1
|
Zhang T, Qian Y, Mo L, Dong X, Xue Q, Zheng N, Qi Y, Jiang Y. Chronic ethanol exposure induces cardiac fibroblast transdifferentiation via ceramide accumulation and oxidative stress. Toxicol Mech Methods 2024:1-12. [PMID: 39143746 DOI: 10.1080/15376516.2024.2388762] [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: 04/08/2024] [Revised: 07/10/2024] [Accepted: 07/31/2024] [Indexed: 08/16/2024]
Abstract
AIMS Excessive alcohol consumption is associated with cardiac dysfunction and the development of myocardial fibrosis. In this study, we aimed to investigate the direct impacts of ethanol on myocardial fibroblasts and elucidate the underlying mechanism responsible for chronic ethanol-induced myocardial fibrosis. METHODS Rat primary cardiac fibroblasts exposed to ethanol for 24 h and C57BL/6J mice fed on Lieber-DeCarli diet to establish an ethanol intoxication model in vitro and in vivo, respectively. Histological analyses, molecular biology techniques, and analytical chemistry methods were then conducted. RESULTS AND CONCLUSION In vivo and vitro experiments revealed that chronic ethanol exposure induced increased myocardial fibrosis and augmented the transdifferentiation of myocardial fibroblasts. Simultaneously, it elicited an upregulation in the production of long-chain and very-long-chain ceramides in cardiac fibroblasts. The excessive accumulation of ceramide leads to elevated levels of intracellular oxidative stress, culminating in the activation of TGF-β-SMAD3 signaling and the development of fibrosis. Intervention of these pathways with pharmacological inhibitors in vitro or in vivo inhibited fibrosis. In conclusion, ethanol increased ceramides and reactive oxygen species (ROS) in cardiac fibroblasts, resulting in the activation of TGF-β-SMAD3 signaling, transdifferentiation of fibroblasts, and myocardial fibrosis.
Collapse
Affiliation(s)
- Tianyi Zhang
- Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Yile Qian
- Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Lingjie Mo
- Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Xiaoru Dong
- Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Qiupeng Xue
- Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Nianchang Zheng
- Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Yanyu Qi
- School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Yan Jiang
- Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai, China
| |
Collapse
|
2
|
Wilkerson JL, Tatum SM, Holland WL, Summers SA. Ceramides are fuel gauges on the drive to cardiometabolic disease. Physiol Rev 2024; 104:1061-1119. [PMID: 38300524 DOI: 10.1152/physrev.00008.2023] [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: 02/14/2023] [Revised: 01/23/2024] [Accepted: 01/25/2024] [Indexed: 02/02/2024] Open
Abstract
Ceramides are signals of fatty acid excess that accumulate when a cell's energetic needs have been met and its nutrient storage has reached capacity. As these sphingolipids accrue, they alter the metabolism and survival of cells throughout the body including in the heart, liver, blood vessels, skeletal muscle, brain, and kidney. These ceramide actions elicit the tissue dysfunction that underlies cardiometabolic diseases such as diabetes, coronary artery disease, metabolic-associated steatohepatitis, and heart failure. Here, we review the biosynthesis and degradation pathways that maintain ceramide levels in normal physiology and discuss how the loss of ceramide homeostasis drives cardiometabolic pathologies. We highlight signaling nodes that sense small changes in ceramides and in turn reprogram cellular metabolism and stimulate apoptosis. Finally, we evaluate the emerging therapeutic utility of these unique lipids as biomarkers that forecast disease risk and as targets of ceramide-lowering interventions that ameliorate disease.
Collapse
Affiliation(s)
- Joseph L Wilkerson
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah, United States
| | - Sean M Tatum
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah, United States
| | - William L Holland
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah, United States
| | - Scott A Summers
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah, United States
| |
Collapse
|
3
|
Seal A, Hughes M, Wei F, Pugazhendhi AS, Ngo C, Ruiz J, Schwartzman JD, Coathup MJ. Sphingolipid-Induced Bone Regulation and Its Emerging Role in Dysfunction Due to Disease and Infection. Int J Mol Sci 2024; 25:3024. [PMID: 38474268 DOI: 10.3390/ijms25053024] [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: 02/09/2024] [Revised: 03/02/2024] [Accepted: 03/04/2024] [Indexed: 03/14/2024] Open
Abstract
The human skeleton is a metabolically active system that is constantly regenerating via the tightly regulated and highly coordinated processes of bone resorption and formation. Emerging evidence reveals fascinating new insights into the role of sphingolipids, including sphingomyelin, sphingosine, ceramide, and sphingosine-1-phosphate, in bone homeostasis. Sphingolipids are a major class of highly bioactive lipids able to activate distinct protein targets including, lipases, phosphatases, and kinases, thereby conferring distinct cellular functions beyond energy metabolism. Lipids are known to contribute to the progression of chronic inflammation, and notably, an increase in bone marrow adiposity parallel to elevated bone loss is observed in most pathological bone conditions, including aging, rheumatoid arthritis, osteoarthritis, and osteomyelitis. Of the numerous classes of lipids that form, sphingolipids are considered among the most deleterious. This review highlights the important primary role of sphingolipids in bone homeostasis and how dysregulation of these bioactive metabolites appears central to many chronic bone-related diseases. Further, their contribution to the invasion, virulence, and colonization of both viral and bacterial host cell infections is also discussed. Many unmet clinical needs remain, and data to date suggest the future use of sphingolipid-targeted therapy to regulate bone dysfunction due to a variety of diseases or infection are highly promising. However, deciphering the biochemical and molecular mechanisms of this diverse and extremely complex sphingolipidome, both in terms of bone health and disease, is considered the next frontier in the field.
Collapse
Affiliation(s)
- Anouska Seal
- Biionix Cluster, University of Central Florida, Orlando, FL 32827, USA
| | - Megan Hughes
- School of Biosciences, Cardiff University, Cardiff CF10 3AT, UK
| | - Fei Wei
- Biionix Cluster, University of Central Florida, Orlando, FL 32827, USA
- College of Medicine, University of Central Florida, Orlando, FL 32827, USA
| | - Abinaya S Pugazhendhi
- Biionix Cluster, University of Central Florida, Orlando, FL 32827, USA
- College of Medicine, University of Central Florida, Orlando, FL 32827, USA
| | - Christopher Ngo
- Biionix Cluster, University of Central Florida, Orlando, FL 32827, USA
- College of Medicine, University of Central Florida, Orlando, FL 32827, USA
| | - Jonathan Ruiz
- College of Medicine, University of Central Florida, Orlando, FL 32827, USA
| | | | - Melanie J Coathup
- Biionix Cluster, University of Central Florida, Orlando, FL 32827, USA
- College of Medicine, University of Central Florida, Orlando, FL 32827, USA
| |
Collapse
|
4
|
Rigamonti AE, Dei Cas M, Caroli D, De Col A, Cella SG, Paroni R, Sartorio A. Identification of a Specific Plasma Sphingolipid Profile in a Group of Normal-Weight and Obese Subjects: A Novel Approach for a "Biochemical" Diagnosis of Metabolic Syndrome? Int J Mol Sci 2023; 24:ijms24087451. [PMID: 37108620 PMCID: PMC10138812 DOI: 10.3390/ijms24087451] [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: 03/22/2023] [Revised: 04/12/2023] [Accepted: 04/15/2023] [Indexed: 04/29/2023] Open
Abstract
Metabolic syndrome is nosographically defined by using clinical diagnostic criteria such as those of the International Diabetes Federation (IDF) ones, including visceral adiposity, blood hypertension, insulin resistance and dyslipidemia. Due to the pathophysiological implications of the cardiometabolic risk of the obese subject, sphingolipids, measured in the plasma, might be used to biochemically support the diagnosis of metabolic syndrome. A total of 84 participants, including normal-weight (NW) and obese subjects without (OB-SIMET-) and with (OB-SIMET+) metabolic syndrome, were included in the study, and sphingolipidomics, including ceramides (Cer), dihydroceramides (DHCer), hexosyl-ceramides (HexCer), lactosyl-ceramides (LacCer), sphingomyelins (SM) and GM3 ganglosides families, and sphingosine-1-phosphate (S1P) and its congeners, was performed in plasma. Only total DHCers and S1P were significantly higher in OB-SIMET+ than NW subjects (p < 0.05), while total Cers decreased in both obese groups, though statistical significance was reached only in OB-SIMET- (vs. NW) subjects (p < 0.05). When considering the comparisons of the single sphingolipid species in the obese groups (OB-SIMET- or OB-SIMET+) vs. NW subjects, Cer 24:0 was significantly decreased (p < 0.05), while Cer 24:1, DHCer 16:0, 18:0, 18:1 and 24:1, and SM 18:0, 18:1 and 24:1 were significantly increased (p < 0.05). Furthermore, taking into account the same groups for comparison, HexCer 22:0 and 24:0, and GM3 22:0 and 24:0 were significantly decreased (p < 0.05), while HexCer 24:1 and S1P were significantly increased (p < 0.05). After having analyzed all data via a PLS-DA-based approach, the subsequent determination of the VIP scores evidenced the existence of a specific cluster of 15 sphingolipids endowed with a high discriminating performance (i.e., VIP score > 1.0) among the three groups, including DHCer 18:0, DHCer 24:1, Cer 18:0, HexCer 22:0, GM3 24:0, Cer C24:1, SM 18:1, SM 18:0, DHCer 18:1, HexCer 24:0, SM 24:1, S1P, SM 16:0, HexCer 24:1 and LacCer 22:0. After having run a series of multiple linear regressions, modeled by inserting each sphingolipid having a VIP score > 1.0 as a dependent variable, and waist circumference (WC), systolic/diastolic blood pressures (SBP/DBP), homeostasis model assessment-estimated insulin resistance (HOMA-IR), high-density lipoprotein (HDL), triglycerides (TG) (surrogates of IDF criteria) and C-reactive protein (CRP) (a marker of inflammation) as independent variables, WC was significantly associated with DHCer 18:0, DHCer 24:1, Cer 18:0, HexCer 22:0, Cer 24:1, SM 18:1, and LacCer 22:0 (p < 0.05); SBP with Cer 18:0, Cer 24:1, and SM 18:0 (p < 0.05); HOMA-IR with DHCer 18:0, DHCer 24:1, Cer 18:0, Cer 24:1, SM 18:1, and SM 18:0 (p < 0.05); HDL with HexCer 22:0, and HexCer 24:0 (p < 0.05); TG with DHCer 18:1, DHCer 24:1, SM 18:1, and SM 16:0 (p < 0.05); CRP with DHCer 18:1, and SP1 (p < 0.05). In conclusion, a cluster of 15 sphingolipid species is able to discriminate, with high performance, NW, OB-SIMET- and OB-SIMET+ groups. Although (surrogates of) the IDF diagnostic criteria seem to predict only partially, but congruently, the observed sphingolipid signature, sphingolipidomics might represent a promising "biochemical" support for the clinical diagnosis of metabolic syndrome.
Collapse
Affiliation(s)
- Antonello E Rigamonti
- Department of Clinical Sciences and Community Health, University of Milan, 20129 Milan, Italy
| | - Michele Dei Cas
- Department of Health Sciences, University of Milan, 20142 Milan, Italy
| | - Diana Caroli
- Istituto Auxologico Italiano, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Experimental Laboratory for Auxo-Endocrinological Research, 28824 Piancavallo-Verbania, Italy
| | - Alessandra De Col
- Istituto Auxologico Italiano, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Experimental Laboratory for Auxo-Endocrinological Research, 28824 Piancavallo-Verbania, Italy
| | - Silvano G Cella
- Department of Clinical Sciences and Community Health, University of Milan, 20129 Milan, Italy
| | - Rita Paroni
- Department of Health Sciences, University of Milan, 20142 Milan, Italy
| | - Alessandro Sartorio
- Istituto Auxologico Italiano, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Experimental Laboratory for Auxo-Endocrinological Research, 28824 Piancavallo-Verbania, Italy
- Istituto Auxologico Italiano, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Experimental Laboratory for Auxo-Endocrinological Research, 20145 Milan, Italy
| |
Collapse
|
5
|
Xue Q, Zhang T, Zhu R, Qian Y, Dong X, Mo L, Jiang Y. Inhibition of Ceramide Synthesis Attenuates Chronic Ethanol Induced Cardiotoxicity by Restoring Lysosomal Function and Reducing Necroptosis. Alcohol Alcohol 2023; 58:164-174. [PMID: 36562604 DOI: 10.1093/alcalc/agac067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 11/21/2022] [Accepted: 11/21/2022] [Indexed: 12/24/2022] Open
Abstract
AIMS Chronic alcohol misuse could cause alcoholic cardiomyopathy (ACM), and the specific mechanisms remained largely unknown. In this study, we aimed to explore the effects of endogenous ceramides on chronic ethanol-induced myocardial injury or cell loss (e.g. necroptosis). METHODS We established chronic alcohol intoxication models in vivo (male C57BL/6 mice) and in vitro (H9c2 cardiomyoblasts). The ceramide profiles were analyzed in mice myocardium and cultured cardiomyocytes. Further research on the role of ceramides and underlying signaling pathways was carried out in H9c2 cells. RESULTS AND CONCLUSIONS The ceramide profiles analysis revealed increased long and very long-chain ceramides in alcoholic myocardium and ethanol-treated cardiomyocytes. Next, we proved that endogenous ceramide inhibition could reduce necroptosis and alleviate cardiomyocytes injury as suggested by decreased levels of p-RIPK1, p-RIPK3 and p-MLKL proteins and cardiac injury factors expression. Furthermore, we found that lysosomal dysfunction also contributed to alcohol-induced cardiac damage and inhibiting ceramide biosynthesis could repaired this to some extent. Cells studies with exogenous C6 ceramide confirmed the pleotropic roles of ceramide in myocardial damage by causing both necroptosis and lysosomal dysfunction. Finally, our data suggested that lysosomal dysfunction could sensitize cardiomyocytes to induction of necroptosis due to the restriction on degradation of RIPK1/RIPK3 proteins. In conclusion, chronic ethanol treatment boosted myocardial ceramide synthesis in animal hearts and cultured cardiomyocytes. Moreover, ceramides exerted crucial roles in the intrinsic signaling pathways of alcohol-induced cardiotoxicity. Targeting ceramide biosynthesis to simultaneously attenuate necroptosis and lysosomal dysfunction might be a novel strategy for preventing alcoholic cardiotoxicity.
Collapse
Affiliation(s)
- Qiupeng Xue
- Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, 131 Dongan Road, Xuhui District, Shanghai 200032, China
| | - Tianyi Zhang
- Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, 131 Dongan Road, Xuhui District, Shanghai 200032, China
| | - Rongzhe Zhu
- Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, 131 Dongan Road, Xuhui District, Shanghai 200032, China
| | - Yile Qian
- Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, 131 Dongan Road, Xuhui District, Shanghai 200032, China
| | - Xiaoru Dong
- Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, 131 Dongan Road, Xuhui District, Shanghai 200032, China
| | - Lingjie Mo
- Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, 131 Dongan Road, Xuhui District, Shanghai 200032, China
| | - Yan Jiang
- Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, 131 Dongan Road, Xuhui District, Shanghai 200032, China
| |
Collapse
|
6
|
Zhuo C, Zhao F, Tian H, Chen J, Li Q, Yang L, Ping J, Li R, Wang L, Xu Y, Cai Z, Song X. Acid sphingomyelinase/ceramide system in schizophrenia: implications for therapeutic intervention as a potential novel target. Transl Psychiatry 2022; 12:260. [PMID: 35739089 PMCID: PMC9226132 DOI: 10.1038/s41398-022-01999-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 05/24/2022] [Accepted: 05/25/2022] [Indexed: 11/09/2022] Open
Abstract
Schizophrenia is a severe mental illness, as the efficacies of current antipsychotic medications are far from satisfactory. An improved understanding of the signaling molecules involved in schizophrenia may provide novel therapeutic targets. Acid sphingomyelinase (ASM) catalyzes cellular membrane sphingomyelin into ceramide, which is further metabolized into sphingosine-1-phophate (S1P). ASM, ceramide, and S1P at the cell surface exert critical roles in the regulation of biophysical processes that include proliferation, apoptosis, and inflammation, and are thereby considered important signaling molecules. Although research on the ASM/ceramide system is still in its infancy, structural and metabolic abnormalities have been demonstrated in schizophrenia. ASM/ceramide system dysfunction is linked to the two important models of schizophrenia, the dopamine (DA) hypothesis through affecting presynaptic DA signaling, and the vulnerability-stress-inflammation model that includes the contribution of stress on the basis of genetic predisposition. In this review, we highlight the current knowledge of ASM/ceramide system dysfunction in schizophrenia gained from human and animal studies, and formulate future directions from the biological landscape for the development of new treatments. Collectively, these discoveries suggest that aberrations in the ASM/ceramide system, especially in ASM activity and levels of ceramide and S1P, may alter cerebral microdomain structure and neuronal metabolism, leading to neurotransmitter (e.g., DA) dysfunction and neuroinflammation. As such, the ASM/ceramide system may offer therapeutic targets for novel medical interventions. Normalization of the aberrant ASM/ceramide system or ceramide reduction by using approved functional inhibitors of ASM, such as fluvoxamine and rosuvastatin, may improve clinical outcomes of patients with schizophrenia. These transformative findings of the ASM/ceramide system in schizophrenia, although intriguing and exciting, may pose scientific questions and challenges that will require further studies for their resolution.
Collapse
Affiliation(s)
- Chuanjun Zhuo
- Key Laboratory of Real Time Tracing Brain Circuit, Tianjin Medical Affiliated Tianjin Fourth Center Hospital, Nankai University Affiliated Tianjin Fourth Center Hospital, Tianjin Fourth Hospital, 300140, Tianjin, China. .,The key Laboratory of Psychiatric-Neuroimaging-Genetics and Comorbidity (PNGC_Lab) of Tianjin Anding Hospital, Tianjin Mental Health Center of Tianjin Medical University, 300222, Tianjin, China. .,Brain Micro-imaging Center of Psychiatric Animal Model, Wenzhou Seventh Peoples Hospital, 325000, Wenzhou, China. .,Department of Psychiatry, The Fourth Center Hospital of Tianjin Medical University, 300222, Tianjin, China. .,Key Laboratory of the Macro-Brain Neuroimaging Center of Animal Model, Wenzhou Seventh Peoples Hospital, 325000, Wenzhou, China. .,Department of Psychiatry, The First Hospital of Shanxi Medical University, 03000, Taiyuan, China. .,Department of Psychiatry, First Affiliated Hospital of Zhengzhou University, 450052, Zhengzhou, China.
| | - Feifei Zhao
- Key Laboratory of the Macro-Brain Neuroimaging Center of Animal Model, Wenzhou Seventh Peoples Hospital, 325000 Wenzhou, China
| | - Hongjun Tian
- grid.265021.20000 0000 9792 1228Department of Psychiatry, The Fourth Center Hospital of Tianjin Medical University, 300222 Tianjin, China
| | - Jiayue Chen
- grid.265021.20000 0000 9792 1228Department of Psychiatry, The Fourth Center Hospital of Tianjin Medical University, 300222 Tianjin, China
| | - Qianchen Li
- grid.265021.20000 0000 9792 1228Department of Psychiatry, The Fourth Center Hospital of Tianjin Medical University, 300222 Tianjin, China
| | - Lei Yang
- grid.265021.20000 0000 9792 1228Department of Psychiatry, The Fourth Center Hospital of Tianjin Medical University, 300222 Tianjin, China
| | - Jing Ping
- Key Laboratory of the Macro-Brain Neuroimaging Center of Animal Model, Wenzhou Seventh Peoples Hospital, 325000 Wenzhou, China
| | - Ranli Li
- Key Laboratory of the Macro-Brain Neuroimaging Center of Animal Model, Wenzhou Seventh Peoples Hospital, 325000 Wenzhou, China
| | - Lina Wang
- Key Laboratory of the Macro-Brain Neuroimaging Center of Animal Model, Wenzhou Seventh Peoples Hospital, 325000 Wenzhou, China
| | - Yong Xu
- grid.452461.00000 0004 1762 8478Department of Psychiatry, The First Hospital of Shanxi Medical University, 03000 Taiyuan, China
| | - Ziyao Cai
- Key Laboratory of the Macro-Brain Neuroimaging Center of Animal Model, Wenzhou Seventh Peoples Hospital, 325000 Wenzhou, China
| | - Xueqin Song
- Department of Psychiatry, First Affiliated Hospital of Zhengzhou University, 450052, Zhengzhou, China.
| |
Collapse
|
7
|
Sharma D, Czarnota GJ. Involvement of Ceramide Signalling in Radiation-Induced Tumour Vascular Effects and Vascular-Targeted Therapy. Int J Mol Sci 2022; 23:ijms23126671. [PMID: 35743121 PMCID: PMC9223569 DOI: 10.3390/ijms23126671] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 05/31/2022] [Accepted: 06/06/2022] [Indexed: 02/04/2023] Open
Abstract
Sphingolipids are well-recognized critical components in several biological processes. Ceramides constitute a class of sphingolipid metabolites that are involved in important signal transduction pathways that play key roles in determining the fate of cells to survive or die. Ceramide accumulated in cells causes apoptosis; however, ceramide metabolized to sphingosine promotes cell survival and angiogenesis. Studies suggest that vascular-targeted therapies increase endothelial cell ceramide resulting in apoptosis that leads to tumour cure. Specifically, ultrasound-stimulated microbubbles (USMB) used as vascular disrupting agents can perturb endothelial cells, eliciting acid sphingomyelinase (ASMase) activation accompanied by ceramide release. This phenomenon results in endothelial cell death and vascular collapse and is synergistic with other antitumour treatments such as radiation. In contrast, blocking the generation of ceramide using multiple approaches, including the conversion of ceramide to sphingosine-1-phosphate (S1P), abrogates this process. The ceramide-based cell survival "rheostat" between these opposing signalling metabolites is essential in the mechanotransductive vascular targeting following USMB treatment. In this review, we aim to summarize the past and latest findings on ceramide-based vascular-targeted strategies, including novel mechanotransductive methodologies.
Collapse
Affiliation(s)
- Deepa Sharma
- Physical Sciences, Sunnybrook Health Sciences Centre, Toronto, ON M4N 3M5, Canada;
- Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto, ON M4N 3M5, Canada
- Departments of Medical Biophysics and Radiation Oncology, University of Toronto, Toronto, ON M4N 3M5, Canada
- Correspondence: ; Tel.: +1-416-480-6100 (ext. 89533)
| | - Gregory J. Czarnota
- Physical Sciences, Sunnybrook Health Sciences Centre, Toronto, ON M4N 3M5, Canada;
- Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto, ON M4N 3M5, Canada
- Departments of Medical Biophysics and Radiation Oncology, University of Toronto, Toronto, ON M4N 3M5, Canada
| |
Collapse
|
8
|
Soteriou C, Kalli AC, Connell SD, Tyler AII, Thorne JL. Advances in understanding and in multi-disciplinary methodology used to assess lipid regulation of signalling cascades from the cancer cell plasma membrane. Prog Lipid Res 2020; 81:101080. [PMID: 33359620 DOI: 10.1016/j.plipres.2020.101080] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 12/18/2020] [Accepted: 12/18/2020] [Indexed: 12/31/2022]
Abstract
The lipid bilayer is a functional component of cells, forming a stable platform for the initiation of key biological processes, including cell signalling. There are distinct changes in the lipid composition of cell membranes during oncogenic transformation resulting in aberrant activation and inactivation of signalling transduction pathways. Studying the role of the cell membrane in cell signalling is challenging, since techniques are often limited to by timescale, resolution, sensitivity, and averaging. To overcome these limitations, combining 'computational', 'wet-lab' and 'semi-dry' approaches offers the best opportunity to resolving complex biological processes involved in membrane organisation. In this review, we highlight analytical tools that have been applied for the study of cell signalling initiation from the cancer cell membranes through computational microscopy, biological assays, and membrane biophysics. The cancer therapeutic potential of extracellular membrane-modulating agents, such as cholesterol-reducing agents is also discussed, as is the need for future collaborative inter-disciplinary research for studying the role of the cell membrane and its components in cancer therapy.
Collapse
Affiliation(s)
- C Soteriou
- School of Food Science and Nutrition, University of Leeds, Leeds LS29JT, UK; Leeds Institute of Cardiovascular and Metabolic Medicine and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK; Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK
| | - A C Kalli
- Leeds Institute of Cardiovascular and Metabolic Medicine and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK
| | - S D Connell
- Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK
| | - A I I Tyler
- School of Food Science and Nutrition, University of Leeds, Leeds LS29JT, UK
| | - J L Thorne
- School of Food Science and Nutrition, University of Leeds, Leeds LS29JT, UK.
| |
Collapse
|
9
|
Abstract
The global prevalence of metabolic diseases such as type 2 diabetes mellitus, steatohepatitis, myocardial infarction, and stroke has increased dramatically over the past two decades. These obesity-fueled disorders result, in part, from the aberrant accumulation of harmful lipid metabolites in tissues not suited for lipid storage (e.g., the liver, vasculature, heart, and pancreatic beta-cells). Among the numerous lipid subtypes that accumulate, sphingolipids such as ceramides are particularly impactful, as they elicit the selective insulin resistance, dyslipidemia, and ultimately cell death that underlie nearly all metabolic disorders. This review summarizes recent findings on the regulatory pathways controlling ceramide production, the molecular mechanisms linking the lipids to these discrete pathogenic events, and exciting attempts to develop therapeutics to reduce ceramide levels to combat metabolic disease.
Collapse
Affiliation(s)
- Bhagirath Chaurasia
- Department of Internal Medicine, Division of Endocrinology, Fraternal Order of Eagles Diabetes Research Center, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA;
| | - Scott A Summers
- Department of Nutrition and Integrative Physiology and the Diabetes and Metabolism Research Center, University of Utah, Salt Lake City, Utah 84112, USA;
| |
Collapse
|
10
|
Pant DC, Aguilera-Albesa S, Pujol A. Ceramide signalling in inherited and multifactorial brain metabolic diseases. Neurobiol Dis 2020; 143:105014. [PMID: 32653675 DOI: 10.1016/j.nbd.2020.105014] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 06/13/2020] [Accepted: 07/07/2020] [Indexed: 12/14/2022] Open
Abstract
In recent years, research on sphingolipids, particularly ceramides, has attracted increased attention, revealing the important roles and many functions of these molecules in several human neurological disorders. The nervous system is enriched with important classes of sphingolipids, e.g., ceramide and its derivatives, which compose the major portion of this group, particularly in the form of myelin. Ceramides have also emerged as important nodes for lipid signalling, both inside the cell and between cells. Until recently, knowledge about ceramides in the nervous system was limited, but currently, multiple links between ceramide signalling and neurological diseases have been reported. Alterations in the regulation of ceramide pathobiology have been shown to influence the risk of developing neurometabolic diseases. Thus, these molecules are critically important in the maintenance and development of the nervous system and are culprits or major contributors to the development of brain disorders, either inherited or multifactorial. In the present review, we highlight the critical role of ceramide signalling in several different neurological disorders as well as the effects of their perturbations and discuss how this emerging class of bioactive sphingolipids has attracted interest in the field of neurological diseases.
Collapse
Affiliation(s)
- Devesh C Pant
- Department of Biology, Georgia State University, Atlanta, GA 30303, USA
| | - Sergio Aguilera-Albesa
- Pediatric Neurology Unit, Department of Pediatrics, Navarra Health Service Hospital, Irunlarrea 4, 310620 Pamplona, Spain; Navarrabiomed-Miguel Servet Research Foundation, Pamplona, Spain
| | - Aurora Pujol
- Neurometabolic Diseases Laboratory, IDIBELL, Hospital Duran i Reynals, Gran Via 199, 08908, L'Hospitalet de Llobregat, Barcelona, Spain; Catalan Institution of Research and Advanced Studies (ICREA), Barcelona, Catalonia, Spain; Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain.
| |
Collapse
|
11
|
Abstract
Adipose tissue is a key nutrient-sensing depot that regulates excess energy storage and consumption. Adipocytes, the key components of the adipose tissue, have unique ability to store excess energy in the form of triglycerides, sense systemic energy demands, and secrete factors (lipids, peptides, cytokines, and adipokines) to regulate other metabolic tissues. The presence of various types of adipocytes (white, brown, and beige) characterized by the number/size of lipid droplets, mitochondrial density, and thermogenic capacity, further highlights how intricate is the communication of these cell-types with other metabolic tissues to sense nutrients. In obesity the inherent capacity of adipose tissue to store and sense nutrients is compromised, causing spillover of the intermediate lipid metabolites into circulation and resulting in their ectopic deposition in tissues not suitable for lipid storage, a phenomenon known as lipotoxicity. This results in a spectrum of cellular dysfunction, that underlies various metabolic diseases. Of the numerous lipid classes implicated in eliciting lipotoxicity, sphingolipid: ceramides are among the most deleterious as they modulate signaling pathways involved in regulating glucose metabolism, triglyceride synthesis, apoptosis, and fibrosis. Notably, recent experimental studies have strongly implicated ceramides in the development of numerous metabolic diseases such as insulin resistance, diabetes, cardiomyopathy, hepatic-steatosis, and atherosclerosis. Herein we discuss and summarizes recent findings that implicate ceramides as a key contributor to adipocyte dysfunction underlying metabolic diseases and how depletion of ceramides can be exploited to improve metabolic health.
Collapse
Affiliation(s)
- Ying Li
- Department of Nutrition and Integrative Physiology, The Diabetes and Metabolism Research Center, University of Utah, Salt Lake City, UT, United States
| | - Chad Lamar Talbot
- Department of Nutrition and Integrative Physiology, The Diabetes and Metabolism Research Center, University of Utah, Salt Lake City, UT, United States
| | - Bhagirath Chaurasia
- Department of Nutrition and Integrative Physiology, The Diabetes and Metabolism Research Center, University of Utah, Salt Lake City, UT, United States
- Division of Endocrinology, Department of Internal Medicine, Fraternal Order of Eagles Diabetes Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| |
Collapse
|
12
|
Abstract
Ceramides are products of metabolism that accumulate in individuals with obesity or dyslipidaemia and alter cellular processes in response to fuel surplus. Their actions, when prolonged, elicit the tissue dysfunction that underlies diabetes and heart disease. Here, we review the history of research on these enigmatic molecules, exploring their discovery and mechanisms of action, the evolutionary pressures that have given them their unique attributes and the potential of ceramide-reduction therapies as treatments for cardiometabolic disease.
Collapse
Affiliation(s)
- Scott A Summers
- Department of Nutrition and Integrative Physiology and the Diabetes and Metabolism Center, University of Utah, Salt Lake City, UT, USA.
| | - Bhagirath Chaurasia
- Department of Nutrition and Integrative Physiology and the Diabetes and Metabolism Center, University of Utah, Salt Lake City, UT, USA
| | - William L Holland
- Department of Nutrition and Integrative Physiology and the Diabetes and Metabolism Center, University of Utah, Salt Lake City, UT, USA
| |
Collapse
|
13
|
Abiraterone and Ionizing Radiation Alter the Sphingolipid Homeostasis in Prostate Cancer Cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1112:293-307. [DOI: 10.1007/978-981-13-3065-0_20] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
14
|
Knapp P, Bodnar L, Błachnio-Zabielska A, Świderska M, Chabowski A. Plasma and ovarian tissue sphingolipids profiling in patients with advanced ovarian cancer. Gynecol Oncol 2017; 147:139-144. [PMID: 28800942 DOI: 10.1016/j.ygyno.2017.07.143] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 07/27/2017] [Accepted: 07/30/2017] [Indexed: 10/19/2022]
Abstract
PURPOSE The role of lipids in carcinogenesis through induction of abnormal cell lines in the human body is currently undisputable. Based on the literature, bioactive sphingolipids play an essential role in the development and progression of cancer and are involved in the metastatic process. The aim of this study was to determine the concentration of selected sphingolipids in patients with advanced ovarian cancer (AOC, FIGO III/IV, high grade ovarian cancer). METHODS Seventy-four patients with ovarian cancer were enrolled. Plasma concentrations of C16-Cer, C18:1-Cer and C18-Cer were assessed by LC/MS/MS. The content of tissue sphingolipids was measured using a UHPLC/MS/MS. RESULTS Plasma concentration of 3 ceramides: C16-Cer, C18:1-Cer and C18-Cer was significantly elevated in women with advanced ovarian cancer compared to control group (P=0.031; 0.022; 0.020; respectively). There were increases in concentration of 5 ceramides: C16-Cer, C18:1-Cer, C18-Cer, C24:1-Cer, C24-Cer (P=0.025; 0.049; 0.032; 0.005; 0.013, respectively) and S1P (P=0.004) in ovarian tissue of women with advanced ovarian cancer compared to healthy individuals. Importantly, significantly higher risk of ovarian cancer when the plasma concentration of C16-Cer>311.88ng/100μl (AUC: 0.76, P=0.0261); C18:1-Cer>4.75ng/100μl (AUC: 0.77, P=0.0160) and C18-Cer>100.76ng/100μl (AUC:0.77, P=0.0136) was noticed. CONCLUSIONS Bioactive sphingolipids play an essential role in the development and progression of cancer and they also take part in the process of metastasizing. This study suggests that some sphingolipids can be used as potential biomarkers of advanced ovarian cancer and that they can play an important role in the pathogenesis of this disease.
Collapse
Affiliation(s)
- Paweł Knapp
- Department of Gynecology and Gynecologic Oncology, Medical University of Bialystok, 24a Sklodowskiej-Curie Str., 15-276 Bialystok, Poland.
| | - Lubomir Bodnar
- Department of Clinical Oncology, Military Institute of Medicine in Warsaw, 128 Szaserow Str., 04-141 Warsaw, Poland.
| | - Agnieszka Błachnio-Zabielska
- Department of Hygiene, Epidemiology and Metabolic Disorders, Medical University of Bialystok, 2c Mickiewicza Str., 15-222 Bialystok, Poland; Department of Physiology, Medical University of Bialystok, 2c Mickiewicza Str., 15-222 Bialystok, Poland.
| | - Magdalena Świderska
- Department of Physiology, Medical University of Bialystok, 2c Mickiewicza Str., 15-222 Bialystok, Poland.
| | - Adrian Chabowski
- Department of Physiology, Medical University of Bialystok, 2c Mickiewicza Str., 15-222 Bialystok, Poland.
| |
Collapse
|
15
|
Lee WK, Kolesnick RN. Sphingolipid abnormalities in cancer multidrug resistance: Chicken or egg? Cell Signal 2017; 38:134-145. [PMID: 28687494 DOI: 10.1016/j.cellsig.2017.06.017] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 06/25/2017] [Accepted: 06/25/2017] [Indexed: 12/12/2022]
Abstract
The cancer multidrug resistance (MDR) phenotype encompasses a myriad of molecular, genetic and cellular alterations resulting from progressive oncogenic transformation and selection. Drug efflux transporters, in particular the MDR P-glycoprotein ABCB1, play an important role in MDR but cannot confer the complete phenotype alone indicating parallel alterations are prerequisite. Sphingolipids are essential constituents of lipid raft domains and directly participate in functionalization of transmembrane proteins, including providing an optimal lipid microenvironment for multidrug transporters, and are also perturbed in cancer. Here we postulate that increased sphingomyelin content, developing early in some cancers, recruits and functionalizes plasma membrane ABCB1 conferring a state of partial MDR, which is completed by glycosphingolipid disturbance and the appearance of intracellular vesicular ABCB1. In this review, the independent and interdependent roles of sphingolipid alterations and ABCB1 upregulation during the transformation process and resultant conferment of partial and complete MDR phenotypes are discussed.
Collapse
Affiliation(s)
- Wing-Kee Lee
- Laboratory of Signal Transduction, Sloan Kettering Institute for Cancer Research, Memorial Sloan-Kettering Cancer Center, New York, United States; Institute for Physiology, Pathophysiology and Toxicology, Centre for Biomedical Education and Research (ZBAF), Witten/Herdecke University, Witten, Germany.
| | - Richard N Kolesnick
- Laboratory of Signal Transduction, Sloan Kettering Institute for Cancer Research, Memorial Sloan-Kettering Cancer Center, New York, United States
| |
Collapse
|
16
|
Kobayashi K, Ishizaki Y, Kojo S, Kikuzaki H. Strong Inhibition of Secretory Sphingomyelinase by Catechins, Particularly by (-)-Epicatechin 3-O-Gallate and (-)-3'-O-Methylepigallocatechin 3-O-Gallate. J Nutr Sci Vitaminol (Tokyo) 2017; 62:123-9. [PMID: 27264097 DOI: 10.3177/jnsv.62.123] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Sphingomyelinases (SMases) are key enzymes involved in many diseases which are caused by oxidative stress, such as atherosclerosis, diabetes mellitus, nonalcoholic fatty liver disease, and Alzheimer's disease. SMases hydrolyze sphingomyelin to generate ceramide, a well-known pro-apoptotic lipid. SMases are classified into five types based on pH optimum, subcellular localization, and cation dependence. Previously, we demonstrated that elevation of secretory sphingomyelinase (sSMase) activity increased the plasma ceramide concentration under oxidative stress induced by diabetes and atherosclerosis in murine models. These results suggest that sSMase inhibitors can prevent the progress of these diseases. The present study demonstrated that sSMase activity was activated by oxidation and inhibited by reduction. Furthermore, we examined whether catechins inhibited the sSMase activity in a physiological plasma concentration. Among catechins, (-)-epicatechin 3-O-gallate (ECg) exhibited strong inhibitory effect on sSMase (IC50=25.7 μM). This effect was attenuated by methylation at the 3″- or 4″-position. On the other hand, (-)-epigallocatechin 3-O-gallate (EGCg) and (-)-catechin 3-O-gallate (Cg) exhibited weaker inhibitory activity than ECg, and (-)-epicatechin and (-)-epigallocatechin did not affect sSMase activity. Additionally, one synthetic catechin, (-)-3'-O-methylepigallocatechin 3-O-gallate (EGCg-3'-O-Me), showed the strongest inhibitory effect (IC50=1.7 μM) on sSMase. This phenomenon was not observed for (-)-4'-O-methylepigallocatechin 3-O-gallate. These results suggest that the reduction potential, the presence of the galloyl residue at the C-3 position, and the steric requirement to interact with sSMase protein are important for effective inhibition of sSMase.
Collapse
Affiliation(s)
- Keiko Kobayashi
- Department of Food Science and Nutrition, Nara Women's University
| | | | | | | |
Collapse
|
17
|
Kim SH, Um SI, Nam Y, Park SY, Dong JH, Ko SK, Sohn UD, Lee SJ. The effect of synthetic ceramide analogues on gastritis and esophagitis in rats. Arch Pharm Res 2016; 39:1313-23. [PMID: 27393666 DOI: 10.1007/s12272-016-0792-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 06/30/2016] [Indexed: 01/29/2023]
Abstract
The effects of ceremide analogues on esophagitis and gastritis in rats were examined. Gastritis induced by indomethacin was significantly reduced after CY3325 and CY3723 treatment, whereas other analogues had no effect. The amount of malondialdehyde in gastritis was significantly reduced by CY3325 or CY 3723. CY3325 or CY 3723 decreased the glutathione levels in gastritis. The myeloperoxidase level in gastritis is increased, and its increment was decreased by CY3325 and CY3723. In reflux esophagitis, the ulceration was decreased by CY3325, CY3723. The gastric volume and acid output are reduced, whereas the pH value is increased by CY3325 or CY3723 after esophagitis. These results suggest that ceramide analogues, CY3325 and CY3723, can prevent the development of gastritis and reflux esophagitis in rats.
Collapse
Affiliation(s)
- Sung Hyo Kim
- Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul, 156-756, Republic of Korea
| | - Seung In Um
- Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul, 156-756, Republic of Korea
| | - Yoonjin Nam
- Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul, 156-756, Republic of Korea
| | - Sun Young Park
- Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul, 156-756, Republic of Korea
| | - Je Hyun Dong
- Department of Pharmacology, College of Pharmacy, Catholic University of Daegu, Gyeongsan, 38430, Republic of Korea
| | - Sung Kwon Ko
- Department of Oriental Medical Food & Nutrition, Semyung University, Jecheon, Choongbuk, 27136, Republic of Korea
| | - Uy Dong Sohn
- Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul, 156-756, Republic of Korea.
| | - Sang Joon Lee
- Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul, 156-756, Republic of Korea.
| |
Collapse
|
18
|
Gomez-Muñoz A, Gangoiti P, Rivera IG, Presa N, Gomez-Larrauri A, Ordoñez M. Caged ceramide 1-phosphate (C1P) analogs: Novel tools for studying C1P biology. Chem Phys Lipids 2016; 194:79-84. [DOI: 10.1016/j.chemphyslip.2015.07.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 07/14/2015] [Accepted: 07/27/2015] [Indexed: 12/12/2022]
|
19
|
Lo JM, Wang WL, Chiang YM, Chen CM. Ceramides from the Taiwan Red AlgaCeratodictyon Spongiosumand Symbiotic SpongeSigmadocia Symbiotica. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.200100118] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
20
|
Kobayashi K, Ichi I, Nakagawa T, Kamikawa C, Kitamura Y, Koga E, Washino Y, Hoshinaga Y, Kojo S. Increase in plasma ceramide levels via secretory sphingomyelinase activity in streptozotocin-induced diabetic rats. MEDCHEMCOMM 2011. [DOI: 10.1039/c0md00154f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
21
|
Ichi I, Kamikawa C, Nakagawa T, Kobayashi K, Kataoka R, Nagata E, Kitamura Y, Nakazaki C, Matsura T, Kojo S. Neutral sphingomyelinase-induced ceramide accumulation by oxidative stress during carbon tetrachloride intoxication. Toxicology 2009; 261:33-40. [PMID: 19394401 DOI: 10.1016/j.tox.2009.04.040] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Revised: 04/14/2009] [Accepted: 04/15/2009] [Indexed: 12/12/2022]
Abstract
Ceramide is a biologically active lipid causing apoptosis in a variety of cells. In this study, we examined the effect of CCl4 on the ceramide metabolism and indicators of oxidative stress. After 12 h of oral administration of CCl4 (4 ml/kg body weight as a 1:1 mixture of CCl4 and mineral oil) to rats, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were increased. Antioxidants such as vitamins C and E were decreased in the liver and kidney. In addition, the ratio of GSH/GSSG in the liver, plasma, kidney, and brain decreased at 2h. The total ceramide in the liver significantly increased as early as 2h after CCl4 administration. After 24 and 36 h, the total ceramide in plasma and the kidney was also augmented. In the brain, the total ceramide dramatically increased at 36 h. These results suggested that the increased ceramide in plasma was transferred to the kidney and the brain. The activity of neutral sphingomyelinase (SMase), which was reported to be enhanced by the decrease of GSH, was significantly increased after CCl4 treatment in the liver, kidney, and brain. However, acid SMase activities were not increased in the liver and kidney. Thus, the activation of neutral SMase via oxidative stress induced the increase of ceramide during CCl4 intoxication in not only the liver but also other tissues. These results suggested that the excess accumulation of ceramide causes damage in other organs including the kidney and brain during fulminant hepatic failure.
Collapse
Affiliation(s)
- Ikuyo Ichi
- Department of Food Science and Nutrition, Nara Women's University, Nara 630-8506, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Lim JY, Kumar P, Lee YI. Investigation on C2-ceramide complexes with transition metal ions using electrospray ionization tandem mass spectrometry. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2008; 14:87-97. [PMID: 18493098 DOI: 10.1255/ejms.915] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Electrospray ionization-tandem mass spectrometry (ESI-MS/MS) is applied for the investigation of C(2)-ceramide complexes with transition metal ions. Ceramide plays an important role in the regulation of various signaling pathways leading to proliferation, differentiation or apoptotic cell death. The formation and fragmentation of doubly charged cluster ions as well as singly charged cluster ions of C(2)-ceramide with transition metal ions (Mn(2+), Fe(2+), Co(2+) and Ni(2+)) are studied by ESI-MS/MS in the positive mode. Tube lens offset voltage and concentrations of C(2)-ceramide and transition metals are optimized to determine the best conditions for generating doubly charged cluster ions. The fragmentation pathways of metal ion complexes with C(2)-ceramide and the compositions of these complexes are determined by collision induced dissociation (CID). All transition metal ions (Mn(2+), Fe(2+), Co(2+) and Ni(2+) except Cu(2+)) shows similar complexation with C(2) ceramide. The unique complexation behavior of copper(II) is responsible for the different geometry of the complexes and relatively lower affinity of ceramide to copper(II) than those to other transition metals.
Collapse
Affiliation(s)
- Jin-Yi Lim
- Department of Chemistry, Changwon National University, Changwon 641-773, Korea
| | | | | |
Collapse
|
23
|
Ichi I, Takashima Y, Adachi N, Nakahara K, Kamikawa C, Harada-Shiba M, Kojo S. Effects of dietary cholesterol on tissue ceramides and oxidation products of apolipoprotein B-100 in ApoE-deficient mice. Lipids 2007; 42:893-900. [PMID: 17647040 DOI: 10.1007/s11745-007-3067-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Accepted: 04/20/2007] [Indexed: 12/24/2022]
Abstract
Oxidized LDL (oxLDL) has been shown to activate the sphingomyelinase pathway producing ceramide in vascular smooth muscle cells. Therefore ceramide, which is a biologically active lipid causing apoptosis in a variety of cells, may be involved in the apoptotic action of oxLDL. In this study, we examined whether cholesterol enriched diets affected ceramide metabolism and oxidation product of LDL, represented by degradation of apolipoprotein B-100 (apoB) in apoE-deficient (apoE-/-) mice. ApoE-/- and wild type mice were fed a standard (AIN-76) diet or 1% cholesterol-enriched diet for 8 weeks. Tissue ceramide levels were analyzed using electrospray tandem mass spectrometry (LC-MS/MS). Ceramide levels in the plasma and the liver of apoE-/- mice were intrinsically higher than those of the wild type. In apoE-/- mice, dietary cholesterol significantly increased several ceramides and degradation products of apoB in plasma compared to those fed the control diet. Dietary cholesterol did not affect tissue ceramide levels in the wild type mice. Based on these results, plasma ceramides possibly correlate with the increase in LDL oxidation and are a risk factor for atherosclerosis.
Collapse
Affiliation(s)
- Ikuyo Ichi
- Department of Food Science and Nutrition, Nara Women's University, Nara 630-8506, Japan
| | | | | | | | | | | | | |
Collapse
|
24
|
Ichi I, Nakahara K, Kiso K, Kojo S. Effect of dietary cholesterol and high fat on ceramide concentration in rat tissues. Nutrition 2007; 23:570-4. [PMID: 17566704 DOI: 10.1016/j.nut.2007.04.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2006] [Revised: 03/02/2007] [Accepted: 04/27/2007] [Indexed: 10/23/2022]
Abstract
OBJECTIVE Recent studies have indicated that plasma sphingomyelin levels and sphingomyelinase activity are risk factors for atherosclerosis. Therefore, it is suggested that ceramides, which are hydrolyzed products of sphingomyelin and a biologically active lipid causing apoptosis in a variety of cells, have an important role in the incidence of atherosclerosis. In this study, we examined whether cholesterol- and fat-enriched diets, which are causes of atherosclerosis, affect ceramide metabolism. In addition, we found a relation among lipid markers of atherosclerosis such as cholesterol, triacylglycerol, and ceramide concentrations. METHODS Male Wistar rats were fed a diet supplemented with 1% cholesterol or 30% high-fat diet for 8 wk. Tissue ceramide levels were analyzed using electrospray tandem mass spectrometry. RESULTS The major ceramides in plasma and the liver were C24:0 and C24:1. The major ceramides in adipose tissues were C16:0 and C24:0. Therefore, the ceramide composition of the adipose tissues was different from that of plasma and the liver. In addition, total ceramide levels in plasma and the adipose tissues of rats fed cholesterol were higher than those in the control group. CONCLUSION The accumulation of cholesterol caused an increase in ceramides, which might be a new risk factor for atherosclerosis.
Collapse
Affiliation(s)
- Ikuyo Ichi
- Department of Food Science and Nutrition, Nara Women's University, Nara, Japan
| | | | | | | |
Collapse
|
25
|
Ichi I, Nakahara K, Miyashita Y, Hidaka A, Kutsukake S, Inoue K, Maruyama T, Miwa Y, Harada-Shiba M, Tsushima M, Kojo S. Association of ceramides in human plasma with risk factors of atherosclerosis. Lipids 2007; 41:859-63. [PMID: 17152923 DOI: 10.1007/s11745-006-5041-6] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Atherosclerosis is a multifactorial disorder. Recent studies indicate that the plasma level of sphingomyelin, which yields ceramide, correlates with the risk of coronary heart disease. Therefore, ceramide, a well-known lipid causing apoptosis in various cell types, may contribute to atherogenesis. We examined the relationship between ceramide concentration and risk factors of atherosclerosis in normal human plasma using electrospray tandem mass spectrometry (LC-MS/MS). Major ceramides in human plasma were C24:0 and C24:1. The ceramide concentration showed a significant positive correlation with total cholesterol (TC) and triglycerides (TG). In addition, plasma ceramide level increased drastically at a high level of LDL cholesterol (more than 170 mg/dL). Our previous studies demonstrated that the sum of fragmented and conjugated apolipoprotein B-100 proteins (B-ox), which were products of a radical reaction of LDL as well as plasma, was a reliable index of atherosclerosis. B-ox showed a significant positive correlation with the plasma ceramide level. Based on these results, we propose that the ceramide level in human plasma is a risk factor at the early stages of atherosclerosis.
Collapse
Affiliation(s)
- Ikuyo Ichi
- Department of Food Science and Nutrition, Nara Women's University, Nara 630-8506, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Futerman AH. Intracellular trafficking of sphingolipids: relationship to biosynthesis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2006; 1758:1885-92. [PMID: 16996025 DOI: 10.1016/j.bbamem.2006.08.004] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Accepted: 08/09/2006] [Indexed: 01/12/2023]
Abstract
The intracellular routes of sphingolipid trafficking are related to the compartmentalized nature of sphingolipid metabolism, with synthesis beginning in the endoplasmic reticulum, continuing in the Golgi apparatus, and degradation occurring mainly in lysosomes. Whereas bulk sphingolipid transport between subcellular organelles occurs primarily via vesicle-mediated pathways, evidence is accumulating that sphingolipids are found in subcellular organelles that are not connected to each other by vesicular flow, implying additional trafficking routes. After discussing how sphingolipids are transported through the secretory pathway, I will review evidence for sphingolipid metabolism in organelles such as the mitochondria, and then discuss how this impacts upon our current understanding of the regulation of intracellular sphingolipid transport.
Collapse
Affiliation(s)
- Anthony H Futerman
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
| |
Collapse
|
27
|
Abstract
In this review focus is given to the metabolic turnover of gangliosides/glycosphingolipids. The metabolism and accompanying intracellular trafficking of gangliosides/glycosphingolipids is illustrated with particular attention to the following events: (a) the de novo biosynthesis in the endoplasmic reticulum and Golgi apparatus, followed by vesicular sorting to the plasma membrane; (b) the enzyme-assisted chemical modifications occurring at the plasma membrane level; (c) the internalization via endocytosis and recycling to the plasma membrane; (d) the direct glycosylations taking place after sorting from endosomes to the Golgi apparatus; (e) the degradation at the late endosomal/lysosomal level with formation of fragments of sugar (glucose, galactose, hexosamine, sialic acid) and lipid (ceramide, sphingosine, fatty acid) nature; (f) the metabolic recycling of these fragments for biosynthetic purposes (salvage pathways); and (g) further degradation of fragments to waste products. Noteworthy, the correct course of ganglioside/glycosphingolipid metabolism requires the presence of the vimentin intracellular filament net work, likely to assist intracellular transport of sphingoid molecules. ut of the above events those that can be quantitatively evaluated with acceptable reliability are the processes of de novo biosynthesis, metabolic salvage and direct glycosylation. Depending on the cultured cells employed, the percentage of distribution of de novo biosynthesis, salvage pathways, and direct glycosylation, over total metabolism were reported to be: 35% (range: 10-90%) for de novo biosynthesis, 7% (range: 5-10%) for direct glycosylation, and 58% (range: 10-90%) for salvage pathways. The attempts made to calculate the half-life of overall ganglioside turnover provided data of unsure reliability, especially because in many studies salvage pathways were not taken into consideration. The values of half-life range from 2 to 6.5 h to 3 days depending on the cells used. Available evidence for changes of ganglioside/glycosphingolipid turnover, due to extracellular stimuli, is also considered and discussed.
Collapse
Affiliation(s)
- G Tettamanti
- Department of Medical Chemistry, Biochemistry and Biotechnology, and Study Center for the Functional Biochemistry and Biotechnology of Glycolipids, The Medical School, University of Milan, Italy.
| |
Collapse
|
28
|
Han G, Gable K, Yan L, Natarajan M, Krishnamurthy J, Gupta SD, Borovitskaya A, Harmon JM, Dunn TM. The topology of the Lcb1p subunit of yeast serine palmitoyltransferase. J Biol Chem 2004; 279:53707-16. [PMID: 15485854 DOI: 10.1074/jbc.m410014200] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The structural organization and topology of the Lcb1p subunit of yeast and mammalian serine palmitoyltransferases (SPT) were investigated. In the yeast protein, three membrane-spanning domains were identified by insertion of glycosylation and factor Xa cleavage sites at various positions. The first domain of the yeast protein, located between residues 50 and 84, was not required for the stability, membrane association, interaction with Lcb2p, or enzymatic activity. Deletion of the comparable domain of the mammalian protein SPTLC1 also had little effect on its function, demonstrating that this region is not required for membrane localization or heterodimerization with SPTLC2. The second and third membrane-spanning domains of yeast Lcb1p, located between residues 342 and 371 and residues 425 and 457, respectively, create a luminal loop of approximately 60 residues. In contrast to the first membrane-spanning domain, the second and third membrane-spanning domains were both required for Lcb1p stability. In addition, mutations in the luminal loop destabilized the SPT heterodimer indicating that this region of the protein is important for SPT structure and function. Mutations in the extreme carboxyl-terminal region of Lcb1p also disrupted heterodimer formation. Taken together, these data suggest that in contrast to other members of the alpha-oxoamine synthases that are soluble homodimers, the Lcb1p and Lcb2p subunits of the SPT heterodimer may interact in the cytosol, as well as within the membrane and/or the lumen of the endoplasmic reticulum.
Collapse
Affiliation(s)
- Gongshe Han
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Rd., Bethesda, MD 20184-4799, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Bentires-Alj M, Barbu V, Fillet M, Chariot A, Relic B, Jacobs N, Gielen J, Merville MP, Bours V. NF-kappaB transcription factor induces drug resistance through MDR1 expression in cancer cells. Oncogene 2003; 22:90-7. [PMID: 12527911 DOI: 10.1038/sj.onc.1206056] [Citation(s) in RCA: 335] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The ubiquitous NF-kappaB transcription factor has been reported to inhibit apoptosis and to induce drug resistance in cancer cells. Drug resistance is the major reason for cancer therapy failure and neoplastic cells often develop multiple mechanisms of drug resistance during tumor progression. We observed that NF-kappaB or P-glycoprotein inhibition in the HCT15 colon cancer cells led to increased apoptotic cell death in response to daunomycin treatment. Interestingly, NF-kappaB inhibition through transfection of a plasmid coding for a mutated IkappaB-alpha inhibitor increased daunomycin cell uptake. Indeed, the inhibition of NF-kappaB reduced mdr1 mRNA and P-glycoprotein expression in HCT15 cells. We identified a consensus NF-kappaB binding site in the first intron of the human mdr1 gene and demonstrated that NF-kappaB complexes could bind with this intronic site. Moreover, NF-kappaB transactivates an mdr1 promoter luciferase construct. Our data thus demonstrate a role for NF-kappaB in the regulation of the mdr1 gene expression in cancer cells and in drug resistance.
Collapse
|
30
|
Murer H, Hernando N, Forster I, Biber J. Proximal tubular phosphate reabsorption: molecular mechanisms. Physiol Rev 2000; 80:1373-409. [PMID: 11015617 DOI: 10.1152/physrev.2000.80.4.1373] [Citation(s) in RCA: 390] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Renal proximal tubular reabsorption of P(i) is a key element in overall P(i) homeostasis, and it involves a secondary active P(i) transport mechanism. Among the molecularly identified sodium-phosphate (Na/P(i)) cotransport systems a brush-border membrane type IIa Na-P(i) cotransporter is the key player in proximal tubular P(i) reabsorption. Physiological and pathophysiological alterations in renal P(i) reabsorption are related to altered brush-border membrane expression/content of the type IIa Na-P(i) cotransporter. Complex membrane retrieval/insertion mechanisms are involved in modulating transporter content in the brush-border membrane. In a tissue culture model (OK cells) expressing intrinsically the type IIa Na-P(i) cotransporter, the cellular cascades involved in "physiological/pathophysiological" control of P(i) reabsorption have been explored. As this cell model offers a "proximal tubular" environment, it is useful for characterization (in heterologous expression studies) of the cellular/molecular requirements for transport regulation. Finally, the oocyte expression system has permitted a thorough characterization of the transport characteristics and of structure/function relationships. Thus the cloning of the type IIa Na-P(i )cotransporter (in 1993) provided the tools to study renal brush-border membrane Na-P(i) cotransport function/regulation at the cellular/molecular level as well as at the organ level and led to an understanding of cellular mechanisms involved in control of proximal tubular P(i) handling and, thus, of overall P(i) homeostasis.
Collapse
Affiliation(s)
- H Murer
- Institute of Physiology, University of Zürich, Zürich, Switzerland.
| | | | | | | |
Collapse
|
31
|
Morales CR, Zhao Q, Lefrancois S, Ham D. Role of prosaposin in the male reproductive system: effect of prosaposin inactivation on the testis, epididymis, prostate, and seminal vesicles. ARCHIVES OF ANDROLOGY 2000; 44:173-86. [PMID: 10864364 DOI: 10.1080/014850100262146] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
SGP-1/prosaposin can be secreted or targeted to the lysosomes where it is processed into smaller saposins (A, B, C, and D) required for the hydrolysis of glycosphingolipids. The deficiency of saposins B and C results in variant forms of metachromatic leukodystrophy and Gaucher's disease, respectively, which are characterized by lysosomal storage of undegraded glycosphingolipids. In the nervous system, prosaposin presents trophic activity. A mouse model was recently developed by creating a null allele in embryonic stem cells through gene targeting to investigate the phenotypic diversity of prosaposin mutations and the involvement of this protein in lysosomal storage diseases, and for the development of therapeutic approaches. Mice homozygous mutants die at the age of 35-40 days and neurological disorders contribute to the early demise of the mutant mice. The male reproductive organs in homozygous mutants show several abnormalities, such as a decrease in testis size with reduced spermiogenesis and an involution of the prostate, seminal vesicles, and epididymis. In these animals, the blood levels of testosterone remain normal. In the prostate of homozygous mutants, only the basal epithelial cells appear to be present, while the secretory cells are absent. These findings suggest that prosaposin may be involved in the development and maintenance of the male reproductive organs, as well as, in cellular differentiation.
Collapse
Affiliation(s)
- C R Morales
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada.
| | | | | | | |
Collapse
|
32
|
Augé N, Nègre-Salvayre A, Salvayre R, Levade T. Sphingomyelin metabolites in vascular cell signaling and atherogenesis. Prog Lipid Res 2000; 39:207-29. [PMID: 10799716 DOI: 10.1016/s0163-7827(00)00007-2] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The atherosclerotic lesion most probably develops through a number of cellular events which implicate all vascular cell types and include synthesis of extracellular proteins, cell proliferation, differentiation and death. Sphingolipids and sphingolipid metabolizing enzymes may play important roles in atherogenesis, not only because of lipoprotein alterations but also by mediating a number of cellular events which are believed to be crucial in the development of the vascular lesions such as proliferation or cell death. Exogenous sphingolipids may mediate various biological effects such as apoptosis, mitogenesis or differentiation depending on the cell type. Moreover, several molecules present in the atherogenic lesion, such as oxidized LDL, growth factors or cytokines, which activate intracellular signaling pathways leading to vascular cell modifications, can stimulate sphingomyelin hydrolysis and generation of ceramide (and other metabolites as sphingosine-1-phosphate). Here we review the potential implication of the sphingomyelin/ceramide cycle in vascular cell signaling related to atherosclerosis, and more generally the role of sphingolipids in the events observed during the atherosclerotic process as cell differentiation, migration, adhesion, retraction, proliferation and death.
Collapse
Affiliation(s)
- N Augé
- Laboratoire de Biochimie, INSERM U. 466, "Maladies Métaboliques," Institut Louis Bugnard, Bât. Université Paul Sabatier, CHU Rangueil, 1 Avenue Jean Poulhès, F-31403, Toulouse, France.
| | | | | | | |
Collapse
|
33
|
The interrelation between the biological functions of sphingolipids and their chemical structure. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2000. [DOI: 10.1007/bf02758855] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
|
34
|
Lansmann S, Bartelsen O, Sandhoff K. Purification and characterization of recombinant human acid sphingomyelinase expressed in insect Sf21 cells. Methods Enzymol 1999; 311:149-56. [PMID: 10563319 DOI: 10.1016/s0076-6879(00)11075-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Affiliation(s)
- S Lansmann
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Germany
| | | | | |
Collapse
|
35
|
Hinkovska-Galcheva VT, Boxer LA, Mansfield PJ, Harsh D, Blackwood A, Shayman JA. The formation of ceramide-1-phosphate during neutrophil phagocytosis and its role in liposome fusion. J Biol Chem 1998; 273:33203-9. [PMID: 9837889 DOI: 10.1074/jbc.273.50.33203] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ceramide, a product of agonist-stimulated sphingomyelinase activation, is known to be generated during the phagocytosis of antibody-coated erythrocytes by polymorphonuclear leukocytes. Agonist-stimulated formation of ceramide-1-phosphate is now shown to occur in 32PO4-labeled neutrophils. Ceramide-1-phosphate is formed by a calcium-dependent ceramide kinase, found predominately in the neutrophil plasma membrane. The neutrophil kinase is specific for ceramide because, in contrast to the bacterial diglyceride kinase, ceramide is not phosphorylated under conditions specific for diglyceride phosphorylation. Conversely, 1,2-diacylglycerol does not serve as substrate for the neutrophil ceramide kinase. Ceramide kinase activation occurs in a time-dependent fashion, reaching peak activity 10 min after formyl peptide stimulation and challenge with antibody-coated erythrocytes. The lipid kinase activity is optimal at pH 6.8. Because the formation of the phagolysosome is a critical event in phagocytosis, the effect of ceramide-1-phosphate in promoting the fusion of liposomes was determined. Both the addition of increasing concentrations of sphingomyelinase D and ceramide-1-phosphate promoted liposomal fusion. In summary, ceramide-1-phosphate is formed during phagocytosis through activation of ceramide kinase. Ceramide-1-phosphate may promote phagolysosome formation.
Collapse
Affiliation(s)
- V T Hinkovska-Galcheva
- Department of Pediatrics, Division of Hematology/Oncology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | | | | | | | | | | |
Collapse
|
36
|
Kwon OS, Newport GD, Slikker W. Quantitative analysis of free sphingoid bases in the brain and spinal cord tissues by high-performance liquid chromatography with a fluorescence detection. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1998; 720:9-14. [PMID: 9892061 DOI: 10.1016/s0378-4347(98)00449-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The o-phthaldialdehyde precolumn derivatives of psychosine, sphinganine and sphingosine extracted from brain and spinal cord tissues were determined by high-performance liquid chromatography-fluorescence detection. This method was developed with the purpose of detecting an endogenous amount of psychosine, sphingosine and sphinganine using small aliquots of brain tissues and spinal cord in rats. These sphingolipid bases were extracted in various ratios of chloroform-methanol and several pH values. Recovery of the method is about 81% in 12 ng/tube (final volume, 320 microl), 90-95% in 45 ng/tube of sphingosine and sphinganine within 2-12% relative standard deviation. Detection limits of these sphingoid bases were about 0.05 pmol/mg brain tissue. In the forebrain, brainstem and spinal cord of rats at three different ages of postnatal days (PND) 1, PND 13 and 6 months old, the endogenous concentrations of psychosine, sphingosine and sphinganine were determined. From these results, this method is suitable for the determination of sphingoid bases in small aliquot of brain and spinal cord tissues.
Collapse
Affiliation(s)
- O S Kwon
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock 72211, USA.
| | | | | |
Collapse
|
37
|
Ghosh N, Sabbadini R, Chatterjee S. Identification, partial purification, and localization of a neutral sphingomyelinase in rabbit skeletal muscle: neutral sphingomyelinase in skeletal muscle. Mol Cell Biochem 1998; 189:161-8. [PMID: 9879667 DOI: 10.1023/a:1006910200656] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We have investigated the presence of neutral sphingomyelinases present in rabbit skeletal muscle fractions. Neutral sphingomyelinase activity measurements and immunoblot analysis of various skeletal muscle fractions indicated that most of the neutral sphingomyelinase was associated with the junctional transverse tubules. Activity gel analysis of the detergent solubilized transverse tubule fraction revealed two distinct bands corresponding to molecular weight on the order of approximately 92 and 53 kDa. Moreover, monospecific antibody raised against pure neutral sphingomyelinase recognized both the 53 and the 92 kDa protein. Peptide mapping studies revealed that both neutral sphingomyelinase isoforms were similar. Moreover, both the enzymes catalyzed the hydrolysis of sphingomyelin to phosphocholine and ceramide. Lithium stimulated and Cu2+ inhibited the activity of both of the enzyme isoforms. However, the 53 kDa isoform was insensitive to activation by Mg2+, and thus differed from the 92 kDa isoform of neutral sphingomyelinase. The localization of neutral sphingomyelinase in skeletal muscle transverse tubule membrane is consistent with transverse tubule production of the sphingomyelin-derived second messenger, sphingosine. Since sphingosine has been shown to modulate calcium release from sarcoplasmic reticulum membranes (Sabbadini et al. (1992) J Biol Chem 207: 15473-15684), our work suggests that neutral sphingomyelinase/sphingosine signaling system may be a physiologically relevant regulator of calcium levels in skeletal muscle.
Collapse
Affiliation(s)
- N Ghosh
- Department of Pediatrics, Johns Hopkins University, School of Medicine, Baltimore, Maryland, USA
| | | | | |
Collapse
|
38
|
Bartelsen O, Lansmann S, Nettersheim M, Lemm T, Ferlinz K, Sandhoff K. Expression of recombinant human acid sphingomyelinase in insect Sf21 cells: purification, processing and enzymatic characterization. J Biotechnol 1998; 63:29-40. [PMID: 9764481 DOI: 10.1016/s0168-1656(98)00070-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Biochemical and structural studies on human acid sphingomyelinase (haSMase) depend on the access to homogeneous biologically active enzyme. Due to the low abundance of native haSMase (n-haSMase) in human tissue, conventional purification strategies are not suitable for the isolation of preparative amounts of the enzyme. We describe a novel approach to the functional expression and purification of haSMase employing the baculovirus expression vector system. Infection of Spodoptera frugiperda 21 cells with recombinant baculovirus encoding haSMase leads to the expression of a glycosylated 75 kDa precursor protein, which is subsequently processed to an enzymatically active secreted 72 kDa haSMase. Variations in N-glycosylation and proteolytic maturation account for the difference in molecular mass between mature recombinant (72 kDa) and human placental haSMase (75 kDa). N-terminal amino acid sequencing of recombinant haSMase (r-haSMase) reveals a 23-residue N-terminal extension compared to the placental enzyme. The apparent K(m) and Vmax values for sphingomyelin degradation by r-haSMase in a micellar assay system are 32 microM and 0.56 mmol h-1 mg-1, respectively. In conclusion, the established baculovirus expression vector system provides an efficient tool for the expression and functional characterization of haSMase.
Collapse
Affiliation(s)
- O Bartelsen
- Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Germany
| | | | | | | | | | | |
Collapse
|
39
|
Suy S, Mitchell JB, Ehleiter D, Haimovitz-Friedman A, Kasid U. Nitroxides tempol and tempo induce divergent signal transduction pathways in MDA-MB 231 breast cancer cells. J Biol Chem 1998; 273:17871-8. [PMID: 9651392 DOI: 10.1074/jbc.273.28.17871] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tempol and tempo are stable free radical nitroxides that possess antioxidant properties. In this study, we examined the effects of these compounds on components of the mitogen-activated protein kinase signal transduction cascade. Tempo treatment (15 min) of MDA-MB 231 human breast cancer cells resulted in significant levels of tyrosine phosphorylation of several as yet unidentified proteins compared with equimolar concentration of tempol (10 mM). Both compounds caused tyrosine phosphorylation and activation of Raf-1 protein kinase (30 min, 2-3-fold). Interestingly, however, only tempol caused increased extracellular signal-regulated kinase 1 activity (2 h, approximately 3-fold). On the other hand, tempo, but not tempol, potently activated stress-activated protein kinase (2 h, >3-fold). Consistent with these data, tempol was found to be noncytotoxic, whereas tempo induced apoptotic cell death (2 h, >50%). Tempo treatment also resulted in significant elevation of ceramide levels at 30 min (54% over control) and 1 h (71% over control) posttreatment, preceding stress-activated protein kinase activation and apoptosis. These data suggest that in the absence of an environmental oxidative stress, tempol and tempo elicit distinct cellular signaling pathways. The recognition of the molecular mechanisms of nitroxide action may have important implications for biological effectiveness of these compounds.
Collapse
Affiliation(s)
- S Suy
- Departments of Radiation Medicine and Biochemistry and Molecular Biology, Lombardi Cancer Center, Georgetown University Medical Center, Washington D.C. 20007, USA
| | | | | | | | | |
Collapse
|
40
|
Ledeen RW, Chakraborty G. Cytokines, signal transduction, and inflammatory demyelination: review and hypothesis. Neurochem Res 1998; 23:277-89. [PMID: 9482240 DOI: 10.1023/a:1022493013904] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The mechanism of focal demyelination in multiple sclerosis has been a long-standing enigma of this disorder. Cytokines, a diverse family of signalling molecules, are viewed as potential mediators of the process based on clinical observations and studies with animal models and tissue/cell culture systems. Myelin and oligodendrocyte (OL) destruction occur in cultured preparations subjected to cytokines such as tumor necrosis factor-alpha (TNF alpha) and lymphotoxin (LT). Many studies have shown these and other cytokines to be elevated at lesion sites and in the CSF of multiple sclerosis (MS) patients, with similar findings in animal models. Some variability in the nature of MS lesion formation has been reported, both OLs and myelin being primary targets. To account for myelin destruction in the presence of apparently functional OLs we hypothesize that cytokines such as TNF alpha and LT alpha contribute to myelin damage through triggering of specific reactions within the myelin sheath. We further propose that neutral sphingomyelinase (SMase) is one such enzyme, two forms of which have been detected in purified myelin. An additional event is accumulation of cholesterol ester, apparently a downstream consequence of cytokine-induced SMase. The resulting lipid changes are viewed as potentially destabilizing to myelin, which may render it more vulnerable to attack by invading and resident phagocytes.
Collapse
Affiliation(s)
- R W Ledeen
- Department of Neurosciences, New Jersey Medical School, UMDNJ, Newark 07103, USA.
| | | |
Collapse
|
41
|
van Echten-Deckert G, Klein A, Linke T, Heinemann T, Weisgerber J, Sandhoff K. Turnover of endogenous ceramide in cultured normal and Farber fibroblasts. J Lipid Res 1997. [DOI: 10.1016/s0022-2275(20)30041-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
42
|
Riboni L, Viani P, Bassi R, Prinetti A, Tettamanti G. The role of sphingolipids in the process of signal transduction. Prog Lipid Res 1997; 36:153-95. [PMID: 9624426 DOI: 10.1016/s0163-7827(97)00008-8] [Citation(s) in RCA: 150] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- L Riboni
- Department of Medical Chemistry and Biochemistry, Medical Faculty, University of Milan, Italy
| | | | | | | | | |
Collapse
|
43
|
Robinson BS, Hii CS, Poulos A, Ferrante A. Activation of neutral sphingomyelinase in human neutrophils by polyunsaturated fatty acids. Immunol Suppl 1997; 91:274-80. [PMID: 9227328 PMCID: PMC1363858 DOI: 10.1046/j.1365-2567.1997.d01-2227.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Although unesterified polyunsaturated fatty acids (PUFA) have been shown to elicit marked changes in neutrophil function, the associated signal transduction processes require clarification. In this study we examined the effect of PUFA on the sphingomyelin (SM)-signalling cycle in human neutrophils. Treatment of neutrophils with eicosatetraenoic acid [arachidonic acid, 20:4(n-6)] caused a decrease in the mass of cellular SM and an increase in the level of ceramide. 20:4(n-6)-stimulated neutral sphingomyelinase (SMase) activity of the leucocytes in a time- and concentration-dependent manner. Other unsaturated fatty acids, docosahexaenoic [22:6(n-3)], eicosapentaenoic [20:5(n-3)], octadecenoic [oleic, 18:1(n-9)] and octadecadienoic [linoleic, 18:2(n-6)] acids also had the capacity to activate neutral SMase; however, certain 20:4(n-6) derivatives ¿20:4(n-6) methyl ester [20:4(n-6)ME], 15-hydroperoxyeicosatetraenoic (15-HPETE) and 15-hydroxyeicosatetraenoic (15-HETE) acids¿, very-long-chain PUFA ¿tetracosatetraenoic [24:4(n-6)] and octacosatetraenoic [28:4(n-6)] acids¿ and saturated fatty acids [octadecanoic (stearic, 18:0) and eicosanoic (arachidic, 20:0) acids] had no significant effect. Activation of neutral SMase by 20:4(n-6) appeared to involve metabolism via 20:4(n-6)CoA (arachidonoyl CoA) and was not dependent on prostaglandin and leukotriene synthesis. All of the fatty acids and derivatives tested failed to activate acidic SMase of neutrophils. Ceramide was found to inhibit 20:4(n-6)-induced superoxide generation by the cells. It is envisaged that the PUFA-induced ceramide production in neutrophils plays a role in the regulation of biological responses.
Collapse
Affiliation(s)
- B S Robinson
- Department of Immunopathology, Women's and Children's Hospital, North Adelaide, Australia
| | | | | | | |
Collapse
|
44
|
Abstract
Sphingolipids (SLs) are important structural and regulatory components of neuronal plasma membranes. Previous studies using fumonisin B1, an inhibitor of the synthesis of ceramide, the precursor of all SLs, demonstrated that ceramide synthesis is required to sustain axonal growth in hippocampal neurons (; ) and dendritic growth in cerebellar Purkinje cells (). We now show that ceramide plays distinct roles at different stages of neuronal development. (1) During axon growth, ceramide must be metabolized to glucosylceramide (GlcCer) to sustain growth. Thus, whereas D-erythro-ceramide, which is metabolized to GlcCer, is able to antagonize the disruptive effects of fumonisin B1 on axon growth, L-threo-ceramide, which is not metabolized to GlcCer, is ineffective. (2) The formation of minor processes from lamellipodia can be stimulated by incubation with short-acyl chain analogs of ceramide that are active in ceramide-mediated signaling pathways, or by generation of endogenous ceramide by incubation with sphingomyelinase. However, GlcCer synthesis is not required for this initial stage of neuronal development. (3) During minor process formation and during axon growth, incubation with high concentrations of ceramide or sphingomyelinase, but not dihydroceramide, induces apoptosis. Together, these observations are consistent with the possibility that minor process formation and apoptosis can be regulated by ceramide-dependent signaling pathways and that the decision whether to enter these diametrically opposed pathways depends on intracellular ceramide concentrations. In contrast, axonal growth requires the synthesis of GlcCer from ceramide, perhaps to support an intracellular transport pathway.
Collapse
|
45
|
Ink B, Zörnig M, Baum B, Hajibagheri N, James C, Chittenden T, Evan G. Human Bak induces cell death in Schizosaccharomyces pombe with morphological changes similar to those with apoptosis in mammalian cells. Mol Cell Biol 1997; 17:2468-74. [PMID: 9111315 PMCID: PMC232095 DOI: 10.1128/mcb.17.5.2468] [Citation(s) in RCA: 105] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Apoptosis as a form of programmed cell death (PCD) in multicellular organisms is a well-established genetically controlled process that leads to elimination of unnecessary or damaged cells. Recently, PCD has also been described for unicellular organisms as a process for the socially advantageous regulation of cell survival. The human Bcl-2 family member Bak induces apoptosis in mammalian cells which is counteracted by the Bcl-x(L) protein. We show that Bak also kills the unicellular fission yeast Schizosaccharomyces pombe and that this is inhibited by coexpression of human Bcl-x(L). Moreover, the same critical BH3 domain of Bak that is required for induction of apoptosis in mammalian cells is also required for inducing death in yeast. This suggests that Bak kills mammalian and yeast cells by similar mechanisms. The phenotype of the Bak-induced death in yeast involves condensation and fragmentation of the chromatin as well as dissolution of the nuclear envelope, all of which are features of mammalian apoptosis. These data suggest that the evolutionarily conserved metazoan PCD pathway is also present in unicellular yeast.
Collapse
Affiliation(s)
- B Ink
- Imperial Cancer Research Fund Laboratories, London, United Kingdom
| | | | | | | | | | | | | |
Collapse
|
46
|
Limatola C, Barabino B, Nista A, Santoni A. Interleukin 1-beta-induced protein kinase C-zeta activation is mimicked by exogenous phospholipase D. Biochem J 1997; 321 ( Pt 2):497-501. [PMID: 9020886 PMCID: PMC1218096 DOI: 10.1042/bj3210497] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Interleukin 1-beta (IL1-beta) is a pleiotropic cytokine that stimulates a number of signal transduction pathways in cells, leading to different cellular responses. In this study we investigated the signal transduction pathways activated by IL1-beta in two different human cell lines: RD/TE671, a rhabdomyosarcoma, and EJ, a bladder-derived carcinoma. We showed that this cytokine induced the activation of protein kinase C-zeta (PKC-zeta) and the accumulation of a putative physiological PKC-zeta activator, phosphatidic acid [Limatola, Schaap, Moolenaar and van Blitterswijk (1994) Biochem. J. 304, 1001-1008]. Exogenously supplied phospholipase D, which generated cellular phosphatidic acid, was able to mimic the cytokine effect, supporting the hypothesis that this lipid second messenger might contribute to cytokine-induced PKC-zeta activation. In addition, we show that IL1-beta stimulation of BOSC23 cells, transiently overexpressing PKC-zeta, induced an increase in PKC-zeta autophosphorylation. These results give the first direct evidence that IL1-beta can activate this atypical PKC isoform and suggest that this enzyme might be involved in mediating some of the biological effects induced by IL1-beta.
Collapse
Affiliation(s)
- C Limatola
- Biophysics Laboratory, Centro Ricerca Sperimentale IRE, Rome, Italy
| | | | | | | |
Collapse
|
47
|
Ferlinz K, Hurwitz R, Moczall H, Lansmann S, Schuchman EH, Sandhoff K. Functional characterization of the N-glycosylation sites of human acid sphingomyelinase by site-directed mutagenesis. EUROPEAN JOURNAL OF BIOCHEMISTRY 1997; 243:511-7. [PMID: 9030779 DOI: 10.1111/j.1432-1033.1997.511_1a.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Most soluble lysosomal enzymes require a mannose-6-phosphate recognition marker present on asparagine-linked oligosaccharides for proper targeting to lysosomes. We have determined the influence of the six potential N-linked oligosaccharide chains of human acid sphingomyelinase (ASM) on catalytic activity, targeting, and processing of the enzyme. Each N-glycosylation site was modified by site-directed mutagenesis and subsequently expressed in COS-1 cells. Evidence is presented that five of these sites are used. Elimination of the four N-terminal glycosylation sites does not disturb lysosomal targeting, processing, or enzymatic activity. However, removal of the two C-terminal N-glycosylation sites inhibits the formation of mature enzyme. Absence of glycosylation site five resulted in rapid cleavage of the primary translation product to an enzymatically inactive protein which accumulated inside the endoplasmic reticulum/Golgi, whereas deletion of glycosylation site six led to the formation of an inactive ASM precursor, also retained inside the endoplasmic reticulum/Golgi. Our results also provide evidence that the site of early proteolytic cleavage of newly synthesized ASM must be located between the second and third glycosylation sites.
Collapse
Affiliation(s)
- K Ferlinz
- Institut für Organische Chemie und Biochemie, Bonn, Germany
| | | | | | | | | | | |
Collapse
|
48
|
Matsuo Y, Yamada A, Tsukamoto K, Tamura H, Ikezawa H, Nakamura H, Nishikawa K. A distant evolutionary relationship between bacterial sphingomyelinase and mammalian DNase I. Protein Sci 1996; 5:2459-67. [PMID: 8976554 PMCID: PMC2143316 DOI: 10.1002/pro.5560051208] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The three-dimensional structure of bacterial sphingomyelinase (SMase) was predicted using a protein fold recognition method; the search of a library of known structures showed that the SMase sequence is highly compatible with the mammalian DNase I structure, which suggested that SMase adopts a structure similar to that of DNase I. The amino acid sequence alignment based on the prediction revealed that, despite the lack of overall sequence similarity (less than 10% identity), those residues of DNase I that are involved in the hydrolysis of the phosphodiester bond, including two histidine residues (His 134 and His 252) of the active center, are conserved in SMase. In addition, a conserved pentapeptide sequence motif was found, which includes two catalytically critical residues, Asp 251 and His 252. A sequence database search showed that the motif is highly specific to mammalian DNase I and bacterial SMase. The functional roles of SMase residues identified by the sequence comparison were consistent with the results from mutant studies. Two Bacillus cereus SMase mutants (H134A and H252A) were constructed by site-directed mutagenesis. They completely abolished their catalytic activity. A model for the SMase-sphingomyelin complex structure was built to investigate how the SMase specifically recognizes its substrate. The model suggested that a set of residues conserved among bacterial SMases, including Trp 28 and Phe 55, might be important in the substrate recognition. The predicted structural similarity and the conservation of the functionally important residues strongly suggest a distant evolutionary relationship between bacterial SMase and mammalian DNase I. These two phosphodiesterases must have acquired the specificity for different substrates in the course of evolution.
Collapse
Affiliation(s)
- Y Matsuo
- Protein Engineering Research Institute, Osaka, Japan
| | | | | | | | | | | | | |
Collapse
|
49
|
Tettamanti G, Prinetti A, Bassi R, Viani P, Giussani P, Riboni L. Sphingoid bioregulators in the differentiation of cells of neural origin. JOURNAL OF LIPID MEDIATORS AND CELL SIGNALLING 1996; 14:263-75. [PMID: 8906572 DOI: 10.1016/0929-7855(96)00535-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The involvement of ceramide in the differentiation of two neuroblastoma cell lines, Neuro2a and SH-SY5Y, and cerebellar granule cells in primary culture was investigated. The following results were obtained: (a) the cellular content of ceramide markedly increased with induced differentiation of Neuro2a cells (inducers: RA, FCS deprivation), SH-SY5Y cells (inducers: RA, PMA), and spontaneous differentiation of cerebellar granule cells; (b) all the investigated cells in the differentiated form displayed a higher ability to produce ceramide from exogenously administered [3H]Sph-SM and expressed a higher content of neutral sphingomyelinase and, in the case of cerebellar granule cells, also of acidic sphingomyelinase; (c) inhibition of ceramide biosynthesis by Fumonisin B1 blocked the process of differentiation in Neuro2a and cerebellar granule cells; and (d) treatments capable of enhancing ceramide level (administration of sphingosine or C2-Ceramide) induced differentiation in both Neuro2a and SH-SY5Y cells. The data obtained support the notion that ceramide plays a general biomodulatory role in neural cell differentiation.
Collapse
Affiliation(s)
- G Tettamanti
- Department of Medical Chemistry and Biochemistry, University of Milan, Italy.
| | | | | | | | | | | |
Collapse
|
50
|
Reyes JG, Robayna IG, Delgado PS, González IH, Aguiar JQ, Rosas FE, Fanjul LF, Galarreta CM. c-Jun is a downstream target for ceramide-activated protein phosphatase in A431 cells. J Biol Chem 1996; 271:21375-80. [PMID: 8702918 DOI: 10.1074/jbc.271.35.21375] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Stimulation of [3H]serine-labeled A431 cells with tumor necrosis factor-alpha (TNFalpha) or bacterial sphingomyelinase (SMase) resulted in a rapid decrease (approximately 50% by 15 min) in cellular [3H]sphingomyelin content and generation of the lipid moiety [3H]ceramide, which remained elevated 60 min later. Sphingomyelin hydrolysis in response to TNFalpha or bacterial SMase resulted in a time-dependent decrease in the phosphorylation state of c-Jun protein, an effect that was also observed in cells treated with the membrane-permeable ceramide analogue N-hexanoylsphingosine (C6-ceramide). The rapid dephosphorylation of the c-Jun gene product in response to TNFalpha, SMase, or C6-ceramide was not observed in A431 cells treated with the serine-threonine phosphatase inhibitor okadaic acid. After the initial steps of previously described methods for the purification of a ceramide-activated protein phosphatase termed CAPP (Dobrowsky, R. T., Kamibayashi, C., Mumby, M. C., and Hannun, Y. A. (1993) J. Biol. Chem. 268, 15523-15530), we obtained a cytosolic fraction from A431 cells that specifically dephosphorylated 32Pi-labeled c-Jun protein used as substrate in an immunocomplex phosphatase assay. Phosphatase activity in vitro was apparent only in the presence of ceramide (5 micro) and was specifically abrogated when okadaic acid (1 n) was included in the immunocomplex phosphatase assay. These results provide strong evidence for c-Jun as a downstream target for CAPP activated in response to post-TNF signaling in A431 cells.
Collapse
Affiliation(s)
- J G Reyes
- Departamento de Endocrinología Celular y Molecular, Universidad de Las Palmas, School of Medicine, Las Palmas 35016, Spain
| | | | | | | | | | | | | | | |
Collapse
|