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Zhang H, Wang J, Sun J, Wang Q, Guo L, Ju X. Regulatory mechanism underlying liver X receptor effects on the tumor microenvironment, inflammation and tumorigenesis. Expert Opin Ther Targets 2023; 27:989-998. [PMID: 37753584 DOI: 10.1080/14728222.2023.2264513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Accepted: 09/25/2023] [Indexed: 09/28/2023]
Abstract
INTRODUCTION Liver X receptors (LXRs) have emerged as novel targets for tumor treatment. LXRs within the tumor microenvironment show the capacity to impact tumorigenesis and tumor development by regulating the infiltration of immune cells and release of cytokines to moderate inflammation. AREAS COVERED In this review, we present a systematic description of recent progress in understanding the impact of LXRs on the tumor microenvironment and tumorigenesis. We also summarize the antitumor effects mediated by LXRs via their regulation of cytokine expression. Additionally, we discuss the limitations of LXR research in tumor studies to date. EXPERT OPINION Previous studies have demonstrated abnormal LXR expression in tumor tissues, and activation of LXRs has been shown to inhibit tumorigenesis and promote apoptosis in tumor cells. However, LXRs can also affect tumorigenesis by regulating immune cell functions within the tumor immune microenvironment. By summarizing the impact of LXRs on immune cells, we provide new insights into the multifaceted nature of LXRs as antitumor targets.
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Affiliation(s)
- Heng Zhang
- Department of General Surgery, Nanjing Lishui District People's Hospital, Zhongda Hospital Lishui Branch, Southeast University, Nanjing, China
| | - Jing Wang
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Jiang Sun
- School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Qiang Wang
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Lanfang Guo
- Department of Clinical Laboratory Medicine, The Fourth People's Hospital of Jiangsu University, Zhenjiang, Jiangsu, China
| | - Xiaoli Ju
- School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, China
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de la Aleja AG, Herrero C, Torres-Torresano M, Schiaffino MT, Del Castillo A, Alonso B, Vega MA, Puig-Kröger A, Castrillo A, Corbí ÁL. Inhibition of LXR controls the polarization of human inflammatory macrophages through upregulation of MAFB. Cell Mol Life Sci 2023; 80:96. [PMID: 36930354 PMCID: PMC10020776 DOI: 10.1007/s00018-023-04745-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/03/2023] [Accepted: 03/01/2023] [Indexed: 03/18/2023]
Abstract
Monocyte-derived macrophages contribute to pathogenesis in inflammatory diseases and their effector functions greatly depend on the prevailing extracellular milieu. Whereas M-CSF primes macrophages for acquisition of an anti-inflammatory profile, GM-CSF drives the generation of T cell-stimulatory and pro-inflammatory macrophages. Liver X Receptors (LXRα and LXRβ) are nuclear receptors that control cholesterol metabolism and regulate differentiation of tissue-resident macrophages. Macrophages from rheumatoid arthritis and other inflammatory pathologies exhibit an enriched LXR pathway, and recent reports have shown that LXR activation raises pro-inflammatory effects and impairs the acquisition of the anti-Inflammatory profile of M-CSF-dependent monocyte-derived macrophages (M-MØ). We now report that LXR inhibition prompts the acquisition of an anti-inflammatory gene and functional profile of macrophages generated within a pathological environment (synovial fluid from Rheumatoid Arthritis patients) as well as during the GM-CSF-dependent differentiation of human monocyte-derived macrophages (GM-MØ). Mechanistically, inhibition of LXR results in macrophages with higher expression of the v-Maf Avian Musculoaponeurotic Fibrosarcoma Oncogene Homolog B (MAFB) transcription factor, which governs the macrophage anti-inflammatory profile, as well as over-expression of MAFB-regulated genes. Indeed, gene silencing experiments on human macrophages evidenced that MAFB is required for the LXR inhibitor to enhance the anti-inflammatory nature of human macrophages. As a whole, our results demonstrate that LXR inhibition prompts the acquisition of an anti-inflammatory transcriptional and functional profile of human macrophages in a MAFB-dependent manner, and propose the use of LXR antagonists as potential therapeutic alternatives in macrophage re-programming strategies during inflammatory responses.
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Affiliation(s)
- Arturo González de la Aleja
- Myeloid Cell Laboratory, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Cristina Herrero
- Myeloid Cell Laboratory, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Mónica Torres-Torresano
- Unidad de Inmuno-Metabolismo e Inflamación, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Hospital General Universitario Gregorio Marañón, Madrid, Spain
| | - María Teresa Schiaffino
- Unidad de Inmuno-Metabolismo e Inflamación, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Hospital General Universitario Gregorio Marañón, Madrid, Spain
| | - Alejandro Del Castillo
- Myeloid Cell Laboratory, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Bárbara Alonso
- Myeloid Cell Laboratory, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Miguel A Vega
- Myeloid Cell Laboratory, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Amaya Puig-Kröger
- Unidad de Inmuno-Metabolismo e Inflamación, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Hospital General Universitario Gregorio Marañón, Madrid, Spain
| | - Antonio Castrillo
- Unidad de Biomedicina (Unidad Asociada al CSIC), Instituto Universitario de Investigaciones Biomédicas y Sanitarias (IUIBS), Grupo de Investigación Medio Ambiente y Salud, Universidad de Las Palmas de Gran Canaria, Las Palmas, Spain
- Instituto Investigaciones Biomédicas "Alberto Sols" (IIBM), Centro Mixto Consejo Superior de Investigaciones Científicas y Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
| | - Ángel L Corbí
- Myeloid Cell Laboratory, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain.
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Findeisen HM, Voges VC, Braun LC, Sonnenberg J, Schwarz D, Körner H, Reinecke H, Sohrabi Y. LXRα Regulates oxLDL-Induced Trained Immunity in Macrophages. Int J Mol Sci 2022; 23:ijms23116166. [PMID: 35682840 PMCID: PMC9181299 DOI: 10.3390/ijms23116166] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 05/26/2022] [Accepted: 05/26/2022] [Indexed: 12/19/2022] Open
Abstract
Reprogramming of metabolic pathways in monocytes and macrophages can induce a proatherosclerotic inflammatory memory called trained innate immunity. Here, we have analyzed the role of the Liver X receptor (LXR), a crucial regulator of metabolism and inflammation, in oxidized low-density lipoprotein (oxLDL)-induced trained innate immunity. Human monocytes were incubated with LXR agonists, antagonists, and oxLDL for 24 h. After five days of resting time, cells were restimulated with the TLR-2 agonist Pam3cys. OxLDL priming induced the expression of LXRα but not LXRβ. Pharmacologic LXR activation was enhanced, while LXR inhibition prevented the oxLDL-induced inflammatory response. Furthermore, LXR inhibition blocked the metabolic changes necessary for epigenetic reprogramming associated with trained immunity. In fact, enrichment of activating histone marks at the IL-6 and TNFα promotor was reduced following LXR inhibition. Based on the differential expression of the LXR isoforms, we inhibited LXRα and LXRβ genes using siRNA in THP1 cells. As expected, siRNA-mediated knock-down of LXRα blocked the oxLDL-induced inflammatory response, while knock-down of LXRβ had no effect. We demonstrate a specific and novel role of the LXRα isoform in the regulation of oxLDL-induced trained immunity. Our data reveal important aspects of LXR signaling in innate immunity with relevance to atherosclerosis formation.
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González de la Aleja A, Herrero C, Torres-Torresano M, de la Rosa JV, Alonso B, Capa-Sardón E, Muller IB, Jansen G, Puig-Kröger A, Vega MA, Castrillo A, Corbí ÁL. Activation of LXR Nuclear Receptors Impairs the Anti-Inflammatory Gene and Functional Profile of M-CSF-Dependent Human Monocyte-Derived Macrophages. Front Immunol 2022; 13:835478. [PMID: 35280993 PMCID: PMC8907538 DOI: 10.3389/fimmu.2022.835478] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 02/07/2022] [Indexed: 12/30/2022] Open
Abstract
Liver X Receptors (LXR) control cholesterol metabolism and exert anti-inflammatory actions but their contribution to human macrophage polarization remains unclear. The LXR pathway is enriched in pro-inflammatory macrophages from rheumatoid arthritis as well as in tumors-associated macrophages from human tumors. We now report that LXR activation inhibits the anti-inflammatory gene and functional profile of M-CSF-dependent human macrophages, and prompts the acquisition of a pro-inflammatory gene signature, with both effects being blocked by an LXR inverse agonist. Mechanistically, the LXR-stimulated macrophage polarization shift correlates with diminished expression of MAFB and MAF, which govern the macrophage anti-inflammatory profile, and with enhanced release of activin A. Indeed, LXR activation impaired macrophage polarization in response to tumor-derived ascitic fluids, as well as the expression of MAF- and MAFB-dependent genes. Our results demonstrate that LXR activation limits the anti-inflammatory human macrophage polarization and prompts the acquisition of an inflammatory transcriptional and functional profile.
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Affiliation(s)
- Arturo González de la Aleja
- Myeloid Cell Laboratory, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Cristina Herrero
- Myeloid Cell Laboratory, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Mónica Torres-Torresano
- Unidad de Inmuno-Metabolismo e Inflamación, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain
| | - Juan Vladimir de la Rosa
- Unidad de Biomedicina (Unidad Asociada al Consejo Superior de Investigaciones Científicas (CSIC)), Instituto Universitario de Investigaciones Biomédicas y Sanitarias (IUIBS), Grupo de Investigación Medio Ambiente y Salud, Universidad de Las Palmas de Gran Canaria, Las Palmas, Spain
| | - Bárbara Alonso
- Myeloid Cell Laboratory, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Enrique Capa-Sardón
- Myeloid Cell Laboratory, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Ittai B. Muller
- Department of Clinical Chemistry, Amsterdam University Medical Center, Location VUmc, Amsterdam, Netherlands
| | - Gerrit Jansen
- Department of Rheumatology and Clinical Immunology, Amsterdam University Medical Center, Location VUmc, Amsterdam, Netherlands
| | - Amaya Puig-Kröger
- Unidad de Inmuno-Metabolismo e Inflamación, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain
| | - Miguel A. Vega
- Myeloid Cell Laboratory, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Antonio Castrillo
- Unidad de Biomedicina (Unidad Asociada al Consejo Superior de Investigaciones Científicas (CSIC)), Instituto Universitario de Investigaciones Biomédicas y Sanitarias (IUIBS), Grupo de Investigación Medio Ambiente y Salud, Universidad de Las Palmas de Gran Canaria, Las Palmas, Spain
- Instituto Investigaciones Biomédicas “Alberto Sols” (IIBM), and Centro Mixto Consejo Superior de Investigaciones Científicas y Universidad Autónoma de Madrid (Consejo Superior de Investigaciones Científicas (ICSIC)-UAM), Madrid, Spain
| | - Ángel L. Corbí
- Myeloid Cell Laboratory, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
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5
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Li B, Lian M, Li Y, Qian Q, Zhang J, Liu Q, Tang R, Ma X. Myeloid-Derived Suppressive Cells Deficient in Liver X Receptor α Protected From Autoimmune Hepatitis. Front Immunol 2021; 12:732102. [PMID: 34512667 PMCID: PMC8427166 DOI: 10.3389/fimmu.2021.732102] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 08/05/2021] [Indexed: 11/13/2022] Open
Abstract
Myeloid-derived suppressor cells (MDSCs) emerge as a promising candidate for the immunotherapy of autoimmune hepatitis (AIH). However, targets for modulating MDSC in AIH are still being searched. Liver X receptors (LXRs) are important nuclear receptors linking lipid metabolism and immune responses. Despite the extensive studies of LXR in myeloid compartment, its role in MDSCs is currently less understood. Herein, expression of LXRα was found to be upregulated in AIH patients and colocalized with hepatic MDSCs. In ConA-induced hepatitis, deletion of LXRα led to increased expansion of MDSCs in the liver and alleviated the hepatic injury. MDSCs in LXRα-/- mice exhibited enhanced proliferation and survival comparing with WT mice. T-cell proliferation assay and adoptive cell transfer experiment validated the potent immunoregulatory role of MDSCs in vitro and in vivo. Mechanistically, MDSCs from LXRα-/- mice possessed significantly lower expression of interferon regulatory factor 8 (IRF-8), a key negative regulator of MDSC differentiation. Transcriptional activation of IRF-8 by LXRα was further demonstrated. Conclusion We reported that abrogation of LXRα facilitated the expansion of MDSCs via downregulating IRF-8, and thereby ameliorated hepatic immune injury profoundly. Our work highlights the therapeutic potential of targeting LXRα in AIH.
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Affiliation(s)
| | | | | | | | | | | | | | - Xiong Ma
- *Correspondence: Xiong Ma, ; Ruqi Tang,
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Mai CT, Zheng DC, Li XZ, Zhou H, Xie Y. Liver X receptors conserve the therapeutic target potential for the treatment of rheumatoid arthritis. Pharmacol Res 2021; 170:105747. [PMID: 34186192 DOI: 10.1016/j.phrs.2021.105747] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 06/21/2021] [Accepted: 06/24/2021] [Indexed: 01/03/2023]
Abstract
Rheumatoid arthritis (RA) is a chronic multi-system autoimmune disease with extremely complex pathogenesis. Significantly altered lipid paradox related to the inflammatory burden is reported in RA patients, inducing 50% higher cardiovascular risks. Recent studies have also demonstrated that lipid metabolism can regulate many functions of immune cells in which metabolic pathways have altered. The nuclear liver X receptors (LXRs), including LXRα and LXRβ, play a central role in regulating lipid homeostasis and inflammatory responses. Undoubtedly, LXRs have been considered as an attractive therapeutic target for the treatment of RA. However, there are some contradictory effects of LXRs agonists observed in previous animal studies where both pro-inflammatory role and anti-inflammatory role were revealed for LXRs activation in RA. Therefore, in addition to updating the knowledge of LXRs as the prominent regulators of lipid homeostasis, the purpose of this review is to summarize the effects of LXRs agonists in RA-associated immune cells, to explore the underlying reasons for the contradictory therapeutic effects of LXRs agonists observed in RA animal models, and to discuss future strategy for the treatment of RA with LXRs modulators.
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Affiliation(s)
- Chu-Tian Mai
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Taipa, Macau; Faculty of Chinese Medicines, Macau University of Science and Technology, Taipa, Macau
| | - De-Chong Zheng
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Taipa, Macau; Faculty of Chinese Medicines, Macau University of Science and Technology, Taipa, Macau
| | - Xin-Zhi Li
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Taipa, Macau
| | - Hua Zhou
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Taipa, Macau; Faculty of Chinese Medicines, Macau University of Science and Technology, Taipa, Macau
| | - Ying Xie
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Taipa, Macau.
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Cholesterol metabolism: a new molecular switch to control inflammation. Clin Sci (Lond) 2021; 135:1389-1408. [PMID: 34086048 PMCID: PMC8187928 DOI: 10.1042/cs20201394] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 05/14/2021] [Accepted: 05/17/2021] [Indexed: 12/30/2022]
Abstract
The immune system protects the body against harm by inducing inflammation. During the immune response, cells of the immune system get activated, divided and differentiated in order to eliminate the danger signal. This process relies on the metabolic reprogramming of both catabolic and anabolic pathways not only to produce energy in the form of ATP but also to generate metabolites that exert key functions in controlling the response. Equally important to mounting an appropriate effector response is the process of immune resolution, as uncontrolled inflammation is implicated in the pathogenesis of many human diseases, including allergy, chronic inflammation and cancer. In this review, we aim to introduce the reader to the field of cholesterol immunometabolism and discuss how both metabolites arising from the pathway and cholesterol homeostasis are able to impact innate and adaptive immune cells, staging cholesterol homeostasis at the centre of an adequate immune response. We also review evidence that demonstrates the clear impact that cholesterol metabolism has in both the induction and the resolution of the inflammatory response. Finally, we propose that emerging data in this field not only increase our understanding of immunometabolism but also provide new tools for monitoring and intervening in human diseases, where controlling and/or modifying inflammation is desirable.
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Sun Y, Zhou L, Chen W, Zhang L, Zeng H, Sun Y, Long J, Yuan D. Immune metabolism: a bridge of dendritic cells function. Int Rev Immunol 2021; 41:313-325. [PMID: 33792460 DOI: 10.1080/08830185.2021.1897124] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
An increasing number of researches have shown that cell metabolism regulates cell function. Dendritic cells (DCs), a professional antigen presenting cells, connect innate and adaptive immune responses. The preference of DCs for sugar or lipid affects its phenotypes and functions. In many diseases such as atherosclerosis (AS), diabetes mellitus and tumor, altered glucose or lipid level in microenvironment makes DCs exert ineffective or opposite immune roles, which accelerates the development of these diseases. In this article, we review the metabolism pathways of glucose and cholesterol in DCs, and the effects of metabolic changes on the phenotype and function of DCs. In addition, we discuss the effects of changes in glucose and lipid levels on DCs in the context of different diseases for better understanding the relationship between DCs and diseases. The immune metabolism of DCs may be a potential intervention link to treat metabolic-related immune diseases.
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Affiliation(s)
- Yuting Sun
- School of Pharmacy, Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, People's Republic of China
| | - Liyu Zhou
- School of Pharmacy, Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, People's Republic of China
| | - Weikai Chen
- School of Pharmacy, Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, People's Republic of China
| | - Linhui Zhang
- School of Pharmacy, Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, People's Republic of China
| | - Hongbo Zeng
- School of Pharmacy, Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, People's Republic of China
| | - Yunxia Sun
- Jiangsu Province Hospital of TCM, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, People's Republic of China
| | - Jun Long
- School of Pharmacy, Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, People's Republic of China
| | - Dongping Yuan
- School of Pharmacy, Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, People's Republic of China
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Kim BY, Son Y, Cho HR, Lee D, Eo SK, Kim K. 27-Hydroxycholesterol induces macrophage gene expression via LXR-dependent and -independent mechanisms. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2021; 25:111-118. [PMID: 33602881 PMCID: PMC7893494 DOI: 10.4196/kjpp.2021.25.2.111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 09/24/2020] [Accepted: 12/22/2020] [Indexed: 12/26/2022]
Abstract
27-Hydroxycholesterol (27OHChol) exhibits agonistic activity for liver X receptors (LXRs). To determine roles of the LXR agonistic activity in macrophage gene expression, we investigated the effects of LXR inhibition on the 27OHChol-induced genes. Treatment of human THP-1 cells with GSK 2033, a potent cell-active LXR antagonist, results in complete inhibition in the transcription of LXR target genes (such as LXRα and ABCA1) induced by 27OHChol or a synthetic LXR ligand TO 901317. Whereas expression of CCL2 and CCL4 remains unaffected by GSK 2033, TNF-α expression is further induced and 27OHChol-induced CCL3 and CXCL8 genes are suppressed at both the transcriptional and protein translation levels in the presence of GSK 2033. This LXR antagonist downregulates transcript levels and surface expression of CD163 and CD206 and suppresses the transcription of CD14, CD80, and CD86 genes without downregulating their surface levels. GSK 2033 alone had no effect on the basal expression levels of the aforementioned genes. Collectively, these results indicate that LXR inhibition leads to differential regulation of 27-hydroxycholesterol-induced genes in macrophages. We propose that 27OHChol induces gene expression and modulates macrophage functions via LXR-dependent and -independent mechanisms.
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Affiliation(s)
- Bo-Young Kim
- Department of Pharmacology, School of Medicine, Pusan National University, Yangsan 50612, Korea
| | - Yonghae Son
- Department of Pharmacology, School of Medicine, Pusan National University, Yangsan 50612, Korea
| | - Hyok-Rae Cho
- Department of Neurosurgery, Kosin University College of Medicine, Busan 49267, Korea
| | - Dongjun Lee
- Department of Convergence Medicine, School of Medicine, Pusan National University, Yangsan 50612, Korea
| | - Seong-Kug Eo
- College of Veterinary Medicine and Bio-Safety Research Institute, Jeonbuk National University, Iksan 54596, Korea
| | - Koanhoi Kim
- Department of Pharmacology, School of Medicine, Pusan National University, Yangsan 50612, Korea
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Alatshan A, Benkő S. Nuclear Receptors as Multiple Regulators of NLRP3 Inflammasome Function. Front Immunol 2021; 12:630569. [PMID: 33717162 PMCID: PMC7952630 DOI: 10.3389/fimmu.2021.630569] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 02/08/2021] [Indexed: 12/11/2022] Open
Abstract
Nuclear receptors are important bridges between lipid signaling molecules and transcription responses. Beside their role in several developmental and physiological processes, many of these receptors have been shown to regulate and determine the fate of immune cells, and the outcome of immune responses under physiological and pathological conditions. While NLRP3 inflammasome is assumed as key regulator for innate and adaptive immune responses, and has been associated with various pathological events, the precise impact of the nuclear receptors on the function of inflammasome is hardly investigated. A wide variety of factors and conditions have been identified as modulators of NLRP3 inflammasome activation, and at the same time, many of the nuclear receptors are known to regulate, and interact with these factors, including cellular metabolism and various signaling pathways. Nuclear receptors are in the focus of many researches, as these receptors are easy to manipulate by lipid soluble molecules. Importantly, nuclear receptors mediate regulatory mechanisms at multiple levels: not only at transcription level, but also in the cytosol via non-genomic effects. Their importance is also reflected by the numerous approved drugs that have been developed in the past decade to specifically target nuclear receptors subtypes. Researches aiming to delineate mechanisms that regulate NLRP3 inflammasome activation draw a wide range of attention due to their unquestionable importance in infectious and sterile inflammatory conditions. In this review, we provide an overview of current reports and knowledge about NLRP3 inflammasome regulation from the perspective of nuclear receptors, in order to bring new insight to the potentially therapeutic aspect in targeting NLRP3 inflammasome and NLRP3 inflammasome-associated diseases.
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Affiliation(s)
- Ahmad Alatshan
- Departments of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Molecular Cellular and Immune Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Szilvia Benkő
- Departments of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Molecular Cellular and Immune Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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Xie Y, Feng SL, Mai CT, Zheng YF, Wang H, Liu ZQ, Zhou H, Liu L. Suppression of up-regulated LXRα by silybin ameliorates experimental rheumatoid arthritis and abnormal lipid metabolism. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2021; 80:153339. [PMID: 33038868 DOI: 10.1016/j.phymed.2020.153339] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 08/21/2020] [Accepted: 09/07/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND As dysregulation of immunometabolism plays a key role in the immunological diseases, dyslipidemia frequently observed in rheumatoid arthritis (RA) patients (60%) is associated with the disease activity and has been considered as the potential target of anti-inflammatory strategy. However, targeting of metabolic events to develop novel anti-inflammatory therapeutics are far from clear as well as the mechanism of dyslipidemia in RA. PURPOSE To explore the therapeutic potential and mechanisms of silybin again RA through the regulation of lipid metabolism. METHODS Adjuvant-induced arthritis (AIA) rat model was used to examine the effects of silybin on modulating dysregulated lipid metabolism and arthritis. Metabolomics, docking technology, and biochemical methods such as western blots, qRT-PCR, immunofluorescence staining were performed to understanding the underlying mechanisms. Moreover, knock-down of LXRα and LXRα agonist were used on LO2 cell lines to understand the action of silybin. RESULTS We are the first to demonstrate that silybin can ameliorate dyslipidemia and arthritis in AIA rats. Overexpression of LXRα and several key lipogenic enzymes regulated by LXRα, including lipoprotein lipase (LPL), cholesterol 7α and 27α hydroxylase (CYP7A, CYP27A), adipocyte fatty acid-binding protein (aP2/FABP4) and fatty acid translocase (CD36/FAT), were observed in AIA rats, which mostly accounted for dyslipidemia during arthritis development. Metabolomics, docking technology, and biochemical results indicated that anti-arthritis effects of silybin related to suppressing the up-regulated LXRα and abnormal lipid metabolism. Notably, activation of LXRα could potentiate cell inflammatory process induced by LPS through the regulation of NF-κB pathway, however, suppression of LXRα agonism by siRNA or silybin reduced the nuclear translocation of NF-κB as well as the induction of downstream cytokines, indicating LXRα agonism is the important factor for the arthritis development and could be a potential target. CONCLUSION The up-regulation of LXRα can activate lipogenesis enzymes to worsen the inflammatory process in AIA rats as well as the development of dyslipidemia, therefore, rectifying lipid disorder via suppression of LXRα agonism pertains the capacity of drug target, which enables to discover and develop new drugs to treat rheumatoid arthritis with dyslipidaemia.
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Affiliation(s)
- Ying Xie
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Taipa, Macau SAR.
| | - Sen-Ling Feng
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Taipa, Macau SAR
| | - Chu-Tian Mai
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Taipa, Macau SAR
| | - Yan-Fang Zheng
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Taipa, Macau SAR
| | - Hui Wang
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Taipa, Macau SAR
| | - Zhong-Qiu Liu
- International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, P. R. China
| | - Hua Zhou
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Taipa, Macau SAR
| | - Liang Liu
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Taipa, Macau SAR.
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12
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Pineda-Torra I, Siddique S, Waddington KE, Farrell R, Jury EC. Disrupted Lipid Metabolism in Multiple Sclerosis: A Role for Liver X Receptors? Front Endocrinol (Lausanne) 2021; 12:639757. [PMID: 33927692 PMCID: PMC8076792 DOI: 10.3389/fendo.2021.639757] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 03/22/2021] [Indexed: 12/20/2022] Open
Abstract
Multiple sclerosis (MS) is a chronic neurological disease driven by autoimmune, inflammatory and neurodegenerative processes leading to neuronal demyelination and subsequent degeneration. Systemic lipid metabolism is disturbed in people with MS, and lipid metabolic pathways are crucial to the protective process of remyelination. The lipid-activated transcription factors liver X receptors (LXRs) are important integrators of lipid metabolism and immunity. Consequently, there is a strong interest in targeting these receptors in a number of metabolic and inflammatory diseases, including MS. We have reviewed the evidence for involvement of LXR-driven lipid metabolism in the dysfunction of peripheral and brain-resident immune cells in MS, focusing on human studies, both the relapsing remitting and progressive phases of the disease are discussed. Finally, we discuss the therapeutic potential of modulating the activity of these receptors with existing pharmacological agents and highlight important areas of future research.
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Affiliation(s)
- Inés Pineda-Torra
- Centre for Cardiometabolic and Vascular Medicine, Department of Medicine, University College London, London, United Kingdom
- *Correspondence: Elizabeth C. Jury, ; Inés Pineda-Torra,
| | - Sherrice Siddique
- Centre for Rheumatology, Department of Medicine, University College London, London, United Kingdom
| | - Kirsty E. Waddington
- Centre for Cardiometabolic and Vascular Medicine, Department of Medicine, University College London, London, United Kingdom
- Centre for Rheumatology, Department of Medicine, University College London, London, United Kingdom
| | - Rachel Farrell
- Department of Neuroinflammation, Institute of Neurology and National Hospital of Neurology and Neurosurgery, University College London, London, United Kingdom
| | - Elizabeth C. Jury
- Centre for Rheumatology, Department of Medicine, University College London, London, United Kingdom
- *Correspondence: Elizabeth C. Jury, ; Inés Pineda-Torra,
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13
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Zhao L, Lei W, Deng C, Wu Z, Sun M, Jin Z, Song Y, Yang Z, Jiang S, Shen M, Yang Y. The roles of liver X receptor α in inflammation and inflammation-associated diseases. J Cell Physiol 2020; 236:4807-4828. [PMID: 33305467 DOI: 10.1002/jcp.30204] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 10/19/2020] [Accepted: 11/24/2020] [Indexed: 12/14/2022]
Abstract
Liver X receptor α (LXRα; also known as NR1H3), an isoform of LXRs, is a member of the nuclear receptor family of transcription factors and plays essential roles in the transcriptional control of cholesterol homeostasis. Previous in-depth phenotypic analyses of mouse models with deficient LXRα have also demonstrated various physiological functions of this receptor within inflammatory responses. LXRα activation exerts a combination of metabolic and anti-inflammatory actions resulting in the modulation and the amelioration of inflammatory disorders. The tight "repercussions" between LXRα and inflammation, as well as cholesterol homeostasis, have suggested that LXRα could be pharmacologically targeted in pathologies such as atherosclerosis, acute lung injury, and Alzheimer's disease. This review gives an overview of the recent advances in understanding the roles of LXRα in inflammation and inflammation-associated diseases, which will help in the design of future experimental researches on the potential of LXRα and advance the investigation of LXRα as pharmacological inflammatory targets.
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Affiliation(s)
- Lin Zhao
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education Life of Sciences, Northwest University, Xi'an, China.,Department of Cardiovascular Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Wangrui Lei
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education Life of Sciences, Northwest University, Xi'an, China
| | - Chao Deng
- Department of Cardiovascular Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Zhen Wu
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education Life of Sciences, Northwest University, Xi'an, China
| | - Meng Sun
- Department of Cardiology, The First Hospital of Shanxi Medical University, Taiyuan, China
| | - Zhenxiao Jin
- Department of Cardiovascular Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Yanbin Song
- Department of Cardiology, Affiliated Hospital, Yan'an University, China
| | - Zhi Yang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education Life of Sciences, Northwest University, Xi'an, China
| | - Shuai Jiang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education Life of Sciences, Northwest University, Xi'an, China
| | - Mingzhi Shen
- Hainan Hospital of PLA General Hospital, The Second School of Clinical Medicine, Southern Medical University, Sanya, Hainan, China.,Hainan Branch of National Clinical Reasearch Center of Geriatrics Disease, Sanya, Hainan, China
| | - Yang Yang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education Life of Sciences, Northwest University, Xi'an, China
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14
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Glaría E, Letelier NA, Valledor AF. Integrating the roles of liver X receptors in inflammation and infection: mechanisms and outcomes. Curr Opin Pharmacol 2020; 53:55-65. [PMID: 32599447 DOI: 10.1016/j.coph.2020.05.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 05/15/2020] [Accepted: 05/18/2020] [Indexed: 01/10/2023]
Abstract
Liver X receptors (LXRs) are transcription factors from the nuclear receptor family that can be pharmacologically activated by high-affinity agonists. LXR activation exerts a combination of metabolic and anti-inflammatory actions that result in the modulation of immune responses and in the amelioration of inflammatory disorders. In addition, LXR agonists modulate the metabolism of infected cells and limit the infectivity and/or growth of several pathogens. This review gives an overview of the recent advances in understanding the complexity of the mechanisms through which the LXR pathway controls inflammation and host-cell pathogen interaction.
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Affiliation(s)
- Estibaliz Glaría
- Department of Cell Biology, Physiology and Immunology, School of Biology, University of Barcelona, 08028 Barcelona, Spain; Institute of Biomedicine of the University of Barcelona (IBUB), 08028 Barcelona, Spain
| | - Nicole A Letelier
- Department of Cell Biology, Physiology and Immunology, School of Biology, University of Barcelona, 08028 Barcelona, Spain; Institute of Biomedicine of the University of Barcelona (IBUB), 08028 Barcelona, Spain
| | - Annabel F Valledor
- Department of Cell Biology, Physiology and Immunology, School of Biology, University of Barcelona, 08028 Barcelona, Spain; Institute of Biomedicine of the University of Barcelona (IBUB), 08028 Barcelona, Spain.
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15
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Ménégaut L, Thomas C, Jalil A, Julla JB, Magnani C, Ceroi A, Basmaciyan L, Dumont A, Le Goff W, Mathew MJ, Rébé C, Dérangère V, Laubriet A, Crespy V, Pais de Barros JP, Steinmetz E, Venteclef N, Saas P, Lagrost L, Masson D. Interplay between Liver X Receptor and Hypoxia Inducible Factor 1α Potentiates Interleukin-1β Production in Human Macrophages. Cell Rep 2020; 31:107665. [DOI: 10.1016/j.celrep.2020.107665] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 01/09/2020] [Accepted: 04/28/2020] [Indexed: 11/16/2022] Open
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16
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Sohrabi Y, Sonntag GVH, Braun LC, Lagache SMM, Liebmann M, Klotz L, Godfrey R, Kahles F, Waltenberger J, Findeisen HM. LXR Activation Induces a Proinflammatory Trained Innate Immunity-Phenotype in Human Monocytes. Front Immunol 2020; 11:353. [PMID: 32210962 PMCID: PMC7077358 DOI: 10.3389/fimmu.2020.00353] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 02/13/2020] [Indexed: 12/28/2022] Open
Abstract
Objectives The concept of trained innate immunity describes a long-term proinflammatory memory in innate immune cells. Trained innate immunity is regulated through reprogramming of cellular metabolic pathways including cholesterol and fatty acid synthesis. Here, we have analyzed the role of Liver X Receptor (LXR), a key regulator of cholesterol and fatty acid homeostasis, in trained innate immunity. Methods and Results Human monocytes were isolated and incubated with different stimuli for 24 h, including LXR agonists, antagonists and Bacillus Calmette-Guerin (BCG) vaccine. After 5 days resting time, cells were restimulated with the TLR2-agonist Pam3cys. LXR activation did not only increase BCG trained immunity, but also induced a long-term inflammatory activation by itself. This inflammatory activation by LXR agonists was accompanied by characteristic features of trained innate immunity, such as activating histone marks on inflammatory gene promoters and metabolic reprogramming with increased lactate production and decreased oxygen consumption rate. Mechanistically, LXR priming increased cellular acetyl-CoA levels and was dependent on the activation of the mevalonate pathway and IL-1β signaling. In contrast to mevalonate pathway inhibition, blocking fatty acid synthesis further increased proinflammatory priming by LXR. Conclusion We demonstrate that LXR activation induces a proinflammatory trained immunity phenotype in human monocytes through epigenetic and metabolic reprogramming. Our data reveal important novel aspects of LXR signaling in innate immunity.
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Affiliation(s)
- Yahya Sohrabi
- Department of Cardiology I - Coronary and Peripheral Vascular Disease, Heart Failure, University Hospital Münster, Münster, Germany
| | - Glenn V H Sonntag
- Department of Cardiology I - Coronary and Peripheral Vascular Disease, Heart Failure, University Hospital Münster, Münster, Germany
| | - Laura C Braun
- Department of Cardiology I - Coronary and Peripheral Vascular Disease, Heart Failure, University Hospital Münster, Münster, Germany
| | - Sina M M Lagache
- Department of Cardiology I - Coronary and Peripheral Vascular Disease, Heart Failure, University Hospital Münster, Münster, Germany
| | - Marie Liebmann
- Clinic of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, Germany
| | - Luisa Klotz
- Clinic of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, Germany
| | - Rinesh Godfrey
- Department of Cardiology I - Coronary and Peripheral Vascular Disease, Heart Failure, University Hospital Münster, Münster, Germany
| | - Florian Kahles
- Department of Internal Medicine I-Cardiology, University Hospital Aachen, Aachen, Germany
| | - Johannes Waltenberger
- Department of Cardiology and Angiology, University Hospital Münster, Münster, Germany.,Cells-in-Motion Cluster of Excellence (EXC 1003 - CiM), University of Münster, Münster, Germany
| | - Hannes M Findeisen
- Department of Cardiology I - Coronary and Peripheral Vascular Disease, Heart Failure, University Hospital Münster, Münster, Germany
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17
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Vivas W, Leonhardt I, Hünniger K, Häder A, Marolda A, Kurzai O. Multiple Signaling Pathways Involved in Human Dendritic Cell Maturation Are Affected by the Fungal Quorum-Sensing Molecule Farnesol. THE JOURNAL OF IMMUNOLOGY 2019; 203:2959-2969. [DOI: 10.4049/jimmunol.1900431] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 09/25/2019] [Indexed: 01/30/2023]
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18
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Tel-Karthaus N, Kers-Rebel ED, Looman MW, Ichinose H, de Vries CJ, Ansems M. Nuclear Receptor Nur77 Deficiency Alters Dendritic Cell Function. Front Immunol 2018; 9:1797. [PMID: 30123220 PMCID: PMC6085422 DOI: 10.3389/fimmu.2018.01797] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 07/20/2018] [Indexed: 12/18/2022] Open
Abstract
Dendritic cells (DCs) are the professional antigen-presenting cells of the immune system. Proper function of DCs is crucial to elicit an effective immune response against pathogens and to induce antitumor immunity. Different members of the nuclear receptor (NR) family of transcription factors have been reported to affect proper function of immune cells. Nur77 is a member of the NR4A subfamily of orphan NRs that is expressed and has a function within the immune system. We now show that Nur77 is expressed in different murine DCs subsets in vitro and ex vivo, in human monocyte-derived DCs (moDCs) and in freshly isolated human BDCA1+ DCs, but its expression is dispensable for DC development in the spleen and lymph nodes. We show, by siRNA-mediated knockdown of Nur77 in human moDCs and by using Nur77-/- murine DCs, that Nur77-deficient DCs have enhanced inflammatory responses leading to increased T cell proliferation. Treatment of human moDCs with 6-mercaptopurine, an activator of Nur77, leads to diminished DC activation resulting in an impaired capacity to induce IFNγ production by allogeneic T cells. Altogether, our data show a yet unexplored role for Nur77 in modifying the activation status of murine and human DCs. Ultimately, targeting Nur77 may prove to be efficacious in boosting or diminishing the activation status of DCs and may lead to the development of improved DC-based immunotherapies in, respectively, cancer treatment or treatment of autoimmune diseases.
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Affiliation(s)
- Nina Tel-Karthaus
- Department of Radiation Oncology, Radiotherapy & OncoImmunology Laboratory, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Esther D Kers-Rebel
- Department of Radiation Oncology, Radiotherapy & OncoImmunology Laboratory, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Maaike W Looman
- Department of Radiation Oncology, Radiotherapy & OncoImmunology Laboratory, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Hiroshi Ichinose
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Carlie J de Vries
- Department of Medical Biochemistry, Academic Medical Center, Amsterdam Cardiovascular Sciences, Amsterdam, Netherlands
| | - Marleen Ansems
- Department of Radiation Oncology, Radiotherapy & OncoImmunology Laboratory, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
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19
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Raaijmakers TK, Ansems M. Microenvironmental derived factors modulating dendritic cell function and vaccine efficacy: the effect of prostanoid receptor and nuclear receptor ligands. Cancer Immunol Immunother 2018; 67:1789-1796. [PMID: 29998375 PMCID: PMC6208817 DOI: 10.1007/s00262-018-2205-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 07/09/2018] [Indexed: 01/20/2023]
Abstract
Dendritic cells (DCs) are widely used in DC-based immunotherapies because of their capacity to steer immune responses. So far treatment success is limited and more functional knowledge on how DCs initiate and stably drive specific responses is needed. Many intrinsic and extrinsic factors contribute to how DCs skew the immune response towards immunity or tolerance. The origin and type of DC, its maturation status, but also factors they encounter in the in vitro or in vivo microenvironment they reside in during differentiation and maturation affect this balance. Treatment success of DC vaccines will, therefore, also depend on the presence of these factors during the process of vaccination. Identification and further knowledge of natural and pharmacological compounds that modulate DC differentiation and function towards a specific response may help to improve current DC-based immunotherapies. This review focuses on factors that could improve the efficacy of DC vaccines in (pre-)clinical studies to enhance DC-based immunotherapy, with a particular emphasis on compounds acting on prostanoid or nuclear receptor families.
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Affiliation(s)
- Tonke K Raaijmakers
- Radiotherapy and OncoImmunology Laboratory, Department of Radiation Oncology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein Zuid 32, 6525 GA, Nijmegen, The Netherlands
- Department of Anesthesiology, Pain and Palliative Medicine, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA, Nijmegen, The Netherlands
| | - Marleen Ansems
- Radiotherapy and OncoImmunology Laboratory, Department of Radiation Oncology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein Zuid 32, 6525 GA, Nijmegen, The Netherlands.
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20
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Liver X Receptor Nuclear Receptors Are Transcriptional Regulators of Dendritic Cell Chemotaxis. Mol Cell Biol 2018; 38:MCB.00534-17. [PMID: 29507185 DOI: 10.1128/mcb.00534-17] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 02/10/2018] [Indexed: 12/20/2022] Open
Abstract
The liver X receptors (LXRs) are ligand-activated nuclear receptors with established roles in the maintenance of lipid homeostasis in multiple tissues. LXRs exert additional biological functions as negative regulators of inflammation, particularly in macrophages. However, the transcriptional responses controlled by LXRs in other myeloid cells, such as dendritic cells (DCs), are still poorly understood. Here we used gain- and loss-of-function models to characterize the impact of LXR deficiency on DC activation programs. Our results identified an LXR-dependent pathway that is important for DC chemotaxis. LXR-deficient mature DCs are defective in stimulus-induced migration in vitro and in vivo Mechanistically, we show that LXRs facilitate DC chemotactic signaling by regulating the expression of CD38, an ectoenzyme important for leukocyte trafficking. Pharmacological or genetic inactivation of CD38 activity abolished the LXR-dependent induction of DC chemotaxis. Using the low-density lipoprotein receptor-deficient (LDLR-/-) LDLR-/- mouse model of atherosclerosis, we also demonstrated that hematopoietic CD38 expression is important for the accumulation of lipid-laden myeloid cells in lesions, suggesting that CD38 is a key factor in leukocyte migration during atherogenesis. Collectively, our results demonstrate that LXRs are required for the efficient emigration of DCs in response to chemotactic signals during inflammation.
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21
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Weng Y, Mizuno N, Dong J, Segawa R, Yonezawa T, Cha BY, Woo JT, Moriya T, Hiratsuka M, Hirasawa N. Induction of thymic stromal lymphopoietin by a steroid alkaloid derivative in mouse keratinocytes. Int Immunopharmacol 2017; 55:28-37. [PMID: 29220720 DOI: 10.1016/j.intimp.2017.11.045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Revised: 11/15/2017] [Accepted: 11/30/2017] [Indexed: 01/16/2023]
Abstract
Thymic stromal lymphopoietin (TSLP) plays critical roles in inducing and exacerbating allergic diseases. Chemical compounds that induce TSLP production can enhance sensitization to antigens and exacerbate allergic inflammation. Hence, identifying such chemicals will be important to prevent an increase in allergic diseases. In the present study, we found, for the first time, that a steroid alkaloid derivative, code no. 02F04, concentration and time dependently induced mRNA expression and production of TSLP in a mouse keratinocyte cell line, PAM212. In particular, the activity of 02F04 was selective to TSLP. As an analogue of the liver X receptor (LXR) endogenous ligand, 02F04 rapidly increased ATP-binding cassette transporter A1 (ABCA1) expression by regulating the nuclear receptor of LXR. However, instead of being inhibited by the LXR antagonist, 02F04-induced TSLP production was delayed and markedly suppressed by inhibitors of phospholipase C (PLC), pan-protein kinase C (PKC), PKCδ, Rho-associated protein kinase (ROCK), extracellular signal-regulated kinase (ERK) 1/2, and IκΒ kinase 2 (IKK2). Treatment with 02F04 caused the formation of F-actin filaments surrounding the nucleus of PAM212 cells, which then disappeared following addition of ROCK inhibitor. 02F04 also induced phosphorylation of ERK1/2 from 2h after treatment, with a maximum at 24h, and increased nuclear factor-κB (NF-κB) promoter activity by 1.3-fold. Taken together, these results indicate that 02F04-induced TSLP production is regulated via distinct signal transduction pathways, including PLC, PKC, ROCK, ERK1/2, and NF-κB but not nuclear receptors. 02F04, with a unique skeletal structure in inducing TSLP production, can represent a potential new tool for investigating the role of TSLP in allergic diseases.
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Affiliation(s)
- Yan Weng
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Miyagi, Japan; Department of Pharmacy, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, Shaanxi, PR China
| | - Natsumi Mizuno
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Miyagi, Japan
| | - Jiangxu Dong
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Miyagi, Japan
| | - Ryosuke Segawa
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Miyagi, Japan
| | - Takayuki Yonezawa
- Research Institute for Biological Functions, Chubu University, Kasugai 487-8501, Aichi, Japan
| | - Byung Yoon Cha
- Research Institute for Biological Functions, Chubu University, Kasugai 487-8501, Aichi, Japan
| | - Je-Tae Woo
- Department of Biological Chemistry, College of Bioscience and Biotechnology, Chubu University, Kasugai 487-8501, Aichi, Japan
| | - Takahiro Moriya
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Miyagi, Japan
| | - Masahiro Hiratsuka
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Miyagi, Japan
| | - Noriyasu Hirasawa
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Miyagi, Japan.
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22
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Robinson GA, Waddington KE, Pineda-Torra I, Jury EC. Transcriptional Regulation of T-Cell Lipid Metabolism: Implications for Plasma Membrane Lipid Rafts and T-Cell Function. Front Immunol 2017; 8:1636. [PMID: 29225604 PMCID: PMC5705553 DOI: 10.3389/fimmu.2017.01636] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 11/09/2017] [Indexed: 01/10/2023] Open
Abstract
It is well established that cholesterol and glycosphingolipids are enriched in the plasma membrane (PM) and form signaling platforms called lipid rafts, essential for T-cell activation and function. Moreover, changes in PM lipid composition affect the biophysical properties of lipid rafts and have a role in defining functional T-cell phenotypes. Here, we review the role of transcriptional regulators of lipid metabolism including liver X receptors α/β, peroxisome proliferator-activated receptor γ, estrogen receptors α/β (ERα/β), and sterol regulatory element-binding proteins in T-cells. These receptors lie at the interface between lipid metabolism and immune cell function and are endogenously activated by lipids and/or hormones. Importantly, they regulate cellular cholesterol, fatty acid, glycosphingolipid, and phospholipid levels but are also known to modulate a broad spectrum of immune responses. The current evidence supporting a role for lipid metabolism pathways in controlling immune cell activation by influencing PM lipid raft composition in health and disease, and the potential for targeting lipid biosynthesis pathways to control unwanted T-cell activation in autoimmunity is reviewed.
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Affiliation(s)
- George A. Robinson
- Centre of Rheumatology, Division of Medicine, University College London, London, United Kingdom
| | - Kirsty E. Waddington
- Centre of Rheumatology, Division of Medicine, University College London, London, United Kingdom
- Clinical Pharmacology, Division of Medicine, University College London, London, United Kingdom
| | - Ines Pineda-Torra
- Clinical Pharmacology, Division of Medicine, University College London, London, United Kingdom
| | - Elizabeth C. Jury
- Centre of Rheumatology, Division of Medicine, University College London, London, United Kingdom
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23
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Wang Y, Zhang X, Wei Z, Wang J, Zhang Y, Shi M, Yang Z, Fu Y. Platycodin D suppressed LPS-induced inflammatory response by activating LXRα in LPS-stimulated primary bovine mammary epithelial cells. Eur J Pharmacol 2017; 814:138-143. [DOI: 10.1016/j.ejphar.2017.07.037] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 07/19/2017] [Accepted: 07/20/2017] [Indexed: 11/25/2022]
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24
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Cholesterol Accumulation in CD11c + Immune Cells Is a Causal and Targetable Factor in Autoimmune Disease. Immunity 2017; 45:1311-1326. [PMID: 28002731 DOI: 10.1016/j.immuni.2016.11.008] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 07/25/2016] [Accepted: 10/20/2016] [Indexed: 02/06/2023]
Abstract
Liver X receptors (LXRs) are regulators of cholesterol metabolism that also modulate immune responses. Inactivation of LXR α and β in mice leads to autoimmunity; however, how the regulation of cholesterol metabolism contributes to autoimmunity is unclear. Here we found that cholesterol loading of CD11c+ cells triggered the development of autoimmunity, whereas preventing excess lipid accumulation by promoting cholesterol efflux was therapeutic. LXRβ-deficient mice crossed to the hyperlipidemic ApoE-deficient background or challenged with a high-cholesterol diet developed autoantibodies. Cholesterol accumulation in lymphoid organs promoted T cell priming and stimulated the production of the B cell growth factors Baff and April. Conversely, B cell expansion and the development of autoantibodies in ApoE/LXR-β-deficient mice was reversed by ApoA-I expression. These findings implicate cholesterol imbalance as a contributor to immune dysfunction and suggest that stimulating HDL-dependent reverse cholesterol transport could be beneficial in the setting of autoimmune disease.
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25
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Fessler MB. The challenges and promise of targeting the Liver X Receptors for treatment of inflammatory disease. Pharmacol Ther 2017; 181:1-12. [PMID: 28720427 DOI: 10.1016/j.pharmthera.2017.07.010] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The Liver X Receptors (LXRs) are oxysterol-activated transcription factors that upregulate a suite of genes that together promote coordinated mobilization of excess cholesterol from cells and from the body. The LXRs, like other nuclear receptors, are anti-inflammatory, inhibiting signal-dependent induction of pro-inflammatory genes by nuclear factor-κB, activating protein-1, and other transcription factors. Synthetic LXR agonists have been shown to ameliorate atherosclerosis and a wide range of inflammatory disorders in preclinical animal models. Although this has suggested potential for application to human disease, systemic LXR activation is complicated by hepatic steatosis and hypertriglyceridemia, consequences of lipogenic gene induction in the liver by LXRα. The past several years have seen the development of multiple advanced LXR therapeutics aiming to avoid hepatic lipogenesis, including LXRβ-selective agonists, tissue-selective agonists, and transrepression-selective agonists. Although several synthetic LXR agonists have made it to phase I clinical trials, none have progressed due to unforeseen adverse reactions or undisclosed reasons. Nonetheless, several sophisticated pharmacologic strategies, including structure-guided drug design, cell-specific drug targeting, as well as non-systemic drug routes have been initiated and remain to be comprehensively explored. In addition, recent studies have identified potential utility for targeting the LXRs during therapy with other agents, such as glucocorticoids and rexinoids. Despite the pitfalls encountered to date in translation of LXR agonists to human disease, it appears likely that this accelerating field will ultimately yield effective and safe applications for LXR targeting in humans.
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Affiliation(s)
- Michael B Fessler
- National Institute of Environmental Health Sciences, 111 T.W. Alexander Drive, P.O. Box 12233, MD D2-01, Research Triangle Park, NC 27709, United States.
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Cao X, Zhang L, Chen C, Wang Q, Guo L, Ma Q, Deng P, Zhu G, Li B, Pi Y, Long C, Zhang L, Yu Z, Zhou Z, Li J. The critical role of ABCG1 and PPARγ/LXRα signaling in TLR4 mediates inflammatory responses and lipid accumulation in vascular smooth muscle cells. Cell Tissue Res 2016; 368:145-157. [DOI: 10.1007/s00441-016-2518-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 09/27/2016] [Indexed: 12/15/2022]
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Saini A, Mahajan S, Gupta P. Nuclear receptor expression atlas in BMDCs: Nr4a2 restricts immunogenicity of BMDCs and impedes EAE. Eur J Immunol 2016; 46:1842-53. [PMID: 27184189 DOI: 10.1002/eji.201546229] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 04/19/2016] [Accepted: 05/12/2016] [Indexed: 01/25/2023]
Abstract
The nuclear receptor (NR) superfamily of transcription factors regulates various key aspects of physiological processes; however, their role(s) in immune cells' function are just beginning to unravel. Although few NRs have been shown to be critical for dendritic cell (DC) function, a lack of knowledge about their complete representation in DCs has limited the ability to harness their full potential. Here, we performed a comprehensive NR expression profiling and identified the key members of NR superfamily being expressed in immature, immunogenic, and tolerogenic DCs. Comparative analysis revealed discrete changes in the expression of various NRs among the studied DC subtypes, indicating a likely role in the modulation of DC functionality. Next, we characterized Nr4a2, a member of orphan NR family, and found that it suppresses the activation of bone marrow derived dendritic cells triggered by LPS. Overexpression and knockdown of Nr4a2 demonstrated that Nr4a2 orchestrates the expression of immunoregulatory genes, hence inducing a tolerogenic phenotype in bone marrow derived dendritic cells. Furthermore, we also found that Nr4a2 provides protection from EAE by promoting an increase in Treg cells, while limiting effector T cells. Our findings suggest a previously unidentified role for Nr4a2 as a regulator of DC tolerogenicity and demonstrate its potential as therapeutic target in DC-associated pathophysiologies.
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Affiliation(s)
- Ankita Saini
- Institute of Microbial Technology, Council of Scientific and Industrial Research, Chandigarh, 160036, India
| | - Sahil Mahajan
- Institute of Microbial Technology, Council of Scientific and Industrial Research, Chandigarh, 160036, India.,Department of Orthopedics, Washington University School of Medicine, St. Louis, MO, USA
| | - Pawan Gupta
- Institute of Microbial Technology, Council of Scientific and Industrial Research, Chandigarh, 160036, India
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Ballestri S, Nascimbeni F, Romagnoli D, Baldelli E, Lonardo A. The Role of Nuclear Receptors in the Pathophysiology, Natural Course, and Drug Treatment of NAFLD in Humans. Adv Ther 2016; 33:291-319. [PMID: 26921205 DOI: 10.1007/s12325-016-0306-9] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Indexed: 02/06/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) describes steatosis, nonalcoholic steatohepatitis with or without fibrosis, and hepatocellular carcinoma, namely the entire alcohol-like spectrum of liver disease though observed in the nonalcoholic, dysmetabolic, individual free of competing causes of liver disease. NAFLD, which is a major public health issue, exhibits intrahepatic triglyceride storage giving rise to lipotoxicity. Nuclear receptors (NRs) are transcriptional factors which, activated by ligands, are master regulators of metabolism and also have intricate connections with circadian control accounting for cyclical patterns in the metabolic fate of nutrients. Several transcription factors, such as peroxisome proliferator-activated receptors, liver X receptors, farnesoid X receptors, and their molecular cascades, finely regulate energetic fluxes and metabolic pathways. Dysregulation of such pathways is heavily implicated in those metabolic derangements characterizing insulin resistance and metabolic syndrome and in the histogenesis of progressive NAFLD forms. We review the role of selected NRs in NAFLD pathogenesis. Secondly, we analyze the role of NRs in the natural history of human NAFLD. Next, we discuss the results observed in humans following administration of drug agonists or antagonists of the NRs pathogenically involved in NAFLD. Finally, general principles of treatment and lines of research in human NAFLD are briefly examined.
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Affiliation(s)
| | - Fabio Nascimbeni
- NOCSAE, Outpatient Liver Clinic and Operating Unit Internal Medicine, Azienda USL Modena, Modena, Italy
- University of Modena and Reggio Emilia, Modena, Italy
| | - Dante Romagnoli
- NOCSAE, Outpatient Liver Clinic and Operating Unit Internal Medicine, Azienda USL Modena, Modena, Italy
| | | | - Amedeo Lonardo
- NOCSAE, Outpatient Liver Clinic and Operating Unit Internal Medicine, Azienda USL Modena, Modena, Italy.
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Regulation of Adaptive Immunity in Health and Disease by Cholesterol Metabolism. Curr Allergy Asthma Rep 2015; 15:48. [PMID: 26149587 DOI: 10.1007/s11882-015-0548-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Four decades ago, it was observed that stimulation of T cells induces rapid changes in cellular cholesterol that are required before proliferation can commence. Investigators returning to this phenomenon have finally revealed its molecular underpinnings. Cholesterol trafficking and its dysregulation are now also recognized to strongly influence dendritic cell function, T cell polarization, and antibody responses. In this review, the state of the literature is reviewed on how cholesterol and its trafficking regulate the cells of the adaptive immune response and in vivo disease phenotypes of dysregulated adaptive immunity, including allergy, asthma, and autoimmune disease. Emerging evidence supporting a potential role for statins and other lipid-targeted therapies in the treatment of these diseases is presented. Just as vascular biologists have embraced immunity in the pathogenesis and treatment of atherosclerosis, so should basic and clinical immunologists in allergy, pulmonology, and other disciplines seek to encompass a basic understanding of lipid science.
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Abstract
The liver X receptors (LXRs), LXRα and LXRβ, are transcription factors with well-established roles in the regulation of lipid metabolism and cholesterol homeostasis. In addition, LXRs influence innate and adaptive immunity, including responses to inflammatory stimuli, proliferation and differentiation, migration, apoptosis and survival. However, the majority of work describing the role of LXRs in immune cells has been carried out in mouse models, and there are a number of known species-specific differences concerning LXR function. Here we review what is known about the role of LXRs in human immune cells, demonstrating the importance of these receptors in the integration of lipid metabolism and immune function, but also highlighting the need for a better understanding of the species, isoform, and cell-type specific effects of LXR activation.
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Molecular Interactions between NR4A Orphan Nuclear Receptors and NF-κB Are Required for Appropriate Inflammatory Responses and Immune Cell Homeostasis. Biomolecules 2015; 5:1302-18. [PMID: 26131976 PMCID: PMC4598753 DOI: 10.3390/biom5031302] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 06/16/2015] [Accepted: 06/16/2015] [Indexed: 12/22/2022] Open
Abstract
Appropriate innate and adaptive immune responses are essential for protection and resolution against chemical, physical or biological insults. Immune cell polarization is fundamental in orchestrating distinct phases of inflammation, specifically acute phase responses followed by resolution and tissue repair. Dysregulation of immune cell and inflammatory responses is a hallmark of multiple diseases encompassing atherosclerosis, rheumatoid arthritis, psoriasis and metabolic syndromes. A master transcriptional mediator of diverse inflammatory signaling and immune cell function is NF-κB, and altered control of this key regulator can lead to an effective switch from acute to chronic inflammatory responses. Members of the nuclear receptor (NR) superfamily of ligand-dependent transcription factors crosstalk with NF-κB to regulate immune cell function(s). Within the NR superfamily the NR4A1-3 orphan receptors have emerged as important regulators of immune cell polarization and NF-κB signaling. NR4A receptors modulate NF-κB activity in a dynamic fashion, either repressing or enhancing target gene expression leading to altered inflammatory outcome. Here we will discuss the pivotal role NR4A’s receptors play in orchestrating immune cell homeostasis through molecular crosstalk with NF-κB. Specifically, we will examine such NR4A/NF-κB interactions within the context of distinct cell phenotypes, including monocyte, macrophage, T cells, endothelial, and mesenchymal cells, which play a role in inflammation-associated disease. Finally, we review the therapeutic potential of altering NR4A/NF-κB interactions to limit hyper-inflammatory responses in vivo.
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Salvatore G, Bernoud-Hubac N, Bissay N, Debard C, Daira P, Meugnier E, Proamer F, Hanau D, Vidal H, Aricò M, Delprat C, Mahtouk K. Human monocyte-derived dendritic cells turn into foamy dendritic cells with IL-17A. J Lipid Res 2015; 56:1110-22. [PMID: 25833686 DOI: 10.1194/jlr.m054874] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Indexed: 02/07/2023] Open
Abstract
Interleukin 17A (IL-17A) is a proinflammatory cytokine involved in the pathogenesis of chronic inflammatory diseases. In the field of immunometabolism, we have studied the impact of IL-17A on the lipid metabolism of human in vitro-generated monocyte-derived dendritic cells (DCs). Microarrays and lipidomic analysis revealed an intense remodeling of lipid metabolism induced by IL-17A in DCs. IL-17A increased 2-12 times the amounts of phospholipids, cholesterol, triglycerides, and cholesteryl esters in DCs. Palmitic (16:0), stearic (18:0), and oleic (18:ln-9c) acid were the main fatty acid chains present in DCs. They were strongly increased in response to IL-17A while their relative proportion remained unchanged. Capture of extracellular lipids was the major mechanism of lipid droplet accumulation, visualized by electron microscopy and Oil Red O staining. Besides this foamy phenotype, IL-17A induced a mixed macrophage-DC phenotype and expression of the nuclear receptor NR1H3/liver X receptor-α, previously identified in the context of atherosclerosis as the master regulator of cholesterol homeostasis in macrophages. These IL-17A-treated DCs were as competent as untreated DCs to stimulate allogeneic naive T-cell proliferation. Following this first characterization of lipid-rich DCs, we propose to call these IL-17A-dependent cells "foamy DCs" and discuss the possible existence of foamy DCs in atherosclerosis, a metabolic and inflammatory disorder involving IL-17A.
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Affiliation(s)
- Giulia Salvatore
- CNRS, UMR5239, Laboratoire de Biologie Moléculaire de la Cellule, 69007 Lyon, France Ecole Normale Supérieure de Lyon, 69007 Lyon, France Université de Lyon, 69003 Lyon, France Université de Lyon 1, 69622 Villeurbanne, France Université de Florence, 50134 Florence, Italy
| | - Nathalie Bernoud-Hubac
- INSERM, U 1060 (CarMeN), INRA U1235, Institut Multidisciplinaire de Biochimie des Lipides, Institut National des Sciences Appliqués, 69621 Villeurbanne, France
| | - Nathalie Bissay
- CNRS, UMR5239, Laboratoire de Biologie Moléculaire de la Cellule, 69007 Lyon, France Ecole Normale Supérieure de Lyon, 69007 Lyon, France Université de Lyon, 69003 Lyon, France Université de Lyon 1, 69622 Villeurbanne, France
| | - Cyrille Debard
- INSERM, U 1060 (CarMeN), INRA U1235, Institut Multidisciplinaire de Biochimie des Lipides, Institut National des Sciences Appliqués, 69621 Villeurbanne, France
| | - Patricia Daira
- Functional Lipidomics Platform, Institut Multidisciplinaire de Biochimie des Lipides/Carnot Lisa, INSA-Lyon, 69622 Villeurbanne, France
| | - Emmanuelle Meugnier
- INSERM, U 1060 (CarMeN), INRA U1235, Institut Multidisciplinaire de Biochimie des Lipides, Institut National des Sciences Appliqués, 69621 Villeurbanne, France
| | - Fabienne Proamer
- Unité Mixte de Recherche Santé UMR S949, Institut National de la Santé et de la Recherche Médicale, 67000 Strasbourg, France Université de Strasbourg, 67400 Strasbourg, France Histocompatibility Laboratory, Etablissement Français du Sang-Alsace, 67000 Strasbourg, France
| | - Daniel Hanau
- Unité Mixte de Recherche Santé UMR S949, Institut National de la Santé et de la Recherche Médicale, 67000 Strasbourg, France Université de Strasbourg, 67400 Strasbourg, France Histocompatibility Laboratory, Etablissement Français du Sang-Alsace, 67000 Strasbourg, France
| | - Hubert Vidal
- INSERM, U 1060 (CarMeN), INRA U1235, Institut Multidisciplinaire de Biochimie des Lipides, Institut National des Sciences Appliqués, 69621 Villeurbanne, France
| | - Maurizio Aricò
- Istituto Toscano Tumori (I.T.T), 50139 Florence, Italy Azienda Sanitaria Provinciale 7, 97100 Ragusa, Italy
| | - Christine Delprat
- CNRS, UMR5239, Laboratoire de Biologie Moléculaire de la Cellule, 69007 Lyon, France Ecole Normale Supérieure de Lyon, 69007 Lyon, France Université de Lyon, 69003 Lyon, France Université de Lyon 1, 69622 Villeurbanne, France Institut Universitaire de France, 75005 Paris, France
| | - Karène Mahtouk
- CNRS, UMR5239, Laboratoire de Biologie Moléculaire de la Cellule, 69007 Lyon, France Ecole Normale Supérieure de Lyon, 69007 Lyon, France Université de Lyon, 69003 Lyon, France Université de Lyon 1, 69622 Villeurbanne, France
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Jakobsson T, Vedin LL, Hassan T, Venteclef N, Greco D, D'Amato M, Treuter E, Gustafsson JÅ, Steffensen KR. The oxysterol receptor LXRβ protects against DSS- and TNBS-induced colitis in mice. Mucosal Immunol 2014; 7:1416-28. [PMID: 24803164 DOI: 10.1038/mi.2014.31] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 04/01/2014] [Indexed: 02/04/2023]
Abstract
We examined the function of the oxysterol receptors (LXRs) in inflammatory bowel disease (IBD) through studying dextran sodium sulfate (DSS)- and 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice and by elucidating molecular mechanisms underlying their anti-inflammatory action. We observed that Lxr-deficient mice are more susceptible to colitis. Clinical indicators of colitis including weight loss, diarrhea and blood in feces appeared earlier and were more severe in Lxr-deficient mice and particularly LXRβ protected against symptoms of colitis. Addition of an LXR agonist led to faster recovery and increased survival. In contrast, Lxr-deficient mice showed slower recovery and decreased survival. In Lxr-deficient mice, inflammatory cytokines and chemokines were increased together with increased infiltration of immune cells in the colon epithelium. Activation of LXRs strongly suppressed expression of inflammatory mediators including TNFα. While LXRα had anti-inflammatory effects in CD11b(+) immune cell populations, LXRβ in addition had anti-inflammatory effects in colon epithelial cells. Lack of LXRβ also induced CD4(+)/CD3(+) immune cell recruitment to the inflamed colon. Expression of both LXRA and LXRB was significantly suppressed in inflamed colon from subjects with IBD compared with non-inflamed colon. Taken together, our observations suggest that the LXRs could provide interesting targets to reduce the inflammatory responses in IBD.
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Affiliation(s)
- T Jakobsson
- Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden
| | - L-L Vedin
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - T Hassan
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - N Venteclef
- Institute of Cardiometabolism and Nutrition, INSERM, Université Pierre et Marie Curie-Paris 6, Cordeliers Research Center, Paris, France
| | - D Greco
- Finnish Institute of Occupational Health, Helsinki, Finland
| | - M D'Amato
- Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden
| | - E Treuter
- Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden
| | - J-Å Gustafsson
- 1] Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden [2] Center for Nuclear Receptors and Cell Signaling, Department of Biology and Biochemistry, University of Houston, Houston, Texas, USA
| | - K R Steffensen
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
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Ma X, Wang Q, Liu Y, Chen Y, Zhang L, Jiang M, Li X, Xiang R, Miao RQ, Duan Y, Han J. Inhibition of tumor growth by U0126 is associated with induction of interferon-γ production. Int J Cancer 2014; 136:771-83. [PMID: 24947959 DOI: 10.1002/ijc.29038] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 05/13/2014] [Accepted: 06/04/2014] [Indexed: 12/25/2022]
Abstract
Several MEK1/2 inhibitors have been in clinical trial evaluation for cancer treatment. Interferon-γ (IFN-γ) is a cytokine with multiple biological functions including antitumor activity. Expression of IFN-γ can be induced by liver X receptor (LXR), a ligand-activated transcription factor. However, it remains unknown if the anti-cancer action of MEK1/2 inhibitors is completed, at least in part, by activating IFN-γ expression. In this study, we determined that U0126, a MEK1/2 inhibitor, increased tumor-free and survival rates and decreased growth of inoculated Lewis lung carcinomas in wild type mice. However, the protective effects were substantially attenuated in IFN-γ deficient (IFN-γ-/-) mice. At cellular and molecular levels, MEK1/2 inhibitors increased IFN-γ protein and mRNA expression and activated natural IFN-γ promoter but not the IFN-γ promoters with mutations of the LXR responsive elements (LXREs). MEK1/2 inhibitors also enhanced formation of the LXRE-nuclear protein complexes by inducing LXR expression and nuclear translocation. Similarly, MEK1/2 siRNA inhibited phosphorylation of ERK1/2 by MEK1/2 while activated IFN-γ expression. In contrast, inhibition of LXR expression by siRNA blocked MEK1/2 inhibitors-induced IFN-γ expression. U0126 also inhibited chemicals-induced pulmonary carcinomas, which was associated with increased IFN-γ expression in the lung. Taken together, our study suggests that MEK1/2 inhibitors induce IFN-γ production in an LXR-dependent manner and the induction of IFN-γ expression can partially contribute to the anti-tumorigenic properties of U0126.
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Affiliation(s)
- Xingzhe Ma
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China; College of Life Sciences, Nankai University, Tianjin, China
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Han M, Liang L, Liu LR, Yue J, Zhao YL, Xiao HP. Liver X receptor gene polymorphisms in tuberculosis: effect on susceptibility. PLoS One 2014; 9:e95954. [PMID: 24788534 PMCID: PMC4006844 DOI: 10.1371/journal.pone.0095954] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 04/02/2014] [Indexed: 01/06/2023] Open
Abstract
Objectives The Liver X receptors (LXRs), Liver X receptor A (LXRA) and Liver X receptor B (LXRB), regulate lipid metabolism and antimicrobial response. LXRs have a crucial role in the control of Mycobacterium tuberculosis (M.tb). Lacking LXRs mice is more susceptibility to infection M.tb, developing higher bacterial burdens and an increase in the size and number of granulomatous lesions. We aimed to assess the associations between single nucleotide polymorphisms (SNPs) in LXRs and risk of tuberculosis. Methods We sequenced the LXRs genes to detect SNPs and to examine genotypic frequencies in 600 patients and 620 healthy controls to investigate for associations with tuberculosis (TB) in the Chinese Han population. DNA re-sequencing revealed eight common variants in the LXRs genes. Results The G allele of rs1449627 and the T allele of rs1405655 demonstrated an increased risk of developing TB (p<0.001, p = 0.002), and the T allele of rs3758673, the T allele of rs2279238, and the C allele of rs1449626 in LXRA and the C allele of rs17373080, the G allele of rs2248949, and the C allele of rs1052677 in LXRB were protective against TB patients compared to healthy controls (p = 0.0002, p = 0.006, p<0.001, p = 0.004, p = 0.008, p = 0.003, respectively). All SNP genotypes were significantly associated with TB. An estimation of the frequencies of haplotypes revealed two potential risk haplotypes,GGCG in LXRB (p = 0.004,) and TTCG in LXRA (p<0.001, p = 0.004). Moreover, three protective haplotypes, TTAT and CCAT in LXRA and CATC in LXRB, were significantly “protective” (p = 0.008, p<0.001, p = 0.031) for TB. Furthermore, we determined that the LXRs SNPs were nominally associated with the clinical pattern of disease. Conclusions Our study data supported that LXRs play a fundamental role in the genetic susceptibility to TB and to different clinical patterns of disease. Thus, further investigation is required in larger populations and in additional areas.
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Affiliation(s)
- Min Han
- Shanghai Key Laboratory of Mycobacterium Tuberculosis, Shanghai Pulmonary Hospital Affiliated to Tongji University School of Medicine, Shanghai, P.R. China
| | - Li Liang
- Shanghai Key Laboratory of Mycobacterium Tuberculosis, Shanghai Pulmonary Hospital Affiliated to Tongji University School of Medicine, Shanghai, P.R. China
| | - Li-rong Liu
- Shanghai Key Laboratory of Mycobacterium Tuberculosis, Shanghai Pulmonary Hospital Affiliated to Tongji University School of Medicine, Shanghai, P.R. China
| | - Jun Yue
- Shanghai Key Laboratory of Mycobacterium Tuberculosis, Shanghai Pulmonary Hospital Affiliated to Tongji University School of Medicine, Shanghai, P.R. China
- * E-mail:
| | - Yan-lin Zhao
- National Center for Tuberculosis Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, P.R. China
| | - He-ping Xiao
- Shanghai Key Laboratory of Mycobacterium Tuberculosis, Shanghai Pulmonary Hospital Affiliated to Tongji University School of Medicine, Shanghai, P.R. China
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Zhong L, Yang Q, Xie W, Zhou J. Liver X receptor regulates mouse GM-CSF-derived dendritic cell differentiation in vitro. Mol Immunol 2014; 60:32-43. [PMID: 24747959 DOI: 10.1016/j.molimm.2014.03.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 02/27/2014] [Accepted: 03/18/2014] [Indexed: 12/15/2022]
Abstract
Liver X receptors (LXRs) are nuclear receptors that play an essential role in lipid and cholesterol metabolism. Emerging studies indicate a potential function for LXRs in regulating dendritic cell (DC)-dependent immune responses; however, the role of LXRs in DC differentiation is largely unknown. Here, we report that LXRα regulates the differentiation of mouse GM-CSF-derived DCs. Activation or overexpression of LXRα significantly enhanced myeloid DC differentiation from mouse bone marrow (BM) cells, while siRNA-mediated knockdown of LXRα suppressed DC differentiation. In addition, we demonstrated that LXR agonist-programmed DCs showed an increased capacity for stimulating T-cell proliferation. Mechanistic studies showed that activation of LXR could inhibit the phosphorylation of STAT3 and downregulate the expression of its target, S100A9, an important negative regulator of myeloid DC differentiation. We also found that Histone deacetylase (HDAC) inhibition interfered with the effect of LXR on STAT3 signaling via acetylation of STAT3. Chromatin immunoprecipitation assays confirmed that LXR activation and HDAC inhibition balanced the recruitment of STAT3 to the S100A9 promoter, which involved distinct post-translational modifications of STAT3. In conclusion, our observations demonstrated a novel role for LXRα in GM-CSF-derived DC differentiation and revealed the underlying mechanism.
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Affiliation(s)
- Limei Zhong
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-Sen University, 74 Zhongshan 2nd Road, Guangzhou 510080, China
| | - Quan Yang
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-Sen University, 74 Zhongshan 2nd Road, Guangzhou 510080, China
| | - Wen Xie
- Department of Pharmaceutical Sciences, Center for Pharmacogenetics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jie Zhou
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-Sen University, 74 Zhongshan 2nd Road, Guangzhou 510080, China; Key Laboratory of Tropical Disease Control, Sun Yat-sen University, Chinese Ministry of Education, Guangzhou, China.
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Kiss M, Czimmerer Z, Nagy L. The role of lipid-activated nuclear receptors in shaping macrophage and dendritic cell function: From physiology to pathology. J Allergy Clin Immunol 2013; 132:264-86. [PMID: 23905916 DOI: 10.1016/j.jaci.2013.05.044] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 05/16/2013] [Accepted: 05/30/2013] [Indexed: 02/06/2023]
Abstract
Nuclear receptors are ligand-activated transcription factors linking lipid signaling to the expression of the genome. There is increasing appreciation of the involvement of this receptor network in the metabolic programming of macrophages and dendritic cells (DCs), essential members of the innate immune system. In this review we focus on the role of retinoid X receptor, retinoic acid receptor, peroxisome proliferator-associated receptor γ, liver X receptor, and vitamin D receptor in shaping the immune and metabolic functions of macrophages and DCs. We also provide an overview of the contribution of macrophage- and DC-expressed nuclear receptors to various immunopathologic conditions, such as rheumatoid arthritis, inflammatory bowel disease, systemic lupus erythematosus, asthma, and some others. We suggest that systematic analyses of the roles of these receptors and their activating lipid ligands in immunopathologies combined with complementary and focused translational and clinical research will be crucial for the development of new therapies using the many molecules available to target nuclear receptors.
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Affiliation(s)
- Mate Kiss
- Department of Biochemistry and Molecular Biology, Research Center for Molecular Medicine, University of Debrecen, Medical and Health Science Center, Debrecen, Hungary
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Canavan M, McCarthy C, Larbi NB, Dowling JK, Collins L, O'Sullivan F, Hurley G, Murphy C, Quinlan A, Moloney G, Darby T, MacSharry J, Kagechika H, Moynagh P, Melgar S, Loscher CE. Activation of liver X receptor suppresses the production of the IL-12 family of cytokines by blocking nuclear translocation of NF-κBp50. Innate Immun 2013; 20:675-87. [PMID: 24045337 DOI: 10.1177/1753425913501915] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
There is now convincing evidence that liver X receptor (LXR) is an important modulator of the inflammatory response; however, its mechanism of action remains unclear. This study aimed to examine the effect of LXR on the IL-12 family of cytokines and examined the mechanism by which LXR exerted this effect. We first demonstrated that activation of murine-derived dendritic cells (DC) with a specific agonist to LXR enhanced expression of LXR following activation with LPS, suggesting a role in inflammation. Furthermore, we showed LXR expression to be increased in vivo in dextrane sulphate sodium-induced colitis. LXR activation also suppressed production of IL-12p40, IL-12p70, IL-27 and IL-23 in murine-derived DC following stimulation with LPS, and specifically targeted the p35, p40 and EBI3 subunits of the IL-12 cytokine family, which are under the control of the NF-κB subunit p50 (NF-κBp50). Finally, we demonstrated that LXR can associate with NF-κBp50 in DC and that LXR activation prevents translocation of the p50 subunit into the nucleus. In summary, our study indicates that LXR can specifically suppress the IL-12 family of cytokines though its association with NF-κBp50 and highlights its potential as a therapeutic target for chronic inflammatory diseases.
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Affiliation(s)
- Mary Canavan
- Immunomodulation Research Group, School of Biotechnology, Dublin City University, Dublin, Ireland
| | - Ciara McCarthy
- Immunomodulation Research Group, School of Biotechnology, Dublin City University, Dublin, Ireland
| | - Nadia Ben Larbi
- Immunomodulation Research Group, School of Biotechnology, Dublin City University, Dublin, Ireland
| | - Jennifer K Dowling
- Immunomodulation Research Group, School of Biotechnology, Dublin City University, Dublin, Ireland
| | - Laura Collins
- Immunomodulation Research Group, School of Biotechnology, Dublin City University, Dublin, Ireland
| | - Finbarr O'Sullivan
- National Institute for Cellular Biotechnology, Dublin City University, Dublin, Ireland
| | - Grainne Hurley
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - Carola Murphy
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - Aoife Quinlan
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - Gerry Moloney
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - Trevor Darby
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - John MacSharry
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - Hiroyuki Kagechika
- Institute of Biomaterials & Bioengineering, Tokyo Medical & Dental University, Tokyo, Japan
| | - Paul Moynagh
- Institute of Immunology, National University of Ireland, Maynooth, Ireland
| | - Silvia Melgar
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - Christine E Loscher
- Immunomodulation Research Group, School of Biotechnology, Dublin City University, Dublin, Ireland
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39
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Ishibashi M, Varin A, Filomenko R, Lopez T, Athias A, Gambert P, Blache D, Thomas C, Gautier T, Lagrost L, Masson D. Liver x receptor regulates arachidonic acid distribution and eicosanoid release in human macrophages: a key role for lysophosphatidylcholine acyltransferase 3. Arterioscler Thromb Vasc Biol 2013; 33:1171-9. [PMID: 23580142 DOI: 10.1161/atvbaha.112.300812] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
OBJECTIVE Liver X receptors (LXRs) are oxysterol-activated nuclear receptors that are highly expressed in macrophages and regulate lipid homeostasis and inflammation. Among putative LXR target genes, lysophosphatidylcholine acyltransferase 3 (LPCAT3) involved in the Lands cycle controls the fatty acid composition at the sn-2 position of glycerophospholipids and, therefore, the availability of fatty acids, such as arachidonic acid (AA), used for eicosanoid synthesis. The aim of our study was to determine whether LXRs could regulate the Lands cycle in human macrophages, to assess the consequences in terms of lipid composition and inflammatory response, and to work out the relative contribution of LPCAT3 to the observed changes. APPROACH AND RESULTS Transcriptomic analysis revealed that LPCAT3 was upregulated by LXR agonists in human macrophages. Accordingly, LXR stimulation significantly increased lysophospholipid acyltransferase activity catalyzed by LPCAT3. Lipidomic analysis demonstrated that LXR activation increased the AA content in the polar lipid fraction, specifically in phosphatidylcholines. The LXR-mediated effects on AA distribution were abolished by LPCAT3 silencing, and a redistribution of AA toward the neutral lipid fraction was observed in this context. Finally, we observed that preconditioning of human macrophages by LXR agonist treatment increased the release of arachidonate-derived eicosanoids, such as prostaglandin E2 and thromboxane after lipopolysaccharide stimulation, with a significant attenuation by LPCAT3 silencing. CONCLUSIONS Altogether, our data demonstrate that the LXR-mediated induction of LPCAT3 primes human macrophages for subsequent eicosanoid secretion by increasing the pool of AA, which can be mobilized from phospholipids.
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Affiliation(s)
- Minako Ishibashi
- Centre de Recherche INSERM UMR866, Université de Bourgogne, Dijon, France
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40
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Abstract
Liver X receptors (LXRs) belong to the nuclear receptor superfamily of ligand-dependent transcription factors. LXRs are activated by oxysterols, metabolites of cholesterol, and therefore act as intracellular sensors of this lipid. There are two LXR genes (α and β) that display distinct tissue/cell expression profiles. LXRs interact with regulatory sequences in target genes as heterodimers with retinoid X receptor. Such direct targets of LXR actions include important genes implicated in the control of lipid homeostasis, particularly reverse cholesterol transport. In addition, LXRs attenuate the transcription of genes associated with the inflammatory response indirectly by transrepression. In this review, we describe recent evidence that both highlights the key roles of LXRs in atherosclerosis and inflammation and provides novel insights into the mechanisms underlying their actions. In addition, we discuss the major limitations of LXRs as therapeutic targets for the treatment of atherosclerosis and how these are being addressed.
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41
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Bruckner M, Dickel D, Singer E, Legler DF. Converse regulation of CCR7-driven human dendritic cell migration by prostaglandin E2and liver X receptor activation. Eur J Immunol 2012; 42:2949-58. [DOI: 10.1002/eji.201242523] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Revised: 07/05/2012] [Accepted: 08/08/2012] [Indexed: 01/09/2023]
Affiliation(s)
- Markus Bruckner
- Biotechnology Institute Thurgau (BITg); University of Konstanz; Kreuzlingen Switzerland
| | - Denise Dickel
- Biotechnology Institute Thurgau (BITg); University of Konstanz; Kreuzlingen Switzerland
| | | | - Daniel F. Legler
- Biotechnology Institute Thurgau (BITg); University of Konstanz; Kreuzlingen Switzerland
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42
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Traversari C, Russo V. Control of the immune system by oxysterols and cancer development. Curr Opin Pharmacol 2012; 12:729-35. [PMID: 22832233 DOI: 10.1016/j.coph.2012.07.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Revised: 07/02/2012] [Accepted: 07/03/2012] [Indexed: 12/20/2022]
Abstract
Oxysterols/oxysterol receptors have been shown to modulate several immune cell subsets, such as macrophages, T-cells and B-cells, neutrophils and dendritic cells (DCs). They participate in the control of several pathologic processes, that is, infectious diseases, atherosclerosis and autoimmunity. Moreover, some oxysterols have also been shown to favor tumor progression by dampening the antitumor immune response. The cellular responses generated by oxysterols depend on the engagement of Liver X Receptor (LXR) α and/or β isoforms, which induce activation of target genes or trans-repression of pro-inflammatory gene transcription. Recently, some reports have described a different mechanism of action of oxysterols, mediated by the engagement of G-Protein Coupled Receptors. Here, we summarize LXR-dependent and LXR-independent responses of oxysterols on immune cells with possible effects on tumor development.
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43
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Nagy L, Szanto A, Szatmari I, Széles L. Nuclear hormone receptors enable macrophages and dendritic cells to sense their lipid environment and shape their immune response. Physiol Rev 2012; 92:739-89. [PMID: 22535896 DOI: 10.1152/physrev.00004.2011] [Citation(s) in RCA: 165] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
A key issue in the immune system is to generate specific cell types, often with opposing activities. The mechanisms of differentiation and subtype specification of immune cells such as macrophages and dendritic cells are critical to understand the regulatory principles and logic of the immune system. In addition to cytokines and pathogens, it is increasingly appreciated that lipid signaling also has a key role in differentiation and subtype specification. In this review we explore how intracellular lipid signaling via a set of transcription factors regulates cellular differentiation, subtype specification, and immune as well as metabolic homeostasis. We introduce macrophages and dendritic cells and then we focus on a group of transcription factors, nuclear receptors, which regulate gene expression upon receiving lipid signals. The receptors we cover are the ones with a recognized physiological function in these cell types and ones which heterodimerize with the retinoid X receptor. These are as follows: the receptor for a metabolite of vitamin A, retinoic acid: retinoic acid receptor (RAR), the vitamin D receptor (VDR), the fatty acid receptor: peroxisome proliferator-activated receptor γ (PPARγ), the oxysterol receptor liver X receptor (LXR), and their obligate heterodimeric partner, the retinoid X receptor (RXR). We discuss how they can get activated and how ligand is generated and eliminated in these cell types. We also explore how activation of a particular target gene contributes to biological functions and how the regulation of individual target genes adds up to the coordination of gene networks. It appears that RXR heterodimeric nuclear receptors provide these cells with a coordinated and interrelated network of transcriptional regulators for interpreting the lipid milieu and the metabolic changes to bring about gene expression changes leading to subtype and functional specification. We also show that these networks are implicated in various immune diseases and are amenable to therapeutic exploitation.
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Affiliation(s)
- Laszlo Nagy
- Department of Biochemistry and Molecular Biology, University of Debrecen, Medical and Health Science Center, Egyetem tér 1, Debrecen, Hungary.
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44
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Biological Roles of Liver X Receptors in Immune Cells. Arch Immunol Ther Exp (Warsz) 2012; 60:235-49. [DOI: 10.1007/s00005-012-0179-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Accepted: 03/16/2012] [Indexed: 12/17/2022]
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45
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Jakobsson T, Treuter E, Gustafsson JÅ, Steffensen KR. Liver X receptor biology and pharmacology: new pathways, challenges and opportunities. Trends Pharmacol Sci 2012; 33:394-404. [PMID: 22541735 DOI: 10.1016/j.tips.2012.03.013] [Citation(s) in RCA: 235] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 03/05/2012] [Accepted: 03/26/2012] [Indexed: 01/12/2023]
Abstract
Nuclear receptors (NRs) are master regulators of transcriptional programs that integrate the homeostatic control of almost all biological processes. Their direct mode of ligand regulation and genome interaction is at the core of modern pharmacology. The two liver X receptors LXRα and LXRβ are among the emerging newer drug targets within the NR family. LXRs are best known as nuclear oxysterol receptors and physiological regulators of lipid and cholesterol metabolism that also act in an anti-inflammatory way. Because LXRs control diverse pathways in development, reproduction, metabolism, immunity and inflammation, they have potential as therapeutic targets for diseases as diverse as lipid disorders, atherosclerosis, chronic inflammation, autoimmunity, cancer and neurodegenerative diseases. Recent insights into LXR signaling suggest future targeting strategies aiming at increasing LXR subtype and pathway selectivity. This review discusses the current status of our understanding of LXR biology and pharmacology, with an emphasis on the molecular aspects of LXR signaling that constitute the potential of LXRs as drug targets.
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Affiliation(s)
- Tomas Jakobsson
- Center for Biosciences, Department of Biosciences and Nutrition, Karolinska Institutet, S-14183 Stockholm, Sweden
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46
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Draper DW, Gowdy KM, Madenspacher JH, Wilson RH, Whitehead GS, Nakano H, Pandiri AR, Foley JF, Remaley AT, Cook DN, Fessler MB. ATP binding cassette transporter G1 deletion induces IL-17-dependent dysregulation of pulmonary adaptive immunity. THE JOURNAL OF IMMUNOLOGY 2012; 188:5327-36. [PMID: 22539789 DOI: 10.4049/jimmunol.1101605] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Mice with genetic deletion of the cholesterol transporter ATP binding cassette G1 (ABCG1) have pulmonary lipidosis and enhanced innate immune responses in the airway. Whether ABCG1 regulates adaptive immune responses to the environment is unknown. To this end, Abcg1(+/+) and Abcg1(-/-) mice were sensitized to OVA via the airway using low-dose LPS as an adjuvant, and then challenged with OVA aerosol. Naive Abcg1(-/-) mice displayed increased B cells, CD4(+) T cells, CD8(+) T cells, and dendritic cells (DCs) in lung and lung-draining mediastinal lymph nodes, with lung CD11b(+) DCs displaying increased CD80 and CD86. Upon allergen sensitization and challenge, the Abcg1(-/-) airway, compared with Abcg1(+/+), displayed reduced Th2 responses (IL-4, IL-5, eosinophils), increased neutrophils and IL-17, but equivalent airway hyperresponsiveness. Reduced Th2 responses were also found using standard i.p. OVA sensitization with aluminum hydroxide adjuvant. Mediastinal lymph nodes from airway-sensitized Abcg1(-/-) mice produced reduced IL-5 upon ex vivo OVA challenge. Abcg1(-/-) CD4(+) T cells displayed normal ex vivo differentiation, whereas Abcg1(-/-) DCs were found paradoxically to promote Th2 polarization. Th17 cells, IL-17(+) γδT cells, and IL-17(+) neutrophils were all increased in Abcg1(-/-) lungs, suggesting Th17 and non-Th17 sources of IL-17 excess. Neutralization of IL-17 prior to challenge normalized eosinophils and reduced neutrophilia in the Abcg1(-/-) airway. We conclude that Abcg1(-/-) mice display IL-17-mediated suppression of eosinophilia and enhancement of neutrophilia in the airway following allergen sensitization and challenge. These findings identify ABCG1 as a novel integrator of cholesterol homeostasis and adaptive immune programs.
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Affiliation(s)
- David W Draper
- Laboratory of Respiratory Biology, Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, USA
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47
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Dushkin MI. Macrophage/foam cell is an attribute of inflammation: Mechanisms of formation and functional role. BIOCHEMISTRY (MOSCOW) 2012; 77:327-38. [DOI: 10.1134/s0006297912040025] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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48
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Azzam KM, Fessler MB. Crosstalk between reverse cholesterol transport and innate immunity. Trends Endocrinol Metab 2012; 23:169-78. [PMID: 22406271 PMCID: PMC3338129 DOI: 10.1016/j.tem.2012.02.001] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 01/30/2012] [Accepted: 02/01/2012] [Indexed: 02/06/2023]
Abstract
Although lipid metabolism and host defense are widely considered to be very divergent disciplines, compelling evidence suggests that host cell handling of self- and microbe-derived (e.g. lipopolysaccharide, LPS) lipids may have common evolutionary roots, and that they indeed may be inseparable processes. The innate immune response and the homeostatic network controlling cellular sterol levels are now known to regulate each other reciprocally, with important implications for several common diseases, including atherosclerosis. In the present review we discuss recent discoveries that provide new insight into the bidirectional crosstalk between reverse cholesterol transport and innate immunity, and highlight the broader implications of these findings for the development of therapeutics.
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Affiliation(s)
- Kathleen M Azzam
- Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
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49
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Tsakiris I, Torocsik D, Gyongyosi A, Dozsa A, Szatmari I, Szanto A, Soos G, Nemes Z, Igali L, Marton I, Takats Z, Nagy L, Dezso B. Carboxypeptidase-M is regulated by lipids and CSFs in macrophages and dendritic cells and expressed selectively in tissue granulomas and foam cells. J Transl Med 2012; 92:345-61. [PMID: 22157720 PMCID: PMC3290762 DOI: 10.1038/labinvest.2011.168] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Granulomatous inflammations, characterized by the presence of activated macrophages (MAs) forming epithelioid cell (EPC) clusters, are usually easy to recognize. However, in ambiguous cases the use of a MA marker that expresses selectively in EPCs may be needed. Here, we report that carboxypeptidase-M (CPM), a MA-differentiation marker, is preferentially induced in EPCs of all granuloma types studied, but not in resting MAs. As CPM is not expressed constitutively in MAs, this allows utilization of CPM-immunohistochemistry in diagnostics of minute granuloma detection when dense non-granulomatous MAs are also present. Despite this rule, hardly any detectable CPM was found in advanced/active tubercle caseous disease, albeit in early tuberculosis granuloma, MAs still expressed CPM. Indeed, in vitro both the CPM-protein and -mRNA became downregulated when MAs were infected with live mycobacteria. In vitro, MA-CPM transcript is neither induced remarkably by interferon-γ, known to cause classical MA activation, nor by IL-4, an alternative MA activator. Instead, CPM is selectively expressed in lipid-laden MAs, including the foam cells of atherosclerotic plaques, xanthomatous lesions and lipid pneumonias. By using serum, rich in lipids, and low-density lipoprotein (LDL) or VLDL, CPM upregulation could be reproduced in vitro in monocyte-derived MAs both at transcriptional and protein levels, and the increase is repressed under lipid-depleted conditions. The microarray analyses support the notion that CPM induction correlates with a robust progressive increase in CPM gene expression during monocyte to MA maturation and dendritic cell (DC) differentiation mediated by granulocyte-MA-colony-stimulating factor+IL-4. M-CSF alone also induced CPM. These results collectively indicate that CPM upregulation in MAs is preferentially associated with increased lipid uptake, and exposure to CSF, features of EPCs, also. Therefore, CPM-immunohistochemistry is useful for granuloma and foam MA detections in tissue sections. Furthermore, the present data offer CPM for the first time to be a novel marker and cellular player in lipid uptake and/or metabolism of MAs by promoting foam cell formation.
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Affiliation(s)
- Ioannis Tsakiris
- Department of Pathology, University of Debrecen, Medical and Health Science Center, Debrecen, Hungary,Department of Dental Microbiology and Oral Pathology, Dental Faculty, University of Debrecen, Debrecen, Hungary
| | - Daniel Torocsik
- Department of Biochemistry and Molecular Biology, University of Debrecen, Medical and Health Science Center, Debrecen, Hungary,Department of Dermatology, University of Debrecen, Medical and Health Science Center, Debrecen, Hungary
| | - Adrienn Gyongyosi
- Department of Biochemistry and Molecular Biology, University of Debrecen, Medical and Health Science Center, Debrecen, Hungary
| | - Aniko Dozsa
- Department of Biochemistry and Molecular Biology, University of Debrecen, Medical and Health Science Center, Debrecen, Hungary
| | - Istvan Szatmari
- Department of Biochemistry and Molecular Biology, University of Debrecen, Medical and Health Science Center, Debrecen, Hungary
| | - Attila Szanto
- Department of Biochemistry and Molecular Biology, University of Debrecen, Medical and Health Science Center, Debrecen, Hungary
| | - Gyorgyike Soos
- Department of Pathology, University of Debrecen, Medical and Health Science Center, Debrecen, Hungary
| | - Zoltan Nemes
- Department of Pathology, University of Debrecen, Medical and Health Science Center, Debrecen, Hungary
| | - Laszlo Igali
- Department of Cellular Pathology, Norfolk and Norwich University Hospitals, Norwich, UK
| | - Ildiko Marton
- Department of Dental Microbiology and Oral Pathology, Dental Faculty, University of Debrecen, Debrecen, Hungary
| | - Zoltan Takats
- Department of Pediatrics, Semmelweis University, Budapest, Hungary
| | - Laszlo Nagy
- Department of Biochemistry and Molecular Biology, University of Debrecen, Medical and Health Science Center, Debrecen, Hungary
| | - Balazs Dezso
- Department of Pathology, University of Debrecen, Medical and Health Science Center, Debrecen, Hungary,Department of Dental Microbiology and Oral Pathology, Dental Faculty, University of Debrecen, Debrecen, Hungary,Department of Dermatology, University of Debrecen, Medical and Health Science Center, Debrecen, Hungary,Department of Pathology, University of Debrecen, Medical and Health Science Center, POB 24, Debrecen 4032, Hungary. E-mail:
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50
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Pehkonen P, Welter-Stahl L, Diwo J, Ryynänen J, Wienecke-Baldacchino A, Heikkinen S, Treuter E, Steffensen KR, Carlberg C. Genome-wide landscape of liver X receptor chromatin binding and gene regulation in human macrophages. BMC Genomics 2012; 13:50. [PMID: 22292898 PMCID: PMC3295715 DOI: 10.1186/1471-2164-13-50] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Accepted: 01/31/2012] [Indexed: 12/15/2022] Open
Abstract
Background The liver X receptors (LXRs) are oxysterol sensing nuclear receptors with multiple effects on metabolism and immune cells. However, the complete genome-wide cistrome of LXR in cells of human origin has not yet been provided. Results We performed ChIP-seq in phorbol myristate acetate-differentiated THP-1 cells (macrophage-type) after stimulation with the potent synthetic LXR ligand T0901317 (T09). Microarray gene expression analysis was performed in the same cellular model. We identified 1357 genome-wide LXR locations (FDR < 1%), of which 526 were observed after T09 treatment. De novo analysis of LXR binding sequences identified a DR4-type element as the major motif. On mRNA level T09 up-regulated 1258 genes and repressed 455 genes. Our results show that LXR actions are focused on 112 genomic regions that contain up to 11 T09 target genes per region under the control of highly stringent LXR binding sites with individual constellations for each region. We could confirm that LXR controls lipid metabolism and transport and observed a strong association with apoptosis-related functions. Conclusions This first report on genome-wide binding of LXR in a human cell line provides new insights into the transcriptional network of LXR and its target genes with their link to physiological processes, such as apoptosis. The gene expression microarray and sequence data have been submitted collectively to the NCBI Gene Expression Omnibus http://www.ncbi.nlm.nih.gov/geo under accession number GSE28319.
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Affiliation(s)
- Petri Pehkonen
- School of Medicine, Institute of Biomedicine, University of Eastern Finland, FIN-70210 Kuopio, Finland
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