1
|
Chandrasegaran S, Sluka JP, Shanley D. Modelling the spatiotemporal dynamics of senescent cells in wound healing, chronic wounds, and fibrosis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.04.602041. [PMID: 39026713 PMCID: PMC11257496 DOI: 10.1101/2024.07.04.602041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Cellular senescence is known to drive age-related pathology through the senescence-associated secretory phenotype (SASP). However, it also plays important physiological roles such as cancer suppression, embryogenesis and wound healing. Wound healing is a tightly regulated process which when disrupted results in conditions such as fibrosis and chronic wounds. Senescent cells appear during the proliferation phase of the healing process where the SASP is involved in maintaining tissue homeostasis after damage. Interestingly, SASP composition and functionality was recently found to be temporally regulated, with distinct SASP profiles involved: a fibrogenic, followed by a fibrolytic SASP, which could have important implications for the role of senescent cells in wound healing. Given the number of factors at play a full understanding requires addressing the multiple levels of complexity, pertaining to the various cell behaviours, individually followed by investigating the interactions and influence each of these elements have on each other and the system as a whole. Here, a systems biology approach was adopted whereby a multi-scale model of wound healing that includes the dynamics of senescent cell behaviour and corresponding SASP composition within the wound microenvironment was developed. The model was built using the software CompuCell3D, which is based on a Cellular Potts modelling framework. We used an existing body of data on healthy wound healing to calibrate the model and validation was done on known disease conditions. The model provides understanding of the spatiotemporal dynamics of different senescent cell phenotypes and the roles they play within the wound healing process. The model also shows how an overall disruption of tissue-level coordination due to age-related changes results in different disease states including fibrosis and chronic wounds. Further specific data to increase model confidence could be used to explore senolytic treatments in wound disorders.
Collapse
Affiliation(s)
- Sharmilla Chandrasegaran
- Campus for Ageing and Vitality, Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | - James P Sluka
- Department of Intelligent Systems Engineering and Biocomplexity Institute, Indiana University Bloomington, Bloomington, IN, USA
| | - Daryl Shanley
- Campus for Ageing and Vitality, Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| |
Collapse
|
2
|
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
|
3
|
Mechanistic target of rapamycin complex 1 orchestrates the interplay between hepatocytes and Kupffer cells to determine the outcome of immune-mediated hepatitis. Cell Death Dis 2022; 13:1031. [PMID: 36494334 PMCID: PMC9734196 DOI: 10.1038/s41419-022-05487-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 11/30/2022] [Accepted: 11/30/2022] [Indexed: 12/13/2022]
Abstract
The cell-cell interaction between hepatocytes and Kupffer cells (KCs) is crucial for maintaining liver homeostasis, and the loss of KCs and hepatocytes is known to represent a common pathogenic phenomenon in autoimmune hepatitis. Until now, the mechanisms of cell-cell interaction between hepatocytes and KCs involved in immune-mediated hepatitis remains unclear. Here we dissected the impact of activated mTORC1 on the cell-cell interaction of KCs and hepatocyte in immune-mediated hepatitis. In the liver from patients with AIH and mice administrated with Con-A, mTORC1 was activated in both KCs and hepatocytes. The activated mTORC1 signal in hepatocytes with Con-A challenge caused a markedly production of miR-329-3p. Upregulated miR-329-3p inhibited SGMS1 expression in KCs through paracrine, resulting in the death of KCs. Most of maintained KCs were p-S6 positive and distributed in hepatocyte mTORC1 negative area. The activation of mTORC1 enabled KCs expressed complement factor B (CFB) to enhance the complement alternative system, which produced more complement factors to aggravate liver injury. Our findings remonstrate a heterogeneous role of mTORC1 in specific cell type for maintaining tolerogenic liver environment, and will form the basis for the development of new interventions against immune-mediated hepatitis.
Collapse
|
4
|
Guo J, Feng J, Qu H, Xu H, Zhou H. Potential Drug Targets for Ceramide Metabolism in Cardiovascular Disease. J Cardiovasc Dev Dis 2022; 9:jcdd9120434. [PMID: 36547431 PMCID: PMC9782850 DOI: 10.3390/jcdd9120434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 11/28/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022] Open
Abstract
Cardiovascular disease poses a significant threat to the quality of human life. Metabolic abnormalities caused by excessive caloric intake have been shown to lead to the development of cardiovascular diseases. Ceramides are structural molecules found in biological membranes; they are crucial for cell survival and lipid metabolism, as they maintain barrier function and membrane fluidity. Increasing evidence has demonstrated that ceramide has a strong correlation with cardiovascular disease progression. Nevertheless, it remains a challenge to develop sphingolipids as therapeutic targets to improve the prognosis of cardiovascular diseases. In this review, we summarize the three synthesis pathways of ceramide and other intermediates that are important in ceramide metabolism. Furthermore, mechanistic studies and therapeutic strategies, including clinical drugs and bioactive molecules based on these intermediates, are discussed.
Collapse
Affiliation(s)
- Jiaying Guo
- Institute of Cardiovascular Disease of Integrated Traditional Chinese and Western Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, No. 528, Zhangheng Road, Shanghai 201203, China
| | - Jiling Feng
- Institute of Cardiovascular Disease of Integrated Traditional Chinese and Western Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, No. 528, Zhangheng Road, Shanghai 201203, China
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, No. 1200, Cailun Road, Shanghai 201203, China
- Engineering Research Center of Shanghai Colleges for TCM New Drug Discovery, No. 1200, Cailun Road, Shanghai 201203, China
| | - Huiyan Qu
- Institute of Cardiovascular Disease of Integrated Traditional Chinese and Western Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, No. 528, Zhangheng Road, Shanghai 201203, China
| | - Hongxi Xu
- Institute of Cardiovascular Disease of Integrated Traditional Chinese and Western Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, No. 528, Zhangheng Road, Shanghai 201203, China
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, No. 1200, Cailun Road, Shanghai 201203, China
- Engineering Research Center of Shanghai Colleges for TCM New Drug Discovery, No. 1200, Cailun Road, Shanghai 201203, China
- Correspondence: (H.X.); (H.Z.); Tel.: +86-021-5132-3089 (H.X.); +86-021-2025-6770 (H.Z.)
| | - Hua Zhou
- Institute of Cardiovascular Disease of Integrated Traditional Chinese and Western Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, No. 528, Zhangheng Road, Shanghai 201203, China
- Correspondence: (H.X.); (H.Z.); Tel.: +86-021-5132-3089 (H.X.); +86-021-2025-6770 (H.Z.)
| |
Collapse
|
5
|
Jarai BM, Fromen CA. Nanoparticle Internalization Promotes the Survival of Primary Macrophages. ADVANCED NANOBIOMED RESEARCH 2022; 2. [PMID: 35991157 PMCID: PMC9387674 DOI: 10.1002/anbr.202100127] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Macrophages, a class of tissue resident innate immune cells, are responsible for sequestering foreign objects through the process of phagocytosis, making them a promising target for immune-modulation via particulate engineering. Here, we report that nanoparticle (NP) dosing and cellular internalization via phagocytosis significantly enhances survival of ex vivo cultures of primary bone marrow-derived, alveolar, and peritoneal macrophages over particle-free controls. The enhanced survival is attributed to suppression of caspase-dependent apoptosis and is linked to phagocytosis and lysosomal signaling. Uniquely, poly(ethylene glycol)-based NP treatment extended cell viability in the absence of macrophage polarization and enhanced expression of pro-survival B cell lymphoma-2 (Bcl-2) protein in macrophages following multiple routes of in vivo administration. The enhanced survival phenomenon is also applicable to NPs of alternative chemistries, indicating the potential universality of this phenomenon with relevant drug delivery particles. These findings provide a framework for extending the lifespan of primary macrophages ex vivo for drug screening, vaccine studies, and cell therapies and has implications for any in vivo particulate immune-engineering applications.
Collapse
Affiliation(s)
- Bader M. Jarai
- Department of Chemical and Biomolecular Engineering University of Delaware 150 Academy St. Newark DE 19716 USA
| | - Catherine A. Fromen
- Department of Chemical and Biomolecular Engineering University of Delaware 150 Academy St. Newark DE 19716 USA
| |
Collapse
|
6
|
Johnston JM, Angyal A, Bauer RC, Hamby S, Suvarna SK, Baidžajevas K, Hegedus Z, Dear TN, Turner M, Wilson HL, Goodall AH, Rader DJ, Shoulders CC, Francis SE, Kiss-Toth E. Myeloid Tribbles 1 induces early atherosclerosis via enhanced foam cell expansion. SCIENCE ADVANCES 2019; 5:eaax9183. [PMID: 31692955 PMCID: PMC6821468 DOI: 10.1126/sciadv.aax9183] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 09/14/2019] [Indexed: 05/16/2023]
Abstract
Macrophages drive atherosclerotic plaque progression and rupture; hence, attenuating their atherosclerosis-inducing properties holds promise for reducing coronary heart disease (CHD). Recent studies in mouse models have demonstrated that Tribbles 1 (Trib1) regulates macrophage phenotype and shows that Trib1 deficiency increases plasma cholesterol and triglyceride levels, suggesting that reduced TRIB1 expression mediates the strong genetic association between the TRIB1 locus and increased CHD risk in man. However, we report here that myeloid-specific Trib1 (mTrib1) deficiency reduces early atheroma formation and that mTrib1 transgene expression increases atherogenesis. Mechanistically, mTrib1 increased macrophage lipid accumulation and the expression of a critical receptor (OLR1), promoting oxidized low-density lipoprotein uptake and the formation of lipid-laden foam cells. As TRIB1 and OLR1 RNA levels were also strongly correlated in human macrophages, we suggest that a conserved, TRIB1-mediated mechanism drives foam cell formation in atherosclerotic plaque and that inhibiting mTRIB1 could be used therapeutically to reduce CHD.
Collapse
Affiliation(s)
- Jessica M. Johnston
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK
| | - Adrienn Angyal
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK
| | - Robert C. Bauer
- Division of Cardiology, Department of Medicine, Columbia University Medical Center, New York, NY 10032, USA
- Perelman School of Medicine at the University of Pennsylvania and Children’s Hospital of Philadelphia, Philadelphia, PA 19104-5158, USA
| | - Stephen Hamby
- Department of Cardiovascular Sciences, University of Leicester and NIHR Cardiovascular Biomedical Research Unit, Glenfield Hospital, Leicester, UK
| | - S. Kim Suvarna
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK
| | - Kajus Baidžajevas
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK
| | - Zoltan Hegedus
- Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Temesvari korut 62, Szeged H-6726, Hungary
- Departments of Biochemistry and Medical Chemistry, University of Pecs, Medical School, Szigeti ut 12, Pecs H-7624, Hungary
| | - T. Neil Dear
- Division of Biomedical Services, University of Leicester, Leicester, UK
| | - Martin Turner
- Laboratory of Lymphocyte Signalling and Development, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | | | - Heather L. Wilson
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK
| | - Alison H. Goodall
- Department of Cardiovascular Sciences, University of Leicester and NIHR Cardiovascular Biomedical Research Unit, Glenfield Hospital, Leicester, UK
| | - Daniel J. Rader
- Perelman School of Medicine at the University of Pennsylvania and Children’s Hospital of Philadelphia, Philadelphia, PA 19104-5158, USA
| | - Carol C. Shoulders
- Centre for Endocrinology, William Harvey Research Institute, Queen Mary University of London and the Barts and the London School of Medicine and Dentistry, London EC1M 6BQ, UK
| | - Sheila E. Francis
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK
| | - Endre Kiss-Toth
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK
| |
Collapse
|
7
|
He X, Wang L, Chen XF, Liang Q, Wang WQ, Lin AQ, Yi L, Wang Y, Gao Q. Metformin improved oxidized low-density lipoprotein-impaired mitochondrial function and increased glucose uptake involving Akt-AS160 pathway in raw264.7 macrophages. Chin Med J (Engl) 2019; 132:1713-1722. [PMID: 31268904 PMCID: PMC6759109 DOI: 10.1097/cm9.0000000000000333] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Macrophage accumulation in the vascular wall is a hallmark of atherosclerosis. Studies showed that shifting of oxidized lipids-induced inflammatory macrophages towards an anti-inflammatory phenotype by promoting oxidative metabolism attenuated atherosclerosis progression. Therefore, this study aimed to investigate whether metformin, which has ameliorated atherosclerosis in animal models and clinical trials, modulated oxidized low-density lipoprotein (Ox-LDL) induced inflammatory status in macrophages by regulating cellular oxidative metabolism. METHODS Murine raw264.7 macrophages were incubated with Ox-LDL (50 μg/mL) in the presence or absence of metformin (15 μmol/L) for 24 h. Real-time polymerase chain reaction was used to quantify the transcription of classically activated (M1) pro-inflammatory and alternatively activated (M2) anti-inflammatory markers and mitochondrial DNA copy numbers. Cellular reactive oxygen species (ROS) production and mitochondrial membrane potential were detected by immunofluorescence. Cellular adenosine triphosphate (ATP) synthesis, glucose uptake, and lactic acid production were measured by commercial kit and normalized to cellular lysates. Western blotting analysis was performed to detect the expression of mitochondrial fusion/fission related proteins, enzymes mediating lipid metabolism and signaling pathway of glucose transport. Differences between groups were analyzed using one-way analysis of variance. RESULTS Metformin improved Ox-LDL-impaired anti-inflammatory phenotype in raw264.7 macrophages as shown by up-regulated transcription of anti-inflammatory markers including interleukin 10 (0.76 ± 0.04 vs. 0.94 ± 0.01, P = 0.003) and Resistin-like molecule alpha (0.67 ± 0.08 vs. 1.78 ± 0.34, P = 0.030). Conversely, Ox-LDL-diminished phosphorylation of Akt was up-regulated by metformin treatment (0.47 ± 0.05 vs. 1.02 ± 0.08, P = 0.040), associated with an improvement of mitochondrial function, characterized by decreased ROS generation (2.50 ± 0.07 vs. 2.15 ± 0.04, P = 0.040), increased lipid oxidation, and elevated cellular ATP production (0.026 ± 0.001 vs. 0.035 ± 0.003, P = 0.020). Moreover, metformin-mediated Akt activation increased Akt substrate of 160 kDa (AS160) phosphorylation (0.51 ± 0.04 vs. 1.03 ± 0.03, P = 0.0041), promoted membrane translocation of glucose transporter 1, and increased glucose influx into the cells (4.78 ± 0.04 vs. 5.47 ± 0.01, P < 0.001). CONCLUSION This study suggested that targeting macrophage metabolism with new or existing drugs had therapeutic potential for the prevention and treatment of diabetes-accelerated atherosclerosis.
Collapse
Affiliation(s)
- Xuan He
- Medical School of Nanjing University, Nanjing, Jiangsu 210093, China
| | - Lei Wang
- Medical School of Nanjing University, Nanjing, Jiangsu 210093, China
| | - Xiu-Fang Chen
- Department of Biochemistry, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Qiao Liang
- Medical School of Nanjing University, Nanjing, Jiangsu 210093, China
| | - Wen-Qing Wang
- Medical School of Nanjing University, Nanjing, Jiangsu 210093, China
| | - An-Qi Lin
- Medical School of Nanjing University, Nanjing, Jiangsu 210093, China
| | - Long Yi
- Medical School of Nanjing University, Nanjing, Jiangsu 210093, China
| | - Yong Wang
- Medical School of Nanjing University, Nanjing, Jiangsu 210093, China
| | - Qian Gao
- Medical School of Nanjing University, Nanjing, Jiangsu 210093, China
| |
Collapse
|
8
|
Lopes-Virella MF, Virella G. Modified LDL Immune Complexes and Cardiovascular Disease. Curr Med Chem 2019; 26:1680-1692. [DOI: 10.2174/0929867325666180524114429] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 11/17/2017] [Accepted: 12/28/2017] [Indexed: 12/17/2022]
Abstract
Modified forms of LDL, both spontaneously formed in the organism or prepared in the laboratory, are immunogenic. As a consequence, antigen-antibody complexes (immune complexes, IC) formed in vivo can be measured in the peripheral blood, and their levels are strong predictors of cardiovascular disease (CVD). It has been possible to generate antibodies that recognize different LDL modifications, allowing the analysis of circulating IC constitution. Clinical studies showed that the antigenic constitution of the IC has a modulating effect on the development of CVD. Patients whose IC react strongly with antibodies to copper oxidized LDL (oxLDL) show progressive development of atherosclerosis as demonstrated by increased intima–media thickness and increased coronary calcification scores. In contrast, patients whose IC react strongly with antibodies to the heavily oxidized malondialdehyde LDL prepared in vitro (MDA-LDL) are at a high risk of acute vascular events, mainly myocardial infarction. In vitro studies have shown that while oxLDL IC induce both cell proliferation and mild to moderate macrophage apoptosis, MDA-LDL IC induce a more marked macrophage apoptosis but not cell proliferation. In addition, MDA-LDL IC induce the release of higher levels of matrix metalloproteinases and TNF than oxLDL IC. High levels of TNF are likely to be a major factor leading to apoptosis and high levels of metalloproteinases are likely to play a role in the thinning of the fibrous cap of the atheromatous plaque. The combination of apoptosis and fibrous cap thinning is a well-known characteristic of vulnerable plaques, which are more prone to rupture and responsible for the majority of acute cardiovascular events.
Collapse
Affiliation(s)
- Maria F. Lopes-Virella
- Department of Medicine, Medical University of South Carolina, Charleston, SC, USA; Ralph A. Johnson VA Medical Center, Charleston, SC, United States
| | - Gabriel Virella
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC, United States
| |
Collapse
|
9
|
Albeituni S, Stiban J. Roles of Ceramides and Other Sphingolipids in Immune Cell Function and Inflammation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1161:169-191. [PMID: 31562630 DOI: 10.1007/978-3-030-21735-8_15] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Ceramides are bioactive sphingolipids that support the structure of the plasma membrane and mediate numerous cell-signaling events in eukaryotic cells. The finding that ceramides act as second messengers transducing cellular signals has attracted substantial attention in several fields of Biology. Since all cells contain lipid plasma membranes, the impact of various ceramides, ceramide synthases, ceramide metabolites, and other sphingolipids has been implicated in a vast range of cellular functions including, migration, proliferation, response to external stimuli, and death. The roles of lipids in these functions widely differ among the diverse cell types. Herein, we discuss the roles of ceramides and other sphingolipids in mediating the function of various immune cells; particularly dendritic cells, neutrophils, and macrophages. In addition, we highlight the main studies describing effects of ceramides in inflammation, specifically in various inflammatory settings including insulin resistance, graft-versus-host disease, immune suppression in cancer, multiple sclerosis, and inflammatory bowel disease.
Collapse
Affiliation(s)
- Sabrin Albeituni
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Johnny Stiban
- Department of Biology and Biochemistry, Birzeit University, West Bank, Palestine.
| |
Collapse
|
10
|
Abstract
Ceramide 1-phosphate (C1P) is a pleiotropic bioactive sphingolipid metabolite capable of regulating key physiologic cell functions and promoting pathologic processes. Concerning pathology, C1P or ceramide kinase (CerK), the enzyme responsible for its biosynthesis in mammalian cells, has been implicated in cancer cell growth, survival, and dissemination and is involved in inflammatory responses associated with different types of cancer cells. The mechanisms or signaling pathways mediating these C1P actions have only been partially described. This chapter reviews recent progress in identifying signal transduction pathways involved in the promotion of cancer cell growth, survival, and dissemination by CerK and C1P.
Collapse
Affiliation(s)
- Antonio Gomez-Muñoz
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| |
Collapse
|
11
|
Immune complexes containing malondialdehyde (MDA) LDL induce apoptosis in human macrophages. Clin Immunol 2018; 187:1-9. [DOI: 10.1016/j.clim.2017.06.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 06/27/2017] [Accepted: 06/27/2017] [Indexed: 11/22/2022]
|
12
|
Ouro A, Arana L, Riazy M, Zhang P, Gomez-Larrauri A, Steinbrecher U, Duronio V, Gomez-Muñoz A. Vascular endothelial growth factor mediates ceramide 1-phosphate-stimulated macrophage proliferation. Exp Cell Res 2017; 361:277-283. [PMID: 29080796 DOI: 10.1016/j.yexcr.2017.10.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2017] [Revised: 10/07/2017] [Accepted: 10/24/2017] [Indexed: 12/12/2022]
Abstract
The bioactive sphingolipid ceramide 1-phosphate (C1P) regulates cell division in a variety of cell types including macrophages. However, the mechanisms involved in this action are not completely understood. In the present work we show that C1P stimulates the release of vascular endothelial growth factor (VEGF) in RAW264.7 macrophages, and that this growth factor is essential for stimulation of cell proliferation by C1P. The stimulation of VEGF release was dependent upon activation of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (PKB-1 also known as Akt-1), and mitogen-activated protein kinase-kinase (MEK)/extracellularly regulated kinase-2 (ERK-2) pathways, as inhibition of these kinases with selective pharmacological inhibitors or with specific gene silencing siRNA, abrogated VEGF release. A key observation was that sequestration of VEGF with a neutralizing antibody, or treatment with VEGF siRNA abolished C1P-stimulated macrophage growth. Also, inhibition of the pathways involved in C1P-stimulated VEGF release inhibited the stimulation of macrophage growth by C1P. Moreover, blockade of VEGF receptor-2 (VEGFR-2), which is the primary receptor for VEGF, with the pharmacological inhibitor DMH4, or with specific VEGFR-2 siRNA, substantially inhibited C1P-stimulated cell growth. It can be concluded that stimulation of VEGF release is a key factor in the promotion of macrophage proliferation by C1P.
Collapse
Affiliation(s)
- Alberto Ouro
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), 48080 Bilbao, Spain
| | - Lide Arana
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), 48080 Bilbao, Spain
| | - Maziar Riazy
- Department of Medicine. University of British Columbia and Vancouver Coastal Health Research Institute, Vancouver, British Columbia, Canada
| | - Peng Zhang
- Department of Medicine. University of British Columbia and Vancouver Coastal Health Research Institute, Vancouver, British Columbia, Canada
| | - Ana Gomez-Larrauri
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), 48080 Bilbao, Spain
| | - Urs Steinbrecher
- Department of Medicine. University of British Columbia and Vancouver Coastal Health Research Institute, Vancouver, British Columbia, Canada
| | - Vincent Duronio
- Department of Medicine. University of British Columbia and Vancouver Coastal Health Research Institute, Vancouver, British Columbia, Canada
| | - Antonio Gomez-Muñoz
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), 48080 Bilbao, Spain.
| |
Collapse
|
13
|
De Giorgi M, Enjyoji K, Jiang G, Csizmadia E, Mitsuhashi S, Gumina RJ, Smolenski RT, Robson SC. Complete deletion of Cd39 is atheroprotective in apolipoprotein E-deficient mice. J Lipid Res 2017; 58:1292-1305. [PMID: 28487312 PMCID: PMC5496028 DOI: 10.1194/jlr.m072132] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 04/28/2017] [Indexed: 02/07/2023] Open
Abstract
Cd39 scavenges extracellular ATP and ADP, ultimately generating adenosine, a nucleoside, which has anti-inflammatory effects in the vasculature. We have evaluated the role of Cd39 in the development of atherosclerosis in hyperlipidemic mice. ApoE KO (Cd39+/+/ApoE−/−) and Cd39/ApoE double KO (DKO) (Cd39−/−/ApoE−/−) mice were maintained on chow or Western diet for up to 20 weeks before evaluation of atherosclerotic lesions. We found that DKO mice exhibited significantly fewer atherosclerotic lesions than ApoE KO mice, irrespective of diet. Analyses of plaque composition revealed diminished foam cells in the fatty streaks and smaller necrotic cores in advanced lesions of DKO mice, when compared with those in ApoE KO mice. This atheroprotective phenotype was associated with impaired platelet reactivity to ADP in vitro and prolonged platelet survival, suggesting decreased platelet activation in vivo. Further studies with either genetic deletion or pharmacological inhibition of Cd39 in macrophages revealed increased cholesterol efflux mediated via ABCA1 to ApoA1. This phenomenon was associated with elevated plasma HDL levels in DKO mice. Our findings indicate that complete deletion of Cd39 paradoxically attenuates development of atherosclerosis in hyperlipidemic mice. We propose that this phenotype occurs, at least in part, from diminished platelet activation, increased plasma HDL levels, and enhanced cholesterol efflux and indicates the complexity of purinergic signaling in atherosclerosis.
Collapse
Affiliation(s)
- Marco De Giorgi
- Transplant Institute and Hepatology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA
| | - Keiichi Enjyoji
- Transplant Institute and Hepatology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA
| | - Gordon Jiang
- Transplant Institute and Hepatology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA
| | - Eva Csizmadia
- Transplant Institute and Hepatology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA
| | - Shuji Mitsuhashi
- Transplant Institute and Hepatology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA
| | - Richard J Gumina
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | | | - Simon C Robson
- Transplant Institute and Hepatology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA.
| |
Collapse
|
14
|
Nègre-Salvayre A, Augé N, Camaré C, Bacchetti T, Ferretti G, Salvayre R. Dual signaling evoked by oxidized LDLs in vascular cells. Free Radic Biol Med 2017; 106:118-133. [PMID: 28189852 DOI: 10.1016/j.freeradbiomed.2017.02.006] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Revised: 01/30/2017] [Accepted: 02/02/2017] [Indexed: 12/12/2022]
Abstract
The oxidative theory of atherosclerosis relies on the modification of low density lipoproteins (LDLs) in the vascular wall by reactive oxygen species. Modified LDLs, such as oxidized LDLs, are thought to participate in the formation of early atherosclerotic lesions (accumulation of foam cells and fatty streaks), whereas their role in advanced lesions and atherothrombotic events is more debated, because antioxidant supplementation failed to prevent coronary disease events and mortality in intervention randomized trials. As oxidized LDLs and oxidized lipids are present in atherosclerotic lesions and are able to trigger cell signaling on cultured vascular cells and macrophages, it has been proposed that they could play a role in atherogenesis and atherosclerotic vascular remodeling. Oxidized LDLs exhibit dual biological effects, which are dependent on extent of lipid peroxidation, nature of oxidized lipids (oxidized phospholipids, oxysterols, malondialdehyde, α,β-unsaturated hydroxyalkenals), concentration of oxidized LDLs and uptake by scavenger receptors (e.g. CD36, LOX-1, SRA) that signal through different transduction pathways. Moderate concentrations of mildly oxidized LDLs are proinflammatory and trigger cell migration and proliferation, whereas higher concentrations induce cell growth arrest and apoptosis. The balance between survival and apoptotic responses evoked by oxidized LDLs depends on cellular systems that regulate the cell fate, such as ceramide/sphingosine-1-phosphate rheostat, endoplasmic reticulum stress, autophagy and expression of pro/antiapoptotic proteins. In vivo, the intimal concentration of oxidized LDLs depends on the influx (hypercholesterolemia, endothelial permeability), residence time and lipid composition of LDLs, oxidative stress intensity, induction of defense mechanisms (antioxidant systems, heat shock proteins). As a consequence, the local cellular responses to oxidized LDLs may stimulate inflammatory or anti-inflammatory pathways, angiogenic or antiangiogenic responses, survival or apoptosis, thereby contributing to plaque growth, instability, complication (intraplaque hemorrhage, proteolysis, calcification, apoptosis) and rupture. Finally, these dual properties suggest that oxLDLs could be implicated at each step of atherosclerosis development, from early fatty streaks to advanced lesions, depending on the nature and concentration of their oxidized lipid content.
Collapse
Affiliation(s)
| | | | - Caroline Camaré
- Inserm UMR-1048, France; University of Toulouse, Faculty of Medicine, Biochemistry Dept, Toulouse, France; CHU Toulouse, Rangueil, Toulouse, France
| | | | | | - Robert Salvayre
- Inserm UMR-1048, France; University of Toulouse, Faculty of Medicine, Biochemistry Dept, Toulouse, France; CHU Toulouse, Rangueil, Toulouse, France.
| |
Collapse
|
15
|
Zhao M, Pan W, Shi RZ, Bai YP, You BY, Zhang K, Fu QM, Schuchman EH, He XX, Zhang GG. Acid Sphingomyelinase Mediates Oxidized-LDL Induced Apoptosis in Macrophage via Endoplasmic Reticulum Stress. J Atheroscler Thromb 2016; 23:1111-25. [PMID: 26923251 PMCID: PMC5090817 DOI: 10.5551/jat.32383] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Aim: Macrophage apoptosis is a vital event in advanced atherosclerosis, and oxidized low-density lipoprotein (ox-LDL) is a major contributor to this process. Acid sphingomyelinase (ASM) and ceramide are also involved in the induction of apoptosis, particularly in macrophages. Our current study focuses on ASM and investigates its role in ox-LDL-induced macrophage apoptosis. Methods: Human THP-1 and mouse peritoneal macrophages were cultured in vitro and treated with ox-LDL. ASM activity and ceramide levels were quantified using ultra performance liquid chromatography. Protein and mRNA levels were analyzed using Western blot analysis and quantitative realtime PCR, respectively. Cell apoptosis was determined using Hoechst staining and flow cytometry. Results: Ox-LDL-induced macrophage apoptosis was triggered by profound endoplasmic reticulum (ER) stress, leading to an upregulation of ASM activity and ceramide levels at an early stage. ASM was inhibited by siRNA or desipramine (DES), and/or ceramide was degraded by recombinant acid ceramidase (AC). These events attenuated the effect of ox-LDL on ER stress. In contrast, recombinant ASM upregulated ceramide and ER stress. ASM siRNA, DES, recombinant AC, and ER stress inhibitor 4-phenylbutyric acid were blocked by elevated levels of C/EBP homologous protein (CHOP); ox-LDL induced elevated levels of CHOP. These events attenuated macrophage apoptosis. Conclusion: These results indicate that ASM/ceramide signaling pathway is involved in ox-LDL-induced macrophage apoptosis via ER stress pathway.
Collapse
Affiliation(s)
- Min Zhao
- Departments of Nuclear Medicine, Xiangya Hospital, Central South University
| | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Ceramide 1-phosphate regulates cell migration and invasion of human pancreatic cancer cells. Biochem Pharmacol 2015; 102:107-119. [PMID: 26707801 DOI: 10.1016/j.bcp.2015.12.009] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 12/14/2015] [Indexed: 02/06/2023]
Abstract
Pancreatic cancer is an aggressive and devastating disease characterized by invasiveness, rapid progression and profound resistance to treatment. Despite years of intense investigation, the prognosis of this type of cancer is poor and there is no efficacious treatment to overcome the disease. Using human PANC-1 and MIA PaCa-2 cells, we demonstrate that the bioactive sphingolipid ceramide 1-phosphate (C1P) increases pancreatic cancer cell migration and invasion. Treatment of these cells with selective inhibitors of phosphatidylinositol 3-kinase (PI3K), Akt1, or mammalian target of rapamycin 1 (mTOR1), or with specific siRNAs to silence the genes encoding these kinases, resulted in potent inhibition of C1P-induced cell migration and invasion. Likewise, the extracellularly regulated kinases 1 and 2 (ERK1-2), and the small GTPase RhoA, which regulates cytoskeleton reorganization, were also found to be implicated in C1P-stimulated ROCK1-dependent cancer cell migration and invasion. In addition, pre-treatment of the cancer cells with pertussis toxin abrogated C1P-induced cell migration, suggesting the intervention of a Gi protein-coupled receptor in this process. Pancreatic cancer cells engineered to overexpress ceramide kinase (CerK), the enzyme responsible for C1P biosynthesis in mammalian cells, showed enhanced spontaneous cell migration that was potently blocked by treatment with the selective CerK inhibitor NVP-231, or by treatment with specific CerK siRNA. Moreover, overexpression of CerK with concomitant elevations in C1P enhanced migration of pancreatic cancer cells. Collectively, these data demonstrate that C1P is a key regulator of pancreatic cancer cell motility, and suggest that targeting CerK expression/activity and C1P may be relevant factors for controlling pancreatic cancer cell dissemination.
Collapse
|
17
|
Wang SW, Hojabrpour P, Zhang P, Kolesnick RN, Steinbrecher UP, Gómez-Muñoz A, Duronio V. Regulation of ceramide generation during macrophage apoptosis by ASMase and de novo synthesis. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:1482-9. [PMID: 26253821 DOI: 10.1016/j.bbalip.2015.08.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 07/17/2015] [Accepted: 08/03/2015] [Indexed: 12/29/2022]
Abstract
The survival of macrophages depends on the presence of specific cytokines that activate survival signaling events, as well as suppressing formation of apoptosis-inducing pathways. We have previously shown that macrophages deprived of macrophage colony stimulating factor (M-CSF) produce ceramide that contributes to apoptosis of these cells, a pathway that is suppressed by exposure to oxidized LDL. In this study we have examined macrophages derived from mice lacking acid sphingomyelinase (ASMase) to ask whether these events are altered due to the impaired ability of these cells to break down sphingomyelin and produce ceramide. We found that these cells do survive better than cells from wild type mice, but they still undergo cell death and some ceramide is formed. We show that the ceramide is being produced by a de novo synthetic pathway. Therefore, ceramide production in M-CSF-deprived macrophages arises from a combination of ASMase activity and de novo synthesis.
Collapse
Affiliation(s)
- Shih Wei Wang
- Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Payman Hojabrpour
- Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Peng Zhang
- Department of Medicine, University of British Columbia, Vancouver, Canada
| | | | - Urs P Steinbrecher
- Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Antonio Gómez-Muñoz
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country, P.O. Box 644, 48080 Bilbao, Spain
| | - Vincent Duronio
- Department of Medicine, University of British Columbia, Vancouver, Canada.
| |
Collapse
|
18
|
Phosphatidic acid inhibits ceramide 1-phosphate-stimulated macrophage migration. Biochem Pharmacol 2014; 92:642-50. [DOI: 10.1016/j.bcp.2014.10.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 10/03/2014] [Accepted: 10/06/2014] [Indexed: 02/06/2023]
|
19
|
Hydroxyoctadecadienoic Acids Regulate Apoptosis in Human THP-1 Cells in a PPARγ-Dependent Manner. Lipids 2014; 49:1181-92. [DOI: 10.1007/s11745-014-3954-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 09/11/2014] [Indexed: 12/13/2022]
|
20
|
Lee SJ, Thien Quach CH, Jung KH, Paik JY, Lee JH, Park JW, Lee KH. Oxidized low-density lipoprotein stimulates macrophage 18F-FDG uptake via hypoxia-inducible factor-1α activation through Nox2-dependent reactive oxygen species generation. J Nucl Med 2014; 55:1699-705. [PMID: 25214643 DOI: 10.2967/jnumed.114.139428] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
UNLABELLED For (18)F-FDG PET to be widely used to monitor atherosclerosis progression and therapeutic response, it is crucial to better understand how macrophage glucose metabolism is influenced by the atherosclerotic microenvironment and to elucidate the molecular mechanisms of this response. Oxidized low-density lipoprotein (oxLDL) is a key player in atherosclerotic inflammation that promotes macrophage recruitment, activation, and foam cell formation. We thus explored the effect of oxLDL on macrophage (18)F-FDG uptake and investigated the underlying molecular mechanism including the roles of hypoxia-inducible factor-1α (HIF-1α) and reactive oxygen species (ROS). METHODS RAW264.7 macrophages were stimulated with native LDL, oxLDL, or lipopolysaccharide. Cells were assessed for (18)F-FDG uptake, lactate production, membrane glucose transporter 1 (GLUT1) expression, and hexokinase activity. ROS generation, Nox expression, and HIF-1α activity were also measured. RESULTS oxLDL (20 μg/mL) induced a 17.5 ± 1.7-fold increase in macrophage (18)F-FDG uptake by 24 h, which was accompanied by increased lactate production, membrane GLUT1 expression, and hexokinase activity. oxLDL-stimulated (18)F-FDG uptake was completely blocked by inhibitors of Src or phosphoinositide 3-kinase. ROS generation was increased to 262.4% ± 17.9% of controls by oxLDL, and N-acetyl-l-cysteine completely abrogated both oxLDL-induced ROS production and (18)F-FDG uptake. oxLDL increased Nox2 expression, and nicotinamide adenine dinucleotide phosphate oxidase inhibition totally blocked increased ROS generation and (18)F-FDG uptake by oxLDL. Finally, there was a clear ROS-dependent increase of HIF-1α accumulation by oxLDL, and silencing of HIF-1α completely abolished the metabolic effect of oxLDL. CONCLUSION oxLDL is a strong stimulator of macrophage (18)F-FDG uptake and glycolysis through upregulation of GLUT1 and hexokinase. This metabolic response is mediated by Nox2-dependent ROS generation that promotes HIF-1α activation.
Collapse
Affiliation(s)
- Su Jin Lee
- Department of Nuclear Medicine, Ajou University School of Medicine, Suwon, Korea; and
| | - Cung Hoa Thien Quach
- Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Kyung-Ho Jung
- Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jin-Young Paik
- Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jin Hee Lee
- Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jin Won Park
- Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Kyung-Han Lee
- Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| |
Collapse
|
21
|
Chen T, Wang X, Guo L, Wu M, Duan Z, Lv J, Tai W, Renganathan H, Didier R, Li J, Sun D, Chen X, He X, Fan J, Young W, Ren Y. Embryonic Stem Cells Promoting Macrophage Survival and Function are Crucial for Teratoma Development. Front Immunol 2014; 5:275. [PMID: 25071759 PMCID: PMC4082241 DOI: 10.3389/fimmu.2014.00275] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 05/27/2014] [Indexed: 11/29/2022] Open
Abstract
Stem cell therapies have had tremendous potential application for many diseases in recent years. However, the tumorigenic properties of stem cells restrict their potential clinical application; therefore, strategies for reducing the tumorigenic potential of stem cells must be established prior to transplantation. We have demonstrated that syngeneic transplantation of embryonic stem cells (ESCs) provokes an inflammatory response that involves the rapid recruitment of bone marrow-derived macrophages (BMDMs). ESCs are able to prevent mature macrophages from macrophage colony-stimulating factor (M-CSF) withdrawal-induced apoptosis, and thus prolong macrophage lifespan significantly by blocking various apoptotic pathways in an M-CSF-independent manner. ESCs express and secrete IL-34, which may be responsible for ESC-promoted macrophage survival. This anti-apoptotic effect of ESCs involves activation of extracellular signal-regulated kinase (ERK)1/2 and PI3K/Akt pathways and thus, inhibition of ERK1/2 and PI3K/AKT activation decreases ESC-induced macrophage survival. Functionally, ESC-treated macrophages also showed a higher level of phagocytic activity. ESCs further serve to polarize BMDMs into M2-like macrophages that exhibit most tumor-associated macrophage phenotypic and functional features. ESC-educated macrophages produce high levels of arginase-1, Tie-2, and TNF-α, which participate in angiogenesis and contribute to teratoma progression. Our study suggests that induction of M2-like macrophage activation is an important mechanism for teratoma development. Strategies targeting macrophages to inhibit teratoma development would increase the safety of ESC-based therapies, inasmuch as the depletion of macrophages completely inhibits ESC-induced angiogenesis and teratoma development.
Collapse
Affiliation(s)
- Tianxiang Chen
- W. M. Keck Center for Collaborative Neuroscience, Rutgers, The State University of New Jersey , New Jersey, NJ , USA ; Department of Thoracic Surgery, First Affiliated Hospital, School of Medicine, Zhejiang University , Hangzhou , China
| | - Xi Wang
- W. M. Keck Center for Collaborative Neuroscience, Rutgers, The State University of New Jersey , New Jersey, NJ , USA ; Institute of Neurosciences, The Fourth Military Medical University , Xian , China
| | - Lei Guo
- Department of Biomedical Sciences, Florida State University College of Medicine , Tallahassee, FL , USA ; Department of Orthopedic Surgery, The Second Hospital of Xian Jiaotong University , Xian , China
| | - Mingmei Wu
- W. M. Keck Center for Collaborative Neuroscience, Rutgers, The State University of New Jersey , New Jersey, NJ , USA
| | - Zhaoxia Duan
- W. M. Keck Center for Collaborative Neuroscience, Rutgers, The State University of New Jersey , New Jersey, NJ , USA
| | - Jing Lv
- Department of Biomedical Sciences, Florida State University College of Medicine , Tallahassee, FL , USA
| | - Wenjiao Tai
- Department of Biomedical Sciences, Florida State University College of Medicine , Tallahassee, FL , USA
| | - Hemamalini Renganathan
- W. M. Keck Center for Collaborative Neuroscience, Rutgers, The State University of New Jersey , New Jersey, NJ , USA
| | - Ruth Didier
- Department of Biomedical Sciences, Florida State University College of Medicine , Tallahassee, FL , USA
| | - Jinhua Li
- Department of Anatomy and Developmental Biology, Monash University , Clayton, VIC , Australia
| | - Dongming Sun
- W. M. Keck Center for Collaborative Neuroscience, Rutgers, The State University of New Jersey , New Jersey, NJ , USA
| | - Xiaoming Chen
- Institute of Translational Medicine, First Affiliated Hospital, Wenzhou Medical University , Wenzhou , China
| | - Xijing He
- Department of Orthopedic Surgery, The Second Hospital of Xian Jiaotong University , Xian , China
| | - Jianqing Fan
- Statistics Laboratory, Princeton University , Princeton, NJ , USA
| | - Wise Young
- W. M. Keck Center for Collaborative Neuroscience, Rutgers, The State University of New Jersey , New Jersey, NJ , USA
| | - Yi Ren
- Department of Biomedical Sciences, Florida State University College of Medicine , Tallahassee, FL , USA
| |
Collapse
|
22
|
Yu X, Wang Y, Zhao W, Zhou H, Yang W, Guan X. Toll-like receptor 7 promotes the apoptosis of THP-1-derived macrophages through the CHOP-dependent pathway. Int J Mol Med 2014; 34:886-93. [PMID: 24994112 DOI: 10.3892/ijmm.2014.1833] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 06/25/2014] [Indexed: 11/06/2022] Open
Abstract
Macrophage apoptosis is a prominent characteristic of advanced atherosclerotic plaques and leads to plaque destabilization. Certain studies have confirmed that influenza virus A (IVA) infection is related to acute myocardial infarction (AMI). However, it remains unknown as to whether this phenomenon is associated with Toll-like receptor (TLR)7, since single-stranded RNA (ssRNA) of IVA is a natural ligand of TLR7. Thus, in the present study, THP-1‑derived macrophages were infected with IVA or treated with imiquimod (IMQ) in the presence or absence of pre-treatment with oxidized low-density lipoprotein (oxLDL). The macrophages were pre-treated with oxLDL (5 µg/ml) for 24 h to mimic high lipid conditions. Cell viability and apoptosis were detected by 3-(4,5-dimethylthiazol-2-y-1)‑2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and flow cytometry, respectively. Our results revealed that TLR7 played an important role in macrophage apoptosis and cytokine secretion. Both IVA infection and IMQ treatment increased TLR7 expression, as well as the secretion of pro-inflammatory cytokines [interleukin (IL)-6, monocyte chemotactic protein (MCP)-1] and apoptosis. However, this increase in cytokine secretion occurred independently of cell apoptosis. oxLDL had potential synergistic pro-apoptotic effects combined with TLR7 activation. To determine whether endoplasmic reticulum (ER) stress plays a role in cell apoptosis, the mRNA and protein expression of known markers of ER stress [glucose-regulated protein (GRP)78 and C/EBP homologous protein (CHOP)] was detected by reverse transcription PCR (RT-PCR), quantitative reverse transcription PCR (qRT-PCR) and western blot analysis. Our results revealed that apoptosis aggravated ER stress, as shown by the overexpression of the pro-apoptotic sensor, CHOP. In conclusion, our study demonstrates the converging role of oxLDL pre-treatment, IVA infection and IMQ in ER stress-induced cell apoptosis.
Collapse
Affiliation(s)
- Xiaochen Yu
- Department of Laboratory Diagnostics, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Yang Wang
- Department of Laboratory Diagnostics, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Wenhui Zhao
- Department of Laboratory Diagnostics, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Haizhou Zhou
- Department of Laboratory Diagnostics, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Wei Yang
- Department of Laboratory Diagnostics, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Xiuru Guan
- Department of Laboratory Diagnostics, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| |
Collapse
|
23
|
Amézaga N, Sanjurjo L, Julve J, Aran G, Pérez-Cabezas B, Bastos-Amador P, Armengol C, Vilella R, Escolà-Gil JC, Blanco-Vaca F, Borràs FE, Valledor AF, Sarrias MR. Human scavenger protein AIM increases foam cell formation and CD36-mediated oxLDL uptake. J Leukoc Biol 2013; 95:509-20. [PMID: 24295828 DOI: 10.1189/jlb.1212660] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
AIM is expressed by macrophages in response to agonists of the nuclear receptors LXR/RXR. In mice, it acts as an atherogenic factor by protecting macrophages from the apoptotic effects of oxidized lipids. In humans, it is detected in atherosclerotic lesions, but no role related to atherosclerosis has been reported. This study aimed to investigate whether the role of hAIM extends beyond inhibiting oxidized lipid-induced apoptosis. To accomplish this goal, functional analysis with human monocytic THP1 cells and macrophages differentiated from peripheral blood monocytes were performed. It was found that hAIM reduced oxLDL-induced macrophage apoptosis and increased macrophage adhesion to endothelial ICAM-1 by enhancing LFA-1 expression. Furthermore, hAIM increased foam cell formation, as shown by Oil Red O and Nile Red staining, as well as quantification of cholesterol content. This was not a result of decreased reverse cholesterol transport, as hAIM did not affect the efflux significantly from [(3)H] Cholesterol-laden macrophages driven by plasma, apoA-I, or HDL2 acceptors. Rather, flow cytometry studies indicated that hAIM increased macrophage endocytosis of fluorescent oxLDL, which correlated with an increase in the expression of the oxLDLR CD36. Moreover, hAIM bound to oxLDL in ELISA and enhanced the capacity of HEK-293 cells expressing CD36 to endocytose oxLDL, as studied using immunofluorescence microscopy, suggesting that hAIM serves to facilitate CD36-mediated uptake of oxLDL. Our data represent the first evidence that hAIM is involved in macrophage survival, adhesion, and foam cell formation and suggest a significant contribution to atherosclerosis-related mechanisms in the macrophage.
Collapse
Affiliation(s)
- Núria Amézaga
- 1.Ctra Can Ruti, camí de les escoles s/n, Edifici de Recerca, Planta 1, 08916 Badalona, Spain. ; Twitter: http://www.twitter.com/mrsarrias
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Thompson MR, Xu D, Williams BR. Activating Transcription Factor 3 Contributes to Toll-Like Receptor-Mediated Macrophage Survival via Repression ofBaxandBak. J Interferon Cytokine Res 2013; 33:682-93. [DOI: 10.1089/jir.2013.0007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Matthew R. Thompson
- Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia
| | - Dakang Xu
- Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia
| | - Bryan R.G. Williams
- Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia
| |
Collapse
|
25
|
Hwabejire JO, Lu J, Liu B, Li Y, Halaweish I, Alam HB. Valproic acid for the treatment of hemorrhagic shock: a dose-optimization study. J Surg Res 2013; 186:363-70. [PMID: 24135375 DOI: 10.1016/j.jss.2013.09.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Revised: 09/11/2013] [Accepted: 09/12/2013] [Indexed: 11/19/2022]
Abstract
BACKGROUND Valproic acid (VPA) has been shown to improve survival in animal models of hemorrhagic shock at a dose of 300 mg/kg. Our aim was to identify the ideal dose through dose-escalation, split-dosing, and dose de-escalation regimens. MATERIALS AND METHODS Rats were subjected to sublethal 40% hemorrhage and treated with vehicle or VPA (dose of 300, 400, or 450 mg/kg) after 30 min of shock. Acetylated histones and activated proteins from the PI3K-Akt-GSK-3β survival pathway at different time points were quantified by Western blot analysis. In a similar model, a VPA dose of 200 mg/kg followed 2 h later by another dose of 100 mg/kg was administered. Finally, animals were subjected to a lethal 50% hemorrhage and VPA was administered in a dose de-escalation manner (starting at dose of 300 mg/kg) until a significant drop in percent survival was observed. RESULTS Larger doses of VPA resulted in greater acetylation of histone 3 and increased activation of PI3K pathway proteins. Dose-dependent differences were significant in histone acetylation but not in the activation of the survival pathway proteins. Split-dose administration of VPA resulted in similar results to a single full dose. Survival was as follows: 87.5% with 300 and 250 mg/kg of VPA, 50% with 200 mg/kg of VPA, and 14% with vehicle-treated animals. CONCLUSIONS Although higher doses of VPA result in greater histone acetylation and activation of prosurvival protein signaling, doses as low as 250 mg/kg of VPA confer the same survival advantage in lethal hemorrhagic shock. Also, VPA can be given in a split-dose fashion without a reduction in its cytoprotective effectiveness.
Collapse
Affiliation(s)
- John O Hwabejire
- Division of Trauma, Emergency Surgery and Surgical Critical Care, Department of Surgery, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts
| | | | | | | | | | | |
Collapse
|
26
|
Lopes-Virella MF, Virella G. The role of immunity and inflammation in the development of diabetic complications. Diabetol Int 2013. [DOI: 10.1007/s13340-013-0105-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
|
27
|
Ouro A, Arana L, Gangoiti P, Rivera IG, Ordoñez M, Trueba M, Lankalapalli RS, Bittman R, Gomez-Muñoz A. Ceramide 1-phosphate stimulates glucose uptake in macrophages. Cell Signal 2013; 25:786-95. [PMID: 23333242 DOI: 10.1016/j.cellsig.2013.01.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 12/28/2012] [Accepted: 01/07/2013] [Indexed: 12/24/2022]
Abstract
It is well established that ceramide 1-phosphate (C1P) is mitogenic and antiapoptotic, and that it is implicated in the regulation of macrophage migration. These activities require high energy levels to be available in cells. Macrophages obtain most of their energy from glucose. In this work, we demonstrate that C1P enhances glucose uptake in RAW264.7 macrophages. The major glucose transporter involved in this action was found to be GLUT 3, as determined by measuring its translocation from the cytosol to the plasma membrane. C1P-stimulated glucose uptake was blocked by selective inhibitors of phosphatidylinositol 3-kinase (PI3K) or Akt, also known as protein kinase B (PKB), and by specific siRNAs to silence the genes encoding for these kinases. C1P-stimulated glucose uptake was also inhibited by pertussis toxin (PTX) and by the siRNA that inhibited GLUT 3 expression. C1P increased the affinity of the glucose transporter for its substrate, and enhanced glucose metabolism to produce ATP. The latter action was also inhibited by PI3K- and Akt-selective inhibitors, PTX, or by specific siRNAs to inhibit GLUT 3 expression.
Collapse
Affiliation(s)
- Alberto Ouro
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), 48080 Bilbao, Spain
| | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Macrophages actively accumulate malonyldialdehyde-modified but not enzymatically oxidized low density lipoprotein. Mol Cell Biochem 2012; 365:93-8. [DOI: 10.1007/s11010-012-1247-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Accepted: 01/14/2012] [Indexed: 11/26/2022]
|
29
|
Arana L, Gangoiti P, Ouro A, Rivera IG, Ordoñez M, Trueba M, Lankalapalli RS, Bittman R, Gomez-Muñoz A. Generation of reactive oxygen species (ROS) is a key factor for stimulation of macrophage proliferation by ceramide 1-phosphate. Exp Cell Res 2012; 318:350-60. [DOI: 10.1016/j.yexcr.2011.11.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Revised: 11/16/2011] [Accepted: 11/24/2011] [Indexed: 11/26/2022]
|
30
|
Greig FH, Kennedy S, Spickett CM. Physiological effects of oxidized phospholipids and their cellular signaling mechanisms in inflammation. Free Radic Biol Med 2012; 52:266-80. [PMID: 22080084 DOI: 10.1016/j.freeradbiomed.2011.10.481] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Revised: 10/25/2011] [Accepted: 10/25/2011] [Indexed: 12/31/2022]
Abstract
Oxidized phospholipids, such as the products of the oxidation of 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine by nonenzymatic radical attack, are known to be formed in a number of inflammatory diseases. Interest in the bioactivity and signaling functions of these compounds has increased enormously, with many studies using cultured immortalized and primary cells, tissues, and animals to understand their roles in disease pathology. Initially, oxidized phospholipids were viewed largely as culprits, in line with observations that they have proinflammatory effects, enhancing inflammatory cytokine production, cell adhesion and migration, proliferation, apoptosis, and necrosis, especially in vascular endothelial cells, macrophages, and smooth muscle cells. However, evidence has emerged that these compounds also have protective effects in some situations and cell types; a notable example is their ability to interfere with signaling by certain Toll-like receptors (TLRs) induced by microbial products that normally leads to inflammation. They also have protective effects via the stimulation of small GTPases and induce up-regulation of antioxidant enzymes and cytoskeletal rearrangements that improve endothelial barrier function. Oxidized phospholipids interact with several cellular receptors, including scavenger receptors, platelet-activating factor receptors, peroxisome proliferator-activated receptors, and TLRs. The various and sometimes contradictory effects that have been observed for oxidized phospholipids depend on their concentration, their specific structure, and the cell type investigated. Nevertheless, the underlying molecular mechanisms by which oxidized phospholipids exert their effects in various pathologies are similar. Although our understanding of the actions and mechanisms of these mediators has advanced substantially, many questions do remain about their precise interactions with components of cell signaling pathways.
Collapse
Affiliation(s)
- Fiona H Greig
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | | | | |
Collapse
|
31
|
Virella G, Lopes-Virella MF. The Pathogenic Role of the Adaptive Immune Response to Modified LDL in Diabetes. Front Endocrinol (Lausanne) 2012; 3:76. [PMID: 22715334 PMCID: PMC3375400 DOI: 10.3389/fendo.2012.00076] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 05/28/2012] [Indexed: 01/12/2023] Open
Abstract
The main causes of morbidity and mortality in diabetes are macro and microvascular complications, including atherosclerosis, nephropathy, and retinopathy. As the definition of atherosclerosis as a chronic inflammatory disease became widely accepted, it became important to define the triggers of vascular inflammation. Oxidative and other modifications of lipids and lipoproteins emerged as major pathogenic factors in atherosclerosis. Modified forms of LDL (mLDL) are pro-inflammatory by themselves, but, in addition, mLDLs including oxidized, malondialdehyde (MDA)-modified, and advanced glycation end (AGE)-product-modified LDL induce autoimmune responses in humans. The autoimmune response involves T cells in the arterial wall and synthesis of IgG antibodies. The IgG auto-antibodies that react with mLDLs generate immune complexes (IC) both intra and extravascularly, and those IC activate the complement system as well as phagocytic cells via the ligation of Fcγ receptors. In vitro studies proved that the pro-inflammatory activity of IC containing mLDL (mLDL-IC) is several-fold higher than that of the modified LDL molecules. Clinical studies support the pathogenic role of mLDL-IC in the development of macrovascular disease patients with diabetes. In type 1 diabetes, high levels of oxidized and AGE-LDL in IC were associated with internal carotid intima-media thickening and coronary calcification. In type 2 diabetes, high levels of MDA-LDL in IC predicted the occurrence of myocardial infarction. There is also evidence that mLDL-IC are involved in the pathogenesis of diabetic nephropathy and retinopathy. The pathogenic role of mLDL-IC is not unique to diabetic patients, because those IC are also detected in non-diabetic individuals. But mLDL-IC are likely to reach higher concentrations and have a more prominent pathogenic role in diabetes due to increased antigenic load secondary to high oxidative stress and to enhanced autoimmune responses in type 1 diabetes.
Collapse
Affiliation(s)
- Gabriel Virella
- Department of Microbiology and Immunology, Medical University of South CarolinaCharleston, SC, USA
- *Correspondence: Gabriel Virella, Department of Microbiology and Immunology, Medical University of South Carolina, 173 Ashley Avenue, MSC 504, Charleston, SC 29425-5040, USA. e-mail:
| | - Maria F. Lopes-Virella
- Department of Microbiology and Immunology, Medical University of South CarolinaCharleston, SC, USA
- Ralph E. Johnson VA Medical CenterCharleston, SC, USA
| |
Collapse
|
32
|
Riazy M, Lougheed M, Adomat HH, Guns EST, Eigendorf GK, Duronio V, Steinbrecher UP. Fluorescent adducts formed by reaction of oxidized unsaturated fatty acids with amines increase macrophage viability. Free Radic Biol Med 2011; 51:1926-36. [PMID: 21930200 DOI: 10.1016/j.freeradbiomed.2011.08.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 08/22/2011] [Accepted: 08/24/2011] [Indexed: 10/17/2022]
Abstract
Macrophages are prominent components of human atherosclerotic lesions and they are believed to accelerate the progression and/or complications of both early and advanced atherosclerotic lesions. We and others have shown that oxidized low-density lipoprotein (oxLDL) induces growth and inhibits apoptosis in murine bone marrow-derived macrophages. In this study, we sought to characterize the oxidative modification of LDL that is responsible for this prosurvival effect. We found that both the modified lipid and the modified protein components of oxLDL can increase the viability of macrophages. The key modification appeared to involve derivatization of amino groups in apoB or in phosphatidylethanolamine by lipid peroxidation products. These reactive oxidation products were primarily unfragmented hydroperoxide- or endoperoxide-containing oxidation products of linoleic acid or arachidonic acid. LC-MS/MS studies showed that some of the arachidonic acid-derived lysine adducts were isolevuglandins that contain lactam and hydroxylactam rings. MS/MS analysis of linoleic acid autoxidation adducts was consistent with 5- or 6-membered nitrogen-containing heterocycles derived from unfragmented oxidation products. The amine modification by oxidation products generated a fluorescence pattern with an excitation maximum at 350nm and emission maximum at 430nm. This is very similar to the fluorescence spectrum of copper-oxidized LDL.
Collapse
Affiliation(s)
- Maziar Riazy
- Department of Medicine, University of British Columbia, and Vancouver Coastal Health Research Institute, Vancouver, BC, Canada.
| | | | | | | | | | | | | |
Collapse
|
33
|
Riazy M, Chen JH, Yamamato Y, Yamamato H, Duronio V, Steinbrecher UP. OxLDL-mediated survival of macrophages does not require LDL internalization or signalling by major pattern recognition receptors. Biochem Cell Biol 2011; 89:387-95. [DOI: 10.1139/o11-035] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Macrophages play a key role in the pathogenesis of atherosclerosis, in part by destabilizing plaques. We and others have shown that low concentrations of oxidized LDL (oxLDL) inhibit macrophage apoptosis. As oxLDL is present in lesions, this may be a mechanism by which macrophage populations in the intima are expanded. We have previously shown that oxLDL activates prosurvival signalling pathways such as the phosphoinositide 3-kinase (PI3K) pathway in bone marrow derived macrophages (BMDMs). However, little is known about more upstream signalling events especially at the receptor level. The endocytic pattern recognition receptors (PRRs), scavenger receptor A (SR-A) and CD36, are the main receptors on macrophages for uptake of oxLDL and are therefore important in foam cell formation. The signalling PRRs such as toll-like receptor (TLR) 2 and 4 also bind some types of oxLDL. This study was done to determine if any of the known PRRs are required for the anti-apoptotic effects of oxLDL in BMDMs. To do this, we tested the effect of oxLDL on viability of BMDMs lacking both SR-A and CD36 or lacking TLR2, TLR4, CD14, FcγRIIb, or RAGE. Our results indicate that none of these receptors are essential for activating the oxLDL prosurvival pathway. Furthermore, we show that the anti-apoptotic effect is not dependent on the uptake of oxLDL.
Collapse
Affiliation(s)
- Maziar Riazy
- Department of Medicine, University of British Columbia, Vancouver, BC V5Z 1M9, Canada
- Rm 444A- Jack Bell Research Centre, 2660 Oak Street, Vancouver, BC V6H 3Z6, Canada
| | - Johnny H. Chen
- Department of Medicine, University of British Columbia, Vancouver, BC V5Z 1M9, Canada
| | - Yasuhiko Yamamato
- Department of Biochemistry and Molecular Biology, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
| | - Hiroshi Yamamato
- Department of Biochemistry and Molecular Biology, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
| | - Vincent Duronio
- Department of Medicine, University of British Columbia, Vancouver, BC V5Z 1M9, Canada
| | - Urs P. Steinbrecher
- Department of Medicine, University of British Columbia, Vancouver, BC V5Z 1M9, Canada
- Division of Gastroenterology, 5th floor, Diamond Health Care Center, 2775 Laurel St, Vancouver, BC V5Z 1M9, Canada
| |
Collapse
|
34
|
Yancey PG, Ding Y, Fan D, Blakemore JL, Zhang Y, Ding L, Zhang J, Linton MF, Fazio S. Low-density lipoprotein receptor-related protein 1 prevents early atherosclerosis by limiting lesional apoptosis and inflammatory Ly-6Chigh monocytosis: evidence that the effects are not apolipoprotein E dependent. Circulation 2011; 124:454-64. [PMID: 21730304 DOI: 10.1161/circulationaha.111.032268] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND We previously demonstrated that macrophage low-density lipoprotein receptor (LDLR)-related protein 1 (LRP1) deficiency increases atherosclerosis despite antiatherogenic changes including decreased uptake of remnants and increased secretion of apolipoprotein E (apoE). Thus, our objective was to determine whether the atheroprotective effects of LRP1 require interaction with apoE, one of its ligands with multiple beneficial effects. METHODS AND RESULTS We examined atherosclerosis development in mice with specific deletion of macrophage LRP1 (apoE(-/-) MΦLRP1(-/-)) and in LDLR(-/-) mice reconstituted with apoE(-/-) MΦLRP1(-/-) bone marrow. The combined absence of apoE and LRP1 promoted atherogenesis more than did macrophage apoE deletion alone in both apoE-producing LDLR(-/-) mice (+88%) and apoE(-/-) mice (+163%). The lesions of both mouse models with apoE(-/-) LRP1(-/-) macrophages had increased macrophage content. In vitro, apoE and LRP1 additively inhibit macrophage apoptosis. Furthermore, there was excessive accumulation of apoptotic cells in lesions of both LDLR(-/-) mice (+110%) and apoE(-/-) MΦLRP1(-/-) mice (+252%). The apoptotic cell accumulation was partially due to decreased efferocytosis as the ratio of free to cell-associated apoptotic nuclei was 3.5-fold higher in lesions of apoE(-/-) MΦLRP1(-/-) versus apoE(-/-) mice. Lesion necrosis was also increased (6 fold) in apoE(-/-) MΦLRP1(-/-) versus apoE(-/-) mice. Compared with apoE(-/-) mice, the spleens of apoE(-/-) MΦLRP1(-/-) mice contained 1.6- and 2.4-fold more total and Ly6-C(high) monocytes. Finally, there were 3.6- and 2.4-fold increases in Ly6-C(high) and CC-chemokine receptor 2-positive cells in lesions of apoE(-/-) MΦLRP1(-/-) versus apoE(-/-) mice, suggesting that accumulation of apoptotic cells enhances lesion development and macrophage content by promoting the recruitment of inflammatory monocytes. CONCLUSION Low-density lipoprotein receptor protein 1 exerts antiatherogenic effects via pathways independent of apoE involving macrophage apoptosis and monocyte recruitment.
Collapse
Affiliation(s)
- Patricia G Yancey
- Atherosclerosis Research Unit, Division of Cardiology, Department of Medicine, Vanderbilt University Medical Center, 2220 Pierce Avenue, Nashville, TN 37232, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Truman JP, Al Gadban MM, Smith KJ, Hammad SM. Acid sphingomyelinase in macrophage biology. Cell Mol Life Sci 2011; 68:3293-305. [PMID: 21533981 DOI: 10.1007/s00018-011-0686-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 03/28/2011] [Accepted: 04/05/2011] [Indexed: 12/21/2022]
Abstract
Macrophages play a central role in innate immune responses, in disposal of cholesterol, and in tissue homeostasis and remodeling. To perform these vital functions macrophages display high endosomal/lysosomal activities. Recent studies have highlighted that acid sphingomyelinase (ASMase), which generates ceramide from sphingomyelin, is involved in modulation of membrane structures and signal transduction in addition to its metabolic role in the lysosome. In this review, we bring together studies on ASMase, its different forms and locations that are necessary for the macrophage to accomplish its diverse functions. We also address the importance of ASMase to several disease processes that are mediated by activated macrophages.
Collapse
Affiliation(s)
- Jean-Philip Truman
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC 29425, USA
| | | | | | | |
Collapse
|
36
|
Jamil S, Wang SW, Bondy L, Mojtabavi S, Duronio V. Prevention of cytokine withdrawal-induced apoptosis by Mcl-1 requires interaction between Mcl-1 and Bim. Biochem Cell Biol 2011; 88:809-18. [PMID: 20921992 DOI: 10.1139/o10-004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Growth factor withdrawal from hemopoietic cells results in activation of the mitochondrial pathway of apoptosis. Members of the Bcl-2 family regulate this pathway, with anti-apoptotic members counteracting the effects of pro-apoptotic members. We investigated the effect on Mcl-1 function of mutation at a conserved threonine 163 residue (T163) in its proline, glutamate, serine, and threonine rich (PEST) region. Under normal growth conditions, Mcl-1 half-life increased with alteration of T163 to glutamic acid, but decreased with mutation to alanine. However, both T163 mutants exhibited greater pro-survival effects compared with the wild type, which can be explained by an increased stability of the T163A mutant in cytokine-starved conditions. Both the mutant forms exhibited prolonged binding to pro-apoptotic Bim in cytokine-deprived cells. The extent to which Mcl-1 mutants were able to exert their anti-apoptotic effects correlated with their ability to associate with Bim. We further observed that primary bone marrow derived macrophages survived following cytokine withdrawal as long as Bim and Mcl-1 remained associated. In our study, we were unable to detect a role for GSK-3-mediated regulation of Mcl-1 expression. Based on these results we propose that upon cytokine withdrawal, survival of hemopoietic cells depends on association between Mcl-1 and Bim. Furthermore, alteration of T163 of Mcl-1 may change the protein such that its association with Bim is affected, resulting in prolonged association and increased survival.
Collapse
Affiliation(s)
- Sarwat Jamil
- Department of Medicine, University of British Columbia and Vancouver Coastal Health Research Institute, Vancouver, BC V6H 3Z6, Canada
| | | | | | | | | |
Collapse
|
37
|
Torres F, Quintana J, Estévez F. 5,7,3'-Trihydroxy-3,4'-dimethoxyflavone inhibits the tubulin polymerization and activates the sphingomyelin pathway. Mol Carcinog 2010; 50:113-22. [PMID: 21229608 DOI: 10.1002/mc.20693] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Revised: 09/01/2010] [Accepted: 09/17/2010] [Indexed: 02/03/2023]
Abstract
Flavonoids are polyphenolic compounds which display a vast array of biological activities and are among the most promising anti-cancer agents. The derivative of quercetin, 5,7,3'-trihydroxy-3,4'-dimethoxyflavone (THDF), is a natural flavonoid that inhibits cell proliferation and induces apoptosis in human leukemia cells. Here we show that THDF induces cell-cycle arrest in the M phase and inhibits tubulin polymerization. This was associated with the accumulation of cyclin B1 and p21(Cip1) , changes in the phosphorylation status of cyclin B1, Cdk1, Cdc25C, and MPM-2, and activation of the acidic sphingomyelinase (ASMase). Moreover, desipramine attenuated THDF-mediated cell death, indicating a crucial role of ASMase in the mechanism of cell death. In vivo studies on the athymic nude mouse xenograft model also confirmed that THDF inhibits growth of human leukemia cells and suggest that this compound may have therapeutic value.
Collapse
Affiliation(s)
- Fernando Torres
- Department of Biochemistry and Molecular Biology, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | | | | |
Collapse
|
38
|
Gangoiti P, Camacho L, Arana L, Ouro A, Granado MH, Brizuela L, Casas J, Fabriás G, Abad JL, Delgado A, Gómez-Muñoz A. Control of metabolism and signaling of simple bioactive sphingolipids: Implications in disease. Prog Lipid Res 2010; 49:316-34. [PMID: 20193711 DOI: 10.1016/j.plipres.2010.02.004] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Revised: 02/18/2010] [Accepted: 02/22/2010] [Indexed: 01/05/2023]
Abstract
Simple bioactive sphingolipids include ceramide, sphingosine and their phosphorylated forms sphingosine 1-phosphate and ceramide 1-phosphate. These molecules are crucial regulators of cell functions. In particular, they play important roles in the regulation of angiogenesis, apoptosis, cell proliferation, differentiation, migration, and inflammation. Decoding the mechanisms by which these cellular functions are regulated requires detailed understanding of the signaling pathways that are implicated in these processes. Most importantly, the development of inhibitors of the enzymes involved in their metabolism may be crucial for establishing new therapeutic strategies for treatment of disease.
Collapse
Affiliation(s)
- Patricia Gangoiti
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Arana L, Gangoiti P, Ouro A, Trueba M, Gómez-Muñoz A. Ceramide and ceramide 1-phosphate in health and disease. Lipids Health Dis 2010; 9:15. [PMID: 20137073 PMCID: PMC2828451 DOI: 10.1186/1476-511x-9-15] [Citation(s) in RCA: 146] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2009] [Accepted: 02/05/2010] [Indexed: 01/06/2023] Open
Abstract
Sphingolipids are essential components of cell membranes, and many of them regulate vital cell functions. In particular, ceramide plays crucial roles in cell signaling processes. Two major actions of ceramides are the promotion of cell cycle arrest and the induction of apoptosis. Phosphorylation of ceramide produces ceramide 1-phosphate (C1P), which has opposite effects to ceramide. C1P is mitogenic and has prosurvival properties. In addition, C1P is an important mediator of inflammatory responses, an action that takes place through stimulation of cytosolic phospholipase A2, and the subsequent release of arachidonic acid and prostaglandin formation. All of the former actions are thought to be mediated by intracellularly generated C1P. However, the recent observation that C1P stimulates macrophage chemotaxis implicates specific plasma membrane receptors that are coupled to Gi proteins. Hence, it can be concluded that C1P has dual actions in cells, as it can act as an intracellular second messenger to promote cell survival, or as an extracellular receptor agonist to stimulate cell migration.
Collapse
Affiliation(s)
- Lide Arana
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | | | | | | | | |
Collapse
|
40
|
Abstract
There is renewed interest in high-density lipoproteins (HDLs) due to recent findings linking atherosclerosis to the formation of dysfunctional HDL. This article focuses on the universe of HDL lipids and their potential protective or proinflammatory roles in vascular disease and insulin resistance. HDL carries a wide array of lipids including sterols, triglycerides, fat-soluble vitamins, and a large number of phospholipids, including phosphatidylcholine, sphingomyelin, and ceramide with many biological functions. Ceramide has been implicated in the pathogenesis of insulin resistance and has many proinflammatory properties. In contrast, sphingosine-1-phosphate, which is transported mainly in HDL, has anti-inflammatory properties that may be atheroprotective and may account for some of the beneficial effects of HDL. However, the complexity of the HDL lipidome is only beginning to reveal itself. The emergence of new analytical technologies should rapidly increase our understanding of the function of HDL lipids and their role in disease states.
Collapse
Affiliation(s)
- Andrew N Hoofnagle
- Department of Laboratory Medicine, University of Washington School of Medicine, Mailstop 358055, 815 Mercer Street, Seattle, WA 98109, USA
| | | | | | | |
Collapse
|
41
|
Lankalapalli RS, Ouro A, Arana L, Gómez-Muñoz A, Bittman R. Caged ceramide 1-phosphate analogues: synthesis and properties. J Org Chem 2010; 74:8844-7. [PMID: 19908915 DOI: 10.1021/jo902076w] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Sphingolipid phosphate analogues bearing 7-(diethylamino)coumarin (DECM) and 4-bromo-5-hydroxy-2-nitrobenzhydryl (BHNB) groups in a photolabile ester bond were synthesized. The ability of the "caged" ceramide 1-phosphate analogues to release the bioactive parent molecule upon irradiation at 400-500 nm was demonstrated by stimulation of macrophage cell proliferation.
Collapse
Affiliation(s)
- Ravi S Lankalapalli
- Department of Chemistry and Biochemistry, Queens College of The City University of New York, Flushing, New York 11367-1597, USA
| | | | | | | | | |
Collapse
|
42
|
Gómez-Muñoz A, Gangoiti P, Granado MH, Arana L, Ouro A. Ceramide-1-Phosphate in Cell Survival and Inflammatory Signaling. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 688:118-30. [DOI: 10.1007/978-1-4419-6741-1_8] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
43
|
Chen JH, Riazy M, Wang SW, Dai JM, Duronio V, Steinbrecher UP. Sphingosine kinase regulates oxidized low density lipoprotein-mediated calcium oscillations and macrophage survival. J Lipid Res 2009; 51:991-8. [PMID: 19965613 DOI: 10.1194/jlr.m000398] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We recently reported that oxidized LDL (oxLDL) induces an oscillatory increase in intracellular calcium ([Ca(2+)](i)) levels in macrophages. Furthermore, we have shown that these [Ca(2+)](i) oscillations mediate oxLDL's ability to inhibit macrophage apoptosis in response to growth factor deprivation. However, the signal transduction pathways by which oxLDL induces [Ca(2+)](i) oscillations have not been elucidated. In this study, we show that these oscillations are mediated in part by intracellular mechanisms, as depleting extracellular Ca(2+) did not completely abolish the effect. Inhibiting sarco-endoplasmic reticulum ATPase (SERCA) completely blocked [Ca(2+)](i) oscillations, suggesting a role for Ca(2+) reuptake by the ER. The addition of oxLDL resulted in an almost immediate activation of sphingosine kinase (SK), which can increase sphingosine-1-phosphate (S1P) levels by phosphorylating sphingosine. Moreover, S1P was shown to be as effective as oxLDL in blocking macrophage apoptosis and producing [Ca(2+)](i) oscillations. This suggests that the mechanism in which oxLDL generates [Ca(2+)](i) oscillations may be 1) activation of SK, 2) SK-mediated increase in S1P levels, 3) S1P-mediated Ca(2+) release from intracellular stores, and 4) SERCA-mediated Ca(2+) reuptake back into the ER.
Collapse
Affiliation(s)
- Johnny H Chen
- Department of Medicine, University of British Columbia, Vancouver, Canada
| | | | | | | | | | | |
Collapse
|
44
|
Elsegood CL, Chang M, Jessup W, Scholz GM, Hamilton JA. Glucose metabolism is required for oxidized LDL-induced macrophage survival: role of PI3K and Bcl-2 family proteins. Arterioscler Thromb Vasc Biol 2009; 29:1283-9. [PMID: 19667115 DOI: 10.1161/atvbaha.108.180778] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
OBJECTIVE Oxidized low-density lipoprotein (oxLDL) induces survival of colony stimulating factor-1 (CSF-1)-dependent macrophages in vitro. Because atherosclerotic lesion-associated macrophages take up large amounts of glucose, we investigated whether, and how, oxLDL promotes glucose uptake and how glucose metabolism regulates oxLDL-induced macrophage survival. METHODS AND RESULTS OxLDL-induced macrophage survival required glucose metabolism. OxLDL stimulated 2 phases of glucose uptake, namely acute and chronic, which required PI3K but not MEK1/2 activity. PI3K appeared to regulate glucose transport via glucose transporter affinity and/or mobilization. OxLDL also maintained levels of the prosurvival proteins, Bcl-2 and Bcl-x(L), after CSF-1 had been removed through a combination of mechanisms including transcription, translation, and protein stabilization. Significantly, inhibition of glucose metabolism reduced Bcl-2 and Bcl-x(L) protein levels. MEK1/2 and PI3K activities were also required for oxLDL-induced Bcl-2 and Bcl-x(L) mRNA upregulation. CONCLUSIONS These results suggest that oxLDL enhances macrophage survival in the absence of CSF-1 by inducing PI3K-dependent glucose uptake, which is metabolized to maintain Bcl-2 and Bcl-x(L) protein levels.
Collapse
Affiliation(s)
- Caryn L Elsegood
- Arthritis and Inflammation Research Centre and Cooperative Research Centre for Chronic Inflammatory Diseases, Department of Medicine, The University of Melbourne, Royal Melbourne Hospital, Parkville, Australia
| | | | | | | | | |
Collapse
|
45
|
Abstract
Acid sphingomyelinase occupies a prominent position in sphingolipid catabolism, catalyzing the hydrolysis of sphingomyelin to ceramide and phosphorylcholine. Enzymatic dysfunction of acid sphingomyelinase results in Niemann-Pick disease, a lysosomal storage disorder characterized at the cellular level by accumulation of sphingomyelin within the endo-lysosomal compartment. Over the past decade interest in the role of acid sphingomyelinase has moved beyond its "housekeeping" function in constitutive turnover of sphingomyelin in the lysosome to include study of regulated ceramide generation. Ceramide functions as a bioactive sphingolipid with pleiotropic signaling properties, and has been implicated in diverse cellular processes of physiologic and pathophysiologic importance. Though many cellular enzymes have the capacity to generate ceramide,there is growing appreciation that "all ceramides are not created equal." Ceramides likely exert distinct effects in different cellular/subcellular compartments by virtue of access to other sphingolipid enzymes (e.g.ceramidases), effector molecules (e.g. ceramide-activated protein phosphatases), and neighboring lipids and proteins (e.g. cholesterol, ion channels). One of the unique features of acid sphingomyelinase is that it has been implicated in the hydrolysis of sphingomyelin in three different settings--the endo-lysosomal compartment,the outer leaflet of the plasma membrane, and lipoproteins. How a single gene product has the capacity to function in these diverse settings, and the subsequent impact on downstream ceramide-mediated biology is the subject of this review.
Collapse
Affiliation(s)
- Russell W Jenkins
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA.
| | | | | |
Collapse
|
46
|
Schaeffer DF, Riazy M, Parhar KS, Chen JH, Duronio V, Sawamura T, Steinbrecher UP. LOX-1 augments oxLDL uptake by lysoPC-stimulated murine macrophages but is not required for oxLDL clearance from plasma. J Lipid Res 2009; 50:1676-84. [PMID: 19359704 DOI: 10.1194/jlr.m900167-jlr200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Oxidized LDL (oxLDL) promotes lipid accumulation as well as growth and survival signaling in macrophages. OxLDL uptake is mainly due to scavenger receptors SR-AI/II and CD36. However, other scavenger receptors such as lectin-like oxLDL receptor-1 (LOX-1) may also play a role. We used mice with targeted inactivation of the LOX-1 gene to define the role of this receptor in the uptake of oxLDL and in activation of survival pathways. There was no difference in uptake or degradation of 125I-oxLDL in unstimulated macrophages from wild-type and LOX-1 knockout mice and no difference in the rate of clearance of oxLDL from plasma in vivo. However, when expression of LOX-1 was induced with lysophosphatidylcholine, oxLDL uptake and degradation increased 2-fold in wild-type macrophages but did not change in LOX-1 knockout macrophages. Macrophages lacking LOX-1 showed the same stimulation of PKB phosphorylation and enhancement of survival by oxLDL as wild-type cells. These data show that LOX-1 does not alter the uptake of oxLDL in unstimulated macrophages and is not essential for the pro-survival effect of oxLDL in these cells. However, LOX-1 expression is highly inducible by lysophosphatidylcholine and pro-inflammatory cytokines, and if that occurred in macrophages within atheromas, LOX-1 could substantially increase oxLDL uptake by lesion macrophages.
Collapse
Affiliation(s)
- David F Schaeffer
- Department of Medicine, University of British Columbia, Vancouver, Canada
| | | | | | | | | | | | | |
Collapse
|
47
|
Harangi M, Szodoray P, Paragh G. Atherosclerosis: a complex interplay of inflammatory processes. ACTA ACUST UNITED AC 2009. [DOI: 10.2217/clp.09.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
48
|
Chen JH, Riazy M, Smith EM, Proud CG, Steinbrecher UP, Duronio V. Oxidized LDL-Mediated Macrophage Survival Involves Elongation Factor-2 Kinase. Arterioscler Thromb Vasc Biol 2009; 29:92-8. [DOI: 10.1161/atvbaha.108.174599] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Johnny H. Chen
- From the Department of Medicine (J.H.C., M.R., U.P.S., V.D.), University of British Columbia, and Vancouver Coastal Health Research Institute, Vancouver, BC, Canada; Genome Damage and Stability Centre (E.M.S.), University of Sussex, Falmer, Brighton, UK; and the School of Biological Sciences (C.G.P.), University of Southampton, UK
| | - Maziar Riazy
- From the Department of Medicine (J.H.C., M.R., U.P.S., V.D.), University of British Columbia, and Vancouver Coastal Health Research Institute, Vancouver, BC, Canada; Genome Damage and Stability Centre (E.M.S.), University of Sussex, Falmer, Brighton, UK; and the School of Biological Sciences (C.G.P.), University of Southampton, UK
| | - Ewan M. Smith
- From the Department of Medicine (J.H.C., M.R., U.P.S., V.D.), University of British Columbia, and Vancouver Coastal Health Research Institute, Vancouver, BC, Canada; Genome Damage and Stability Centre (E.M.S.), University of Sussex, Falmer, Brighton, UK; and the School of Biological Sciences (C.G.P.), University of Southampton, UK
| | - Christopher G. Proud
- From the Department of Medicine (J.H.C., M.R., U.P.S., V.D.), University of British Columbia, and Vancouver Coastal Health Research Institute, Vancouver, BC, Canada; Genome Damage and Stability Centre (E.M.S.), University of Sussex, Falmer, Brighton, UK; and the School of Biological Sciences (C.G.P.), University of Southampton, UK
| | - Urs P. Steinbrecher
- From the Department of Medicine (J.H.C., M.R., U.P.S., V.D.), University of British Columbia, and Vancouver Coastal Health Research Institute, Vancouver, BC, Canada; Genome Damage and Stability Centre (E.M.S.), University of Sussex, Falmer, Brighton, UK; and the School of Biological Sciences (C.G.P.), University of Southampton, UK
| | - Vincent Duronio
- From the Department of Medicine (J.H.C., M.R., U.P.S., V.D.), University of British Columbia, and Vancouver Coastal Health Research Institute, Vancouver, BC, Canada; Genome Damage and Stability Centre (E.M.S.), University of Sussex, Falmer, Brighton, UK; and the School of Biological Sciences (C.G.P.), University of Southampton, UK
| |
Collapse
|
49
|
Abstract
The activation of PI3K (phosphoinositide 3-kinase) family members is a universal event in response to virtually all cytokines, growth factors and hormones. As a result of formation of PtdIns with an added phosphate at the 3 position of the inositol ring, activation of the protein kinases PDK1 (phosphoinositide-dependent kinase 1) and PKB (protein kinase B)/Akt occurs. The PI3K/PKB pathway impinges upon a remarkable array of intracellular events that influence either directly or indirectly whether or not a cell will undergo apoptosis. In this review, the many ways in which PI3K/PKB can control these processes are summarized. Not all of the events described will necessarily play a role in any one cell type, but a subset of these events is probably essential for the survival of every cell.
Collapse
|
50
|
Ceramide 1-phosphate (C1P) promotes cell migration Involvement of a specific C1P receptor. Cell Signal 2008; 21:405-12. [PMID: 19041940 DOI: 10.1016/j.cellsig.2008.11.003] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2008] [Accepted: 11/08/2008] [Indexed: 01/27/2023]
Abstract
Ceramide 1-phosphate (C1P) is a bioactive sphingolipid that is implicated in the regulation of cell homeostasis and the control of inflammation. It is mitogenic for fibroblasts and macrophages, and has been described as potent inhibitor of apoptosis. Using RAW 264.7 macrophages we have now discovered a new biological activity of C1P: stimulation of cell migration. This novel action can only be observed when C1P is applied exogenously to the cells in culture, and not by increasing the intracellular levels of C1P. This fact led to identify a specific receptor through which C1P stimulates cell migration. The receptor is coupled to G(i) proteins and causes phosphorylation of extracellularly regulated kinases 1 and 2, and protein kinase B (also known as Akt) upon ligation with C1P. Inhibition of either of these pathways completely abolished C1P-stimulated macrophage migration. In addition, C1P stimulated the DNA binding activity of nuclear factor kappa B, and blockade of this transcription factor resulted in complete inhibition of macrophage migration. This newly identified receptor could be an important drug target for treatment of illnesses that are associated to inflammatory processes, or to diseases in which cell migration is a major cause of pathology, as it occurs in metastatic tumors.
Collapse
|