Rapamycin signaling in sphingolipid metabolism. Prog Lipid Res 2015; 61:109-33. [PMID: 26703187 DOI: 10.1016/j.plipres.2015.11.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 11/04/2015] [Accepted: 11/09/2015] [Indexed: 02/06/2023]
Abstract
Sphingolipids are important bioactive molecules that regulate basic aspects of cellular metabolism and physiology, including cell growth, adhesion, migration, senescence, apoptosis, endocytosis, and autophagy in yeast and higher eukaryotes. Since they have the ability to modulate the activation of several proteins and signaling pathways, variations in the relative levels of different sphingolipid species result in important changes in overall cellular functions and fate. Sphingolipid metabolism and their route of synthesis are highly conserved from yeast to mammalian cells. Studies using the budding yeast Saccharomyces cerevisiae have served in many ways to foster our understanding of sphingolipid dynamics and their role in the regulation of cellular processes. In the past decade, studies in S. cerevisiae have unraveled a functional association between the Target of Rapamycin (TOR) pathway and sphingolipids, showing that both TOR Complex 1 (TORC1) and TOR Complex 2 (TORC2) branches control temporal and spatial aspects of sphingolipid metabolism in response to physiological and environmental cues. In this review, we report recent findings in this emerging and exciting link between the TOR pathway and sphingolipids and implications in human health and disease.
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Affiliation(s)
- Vitor Teixeira
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; IBMC, Instituto de Biologia Molecular e Celular, Porto, Portugal; ICBAS, Instituto de Ciências Biomédicas Abel Salazar, Departamento de Biologia Molecular, Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Vítor Costa
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; IBMC, Instituto de Biologia Molecular e Celular, Porto, Portugal; ICBAS, Instituto de Ciências Biomédicas Abel Salazar, Departamento de Biologia Molecular, Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
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8
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Abstract
A hallmark of tissue injury in various models of ischemia/reperfusion (IR) is mitochondrial dysfunction and the release of mitochondrial proapoptotic proteins leading to cell death. Although IR-induced mitochondrial injury has been extensively studied and key mitochondrial functions affected by IR are chiefly characterized, the nature of the molecule that causes loss of mitochondrial integrity and function remains obscure. It has become increasingly clear that ceramide, a membrane sphingolipid and a key mediator of cell stress responses, could play a critical role in IR-induced mitochondrial damage. Emerging data point to excessive ceramide accumulation in tissue and, specifically, in mitochondria after IR. Exogenously added to isolated mitochondria, ceramide could mimic some of the mitochondrial dysfunctions occurring in IR. The recent identification and characterization of major enzymes in ceramide synthesis is expected to contribute to the understanding of molecular mechanisms of ceramide involvement in mitochondrial damage in IR. This review will examine the experimental evidence supporting the important role of ceramide in mitochondrial dysfunction in IR to highlight potential targets for pharmacological manipulation of ceramide levels.
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9
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Pavoine C, Pecker F. Sphingomyelinases: their regulation and roles in cardiovascular pathophysiology. Cardiovasc Res 2009; 82:175-83. [PMID: 19176603 DOI: 10.1093/cvr/cvp030] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Sphingomyelinases (SMases) hydrolyse sphingomyelin, releasing ceramide and creating a cascade of bioactive lipids. These lipids include sphingosine and sphingosine-1-phosphate, all of which have a specific signalling capacity. Sphingomyelinase activation occurs in different cardiovascular system cell types, namely cardiac myocytes, endothelial and vascular smooth muscle cells, mediating cell proliferation, cell death, and contraction of cardiac and vascular myocytes. Three main types of SMases contribute to cardiovascular physiology: the lysosomal and secreted acidic SMases (L- and S-ASMases, respectively) and the membrane neutral SMase (NSMase). These three enzymes have common activators, including ischaemia/reperfusion stress and proinflammatory cytokines, but they differ in their enzymatic properties and subcellular locations that determine the final effect of enzyme activation. This review focuses on the recent advances in the understanding of ASMase and NSMase pathways and their specific contribution to cardiovascular pathophysiology. Current knowledge indicates that the inhibitors of the different SMase types are potential tools for the treatment of cardiovascular diseases. Acid SMase inhibitors could be tools against post-ischaemia reperfusion injury and in the treatment of atherosclerosis. Neutral SMase inhibitors could be tools for the treatment of atherosclerosis, heart failure, and age-related decline in vasomotion. However, the design of bioavailable and more specific SMase-type inhibitors remains a challenge.
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10
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Jin ZQ, Karliner JS, Vessey DA. Ischaemic postconditioning protects isolated mouse hearts against ischaemia/reperfusion injury via sphingosine kinase isoform-1 activation. Cardiovasc Res 2008; 79:134-40. [PMID: 18334546 DOI: 10.1093/cvr/cvn065] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
AIMS Sphingosine-1-phosphate (S1P) plays a vital role in cytoskeletal rearrangement, development, and apoptosis. Sphingosine kinase-1 (SphK1), the key enzyme catalyzing the formation of S1P, mediates ischaemic preconditioning. Ischaemic postconditioning (POST) has been shown to protect hearts against ischaemia/reperfusion injury (IR). To date, no studies have examined the role of SphK1 in POST. METHODS AND RESULTS Wild-type (WT) and SphK1 null (KO) mouse hearts were subjected to IR (45 min of global ischaemia and 45 min of reperfusion) in a Langendorff apparatus. Left ventricular developed pressure (LVDP), maximum velocity of increase or decrease of LV pressure (+/-dP/dtmax), and LV end-diastolic pressure (LVEDP) were recorded. Infarction size was measured by 1% triphenyltetrazolium chloride staining. POST, consisting of 5 s of ischaemia and 5 s of reperfusion for three cycles after the index ischaemia, protected hearts against IR: recovery of LVDP and +/-dP/dtmax were elevated; LVEDP was decreased; infarction size (% of risk area) was reduced from 40 +/- 2% in the control group to 29 +/- 2% of the risk area in the POST group (P < 0.05, n = 4 per group). Phosphorylation of Akt and extracellular signal-regulated kinases detected by Western blotting was increased at 10 min of reperfusion. The protection induced by POST was abolished in KO hearts. Infarction size in KO hearts (57 +/- 5%) was not different from the KO control group (53 +/- 5% of risk area, n = 4, P = NS). CONCLUSIONS A short period of ischaemic POST protected WT mouse hearts against IR. The cardiac protection induced by POST was abrogated in SphK1-KO mouse hearts. Thus, SphK1 is critical for successful ischaemic POST.
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Affiliation(s)
- Zhu-Qiu Jin
- Cardiology Section, Veterans Affairs Medical Center, San Francisco, CA 94121, USA
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11
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Van Driessche N, Alexander H, Min J, Kuspa A, Alexander S, Shaulsky G. Global transcriptional responses to cisplatin in Dictyostelium discoideum identify potential drug targets. Proc Natl Acad Sci U S A 2007; 104:15406-11. [PMID: 17878305 PMCID: PMC2000517 DOI: 10.1073/pnas.0705996104] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Dictyostelium discoideum is a useful model for studying mechanisms of cisplatin drug sensitivity. Our previous findings, that mutations in sphingolipid metabolism genes confer cisplatin resistance in D. discoideum and in human cells, raised interest in the resistance mechanisms and their implications for cisplatin chemotherapy. Here we used expression microarrays to monitor physiological changes and to identify pathways that are affected by cisplatin treatment of D. discoideum. We found >400 genes whose regulation was altered by cisplatin treatment of wild-type cells, including groups of genes that participate in cell proliferation and in nucleotide and protein metabolism, showing that the cisplatin response is orderly and multifaceted. Transcriptional profiling of two isogenic cisplatin-resistant mutants, impaired in different sphingolipid metabolism steps, showed that the effect of cisplatin treatment was greater than the effect of the mutations, indicating that cisplatin resistance in the mutants is due to specific abilities to overcome the drug effects rather than to general drug insensitivity. Nevertheless, the mutants exhibited significantly different responses to cisplatin compared with the parent, and >200 genes accounted for that difference. Mutations in five cisplatin response genes (sgkB, csbA, acbA, smlA, and atg8) resulted in altered drug sensitivity, implicating novel pathways in cisplatin response. Our data illustrate how modeling complex cellular responses to drugs in genetically stable and tractable systems can uncover new targets with the potential for improving chemotherapy.
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Affiliation(s)
| | - Hannah Alexander
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211
| | - Junxia Min
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211
| | - Adam Kuspa
- Departments of *Molecular and Human Genetics and
- Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030; and
| | - Stephen Alexander
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211
- To whom correspondence may be addressed. E-mail: or
| | - Gad Shaulsky
- Departments of *Molecular and Human Genetics and
- To whom correspondence may be addressed. E-mail: or
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