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Ohno R, Mainka M, Kirchhoff R, Hartung NM, Schebb NH. Sterol Derivatives Specifically Increase Anti-Inflammatory Oxylipin Formation in M2-like Macrophages by LXR-Mediated Induction of 15-LOX. Molecules 2024; 29:1745. [PMID: 38675565 PMCID: PMC11052137 DOI: 10.3390/molecules29081745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 03/29/2024] [Accepted: 04/07/2024] [Indexed: 04/28/2024] Open
Abstract
The understanding of the role of LXR in the regulation of macrophages during inflammation is emerging. Here, we show that LXR agonist T09 specifically increases 15-LOX abundance in primary human M2 macrophages. In time- and dose-dependent incubations with T09, an increase of 3-fold for ALOX15 and up to 15-fold for 15-LOX-derived oxylipins was observed. In addition, LXR activation has no or moderate effects on the abundance of macrophage marker proteins such as TLR2, TLR4, PPARγ, and IL-1RII, as well as surface markers (CD14, CD86, and CD163). Stimulation of M2-like macrophages with FXR and RXR agonists leads to moderate ALOX15 induction, probably due to side activity on LXR. Finally, desmosterol, 24(S),25-Ep cholesterol and 22(R)-OH cholesterol were identified as potent endogenous LXR ligands leading to an ALOX15 induction. LXR-mediated ALOX15 regulation is a new link between the two lipid mediator classes sterols, and oxylipins, possibly being an important tool in inflammatory regulation through anti-inflammatory oxylipins.
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Affiliation(s)
| | | | | | | | - Nils Helge Schebb
- Chair of Food Chemistry, Faculty of Mathematics and Natural Sciences, University of Wuppertal, Gaußstr. 20, 42119 Wuppertal, Germany
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2
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Dragoljevic D, Lee MKS, Pernes G, Morgan PK, Louis C, Shihata W, Huynh K, Kochetkova AA, Bell PW, Mellett NA, Meikle PJ, Lancaster GI, Kraakman MJ, Nagareddy PR, Hanaoka BY, Wicks IP, Murphy AJ. Administration of an LXR agonist promotes atherosclerotic lesion remodelling in murine inflammatory arthritis. Clin Transl Immunology 2023; 12:e1446. [PMID: 37091327 PMCID: PMC10113696 DOI: 10.1002/cti2.1446] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 02/21/2023] [Accepted: 03/31/2023] [Indexed: 04/25/2023] Open
Abstract
Objectives The leading cause of mortality in patients with rheumatoid arthritis is atherosclerotic cardiovascular disease (CVD). We have shown that murine arthritis impairs atherosclerotic lesion regression, because of cellular cholesterol efflux defects in haematopoietic stem and progenitor cells (HSPCs), causing monocytosis and impaired atherosclerotic regression. Therefore, we hypothesised that improving cholesterol efflux using a Liver X Receptor (LXR) agonist would improve cholesterol efflux and improve atherosclerotic lesion regression in arthritis. Methods Ldlr -/- mice were fed a western-type diet for 14 weeks to initiate atherogenesis, then switched to a chow diet to induce lesion regression and divided into three groups; (1) control, (2) K/BxN serum transfer inflammatory arthritis (K/BxN) or (3) K/BxN arthritis and LXR agonist T0901317 daily for 2 weeks. Results LXR activation during murine inflammatory arthritis completely restored atherosclerotic lesion regression in arthritic mice, evidenced by reduced lesion size, macrophage abundance and lipid content. Mechanistically, serum from arthritic mice promoted foam cell formation, demonstrated by increased cellular lipid accumulation in macrophages and paralleled by a reduction in mRNA of the cholesterol efflux transporters Abca1, Abcg1 and Apoe. T0901317 reduced lipid loading and increased Abca1 and Abcg1 expression in macrophages exposed to arthritic serum and increased ABCA1 levels in atherosclerotic lesions of arthritic mice. Moreover, arthritic clinical score was also attenuated with T0901317. Conclusion Taken together, we show that the LXR agonist T0901317 rescues impaired atherosclerotic lesion regression in murine arthritis because of enhanced cholesterol efflux transporter expression and reduced foam cell development in atherosclerotic lesions.
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Affiliation(s)
- Dragana Dragoljevic
- Division of ImmunometabolismBaker Heart and Diabetes InstituteMelbourneVICAustralia
| | - Man Kit Sam Lee
- Division of ImmunometabolismBaker Heart and Diabetes InstituteMelbourneVICAustralia
| | - Gerard Pernes
- Division of ImmunometabolismBaker Heart and Diabetes InstituteMelbourneVICAustralia
| | - Pooranee K Morgan
- Division of ImmunometabolismBaker Heart and Diabetes InstituteMelbourneVICAustralia
| | - Cynthia Louis
- Inflammation DivisionWalter and Eliza Hall Institute of Medical ResearchParkvilleVICAustralia
- Rheumatology UnitRoyal Melbourne HospitalMelbourneVICAustralia
| | - Waled Shihata
- Division of ImmunometabolismBaker Heart and Diabetes InstituteMelbourneVICAustralia
| | - Kevin Huynh
- Division of ImmunometabolismBaker Heart and Diabetes InstituteMelbourneVICAustralia
| | - Arina A Kochetkova
- Division of ImmunometabolismBaker Heart and Diabetes InstituteMelbourneVICAustralia
| | - Patrick W Bell
- Division of ImmunometabolismBaker Heart and Diabetes InstituteMelbourneVICAustralia
| | - Natalie A Mellett
- Division of ImmunometabolismBaker Heart and Diabetes InstituteMelbourneVICAustralia
| | - Peter J Meikle
- Division of ImmunometabolismBaker Heart and Diabetes InstituteMelbourneVICAustralia
| | - Graeme I Lancaster
- Division of ImmunometabolismBaker Heart and Diabetes InstituteMelbourneVICAustralia
- Department of ImmunologyMonash UniversityMelbourneVICAustralia
| | - Michael J Kraakman
- Division of ImmunometabolismBaker Heart and Diabetes InstituteMelbourneVICAustralia
| | | | - Beatriz Y Hanaoka
- Department of SurgeryOhio State University Wexner Medical CenterColumbusOHUSA
| | - Ian P Wicks
- Inflammation DivisionWalter and Eliza Hall Institute of Medical ResearchParkvilleVICAustralia
- Rheumatology UnitRoyal Melbourne HospitalMelbourneVICAustralia
| | - Andrew J Murphy
- Division of ImmunometabolismBaker Heart and Diabetes InstituteMelbourneVICAustralia
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3
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Liang YH, Luo YH, Chen IS, Lin HR. Engelheptanoxides behave as liver X receptor α agonists. Med Chem Res 2023. [DOI: 10.1007/s00044-023-03016-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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4
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Li Y, Xie HQ, Guo TL, Liu Y, Zhang W, Ma H, Ma D, Xu L, Yu S, Chen G, Ji J, Jiang S, Zhao B. Subacute exposure to dechlorane 602 dysregulates gene expression and immunity in the gut of mice. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 249:114462. [PMID: 38321681 DOI: 10.1016/j.ecoenv.2022.114462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 12/07/2022] [Accepted: 12/21/2022] [Indexed: 02/08/2024]
Abstract
Dechlorane 602 (Dec 602) has biomagnification potential. Our previous studies suggested that exposure to Dec 602 for 7 days induced colonic inflammation even after 7 days of recovery. To shed some light on the underlying mechanisms, disturbances of gut immunity and gene expression were further studied. Adult C57BL/6 mice were administered orally with Dec 602 for 7 days, then allowed to recover for another 7 days. Colonic type 3 innate lymphoid cells (ILC3s) in lamina propria lymphocytes (LPLs) and lymphocytes in mesenteric lymph nodes (MLNs) were examined by flow cytometry. Expressions of genes in the gut were determined by RNA-Seq. It was found that Dec 602 exposure up-regulated the percentage of CD4+ T cells in MLNs. The mean fluorescent intensity (MFI) of interleukin (IL)- 22 in LPLs was decreased, while the MFI of IL-17a as well as the percentage of IL-17a+ ILC3s in LPLs were increased after exposure to Dec 602. Genes involved in the formation of blood vessels and epithelial-mesenchymal transition were up-regulated by Dec 602. Ingenuity pathway analysis of differentially expressed genes predicted that exposure to Dec 602 resulted in the activation of liver X receptor/retinoid X receptor (LXR/RXR) and suppression of muscle contractility. Our results, on one hand, verified that the toxic effects of Dec 602 on gut immunity could last for at least 14 days, and on the other hand, these results predicted other adverse effects of Dec 602, such as muscle dysfunction. Overall, our studies provided insights for the further investigation of Dec 602 and other emerging environmental pollutants.
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Affiliation(s)
- Yunping Li
- School of environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Heidi Qunhui Xie
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tai L Guo
- Department of Veterinary Biomedical Sciences, University of Georgia, Athens, GA 30602, USA
| | - Yin Liu
- School of environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
| | - Wanglong Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China; College of Life Sciences, Qufu Normal University, Qufu, Shandong 273165, China
| | - Hui Ma
- State Key Laboratory of Natural Medicines & Jiangsu Provincial Key Laboratory of TCM Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu 211198, China
| | - Dan Ma
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Li Xu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shuyuan Yu
- Environment and Health Department, Shenzhen Center for Disease Control and Prevention, Shenzhen, Guangdong 518055, China
| | - Guomin Chen
- Environment and Health Department, Shenzhen Center for Disease Control and Prevention, Shenzhen, Guangdong 518055, China
| | - Jiajia Ji
- Environment and Health Department, Shenzhen Center for Disease Control and Prevention, Shenzhen, Guangdong 518055, China
| | - Shuai Jiang
- Environment and Health Department, Shenzhen Center for Disease Control and Prevention, Shenzhen, Guangdong 518055, China
| | - Bin Zhao
- School of environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
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5
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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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Goel D, Vohora D. Liver X receptors and skeleton: Current state-of-knowledge. Bone 2021; 144:115807. [PMID: 33333244 DOI: 10.1016/j.bone.2020.115807] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 11/26/2020] [Accepted: 12/11/2020] [Indexed: 12/25/2022]
Abstract
The liver X receptors (LXR) is a nuclear receptor that acts as a prominent regulator of lipid homeostasis and inflammatory response. Its therapeutic effectiveness against various diseases like Alzheimer's disease and atherosclerosis has been investigated in detail. Emerging pieces of evidence now reveal that LXR is also a crucial modulator of bone remodeling. However, the molecular mechanisms underlying the pharmacological actions of LXR on the skeleton and its role in osteoporosis are poorly understood. Therefore, in the current review, we highlight LXR and its actions through different molecular pathways modulating skeletal homeostasis. The studies described in this review propound that LXR in association with estrogen, PTH, PPARγ, RXR hedgehog, and canonical Wnt signaling regulates osteoclastogenesis and bone resorption. It regulates RANKL-induced expression of c-Fos, NFATc1, and NF-κB involved in osteoclast differentiation. Additionally, several studies suggest suppression of RANKL-induced osteoclast differentiation by synthetic LXR ligands. Given the significance of modulation of LXR in various physiological and pathological settings, our findings indicate that therapeutic targeting of LXR might potentially prevent or treat osteoporosis and improve bone quality.
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Affiliation(s)
- Divya Goel
- Department of Pharmacology, School of Pharmaceutical Education and Research (SPER), Jamia Hamdard, New Delhi 110062, India
| | - Divya Vohora
- Department of Pharmacology, School of Pharmaceutical Education and Research (SPER), Jamia Hamdard, New Delhi 110062, India.
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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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8
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5 α,6 α-Epoxyphytosterols and 5 α,6 α-Epoxycholesterol Increase Nitrosative Stress and Inflammatory Cytokine Production in Rats on Low-Cholesterol Diet. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:4751803. [PMID: 32587660 PMCID: PMC7298340 DOI: 10.1155/2020/4751803] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 05/26/2020] [Indexed: 11/18/2022]
Abstract
Objective Oxidized cholesterol derivatives are compounds with proven atherogenic and mutagenic effects. However, little is known about the effect of oxidized plant sterol derivatives (oxyphytosterols), whose structure is similar to the one of oxycholesterols. Our previous studies indicate that they have a similar profile of action, e.g., both exacerbate disorder of lipid metabolism and oxidative stress in experimental animals. The aim of the present study was to assess the effect of epoxycholesterol and epoxyphytosterols (mainly sitosterol) on the severity of nitrosative stress and the concentration of selected proinflammatory cytokines in blood and liver tissue of rats on a low-cholesterol diet. Material and Methods. Forty-five male Wistar rats were fed with feed containing 5α,6α-epoxyphytosterols (ES group, n: 15), 5α,6α-epoxycholesterol (ECh group, n: 15), and oxysterol-free feed (C group, n: 15) for 90 days (daily dose of oxysterols: 10 mg/kg). At the end of the experiment, nitrotyrosine, TNF-α, IL-1β, IL-6, and lipid metabolism parameters were determined in blood serum. Furthermore, nitrotyrosine, TNF-α, cholesterol, and triglyceride content were determined in liver homogenates. Results Serum nitrotyrosine, IL-1β, and TNF-α concentrations as well as TNF-α content in the liver were significantly higher in both groups exposed to oxysterols (ECh and ES groups) as compared to the C group. The serum IL-6 level and nitrotyrosine content in the liver were significantly higher in the ECh group, as compared to the C and ES groups. There was evidence to support the dyslipidemic effect of studied compounds. Conclusions The results indicate that oxidized plant sterols have a similar toxicity profile to that of oxycholesterols, including nitrosative stress induction, proinflammatory effect, and impaired lipid metabolism.
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Mouzat K, Chudinova A, Polge A, Kantar J, Camu W, Raoul C, Lumbroso S. Regulation of Brain Cholesterol: What Role Do Liver X Receptors Play in Neurodegenerative Diseases? Int J Mol Sci 2019; 20:E3858. [PMID: 31398791 PMCID: PMC6720493 DOI: 10.3390/ijms20163858] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 08/06/2019] [Accepted: 08/06/2019] [Indexed: 12/11/2022] Open
Abstract
Liver X Receptors (LXR) alpha and beta are two members of nuclear receptor superfamily documented as endogenous cholesterol sensors. Following conversion of cholesterol in oxysterol, both LXR isoforms detect intracellular concentrations and act as transcription factors to promote expression of target genes. Among their numerous physiological roles, they act as central cholesterol-lowering factors. In the central nervous system (CNS), cholesterol has been shown to be an essential determinant of brain function, particularly as a major constituent of myelin and membranes. In the brain, LXRs act as cholesterol central regulators, and, beyond this metabolic function, LXRs have additional roles such as providing neuroprotective effects and lowering neuroinflammation. In many neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS), Alzheimer's disease (AD), and multiple sclerosis (MS), dysregulations of cholesterol and oxysterol have been reported. In this paper, we propose to focus on recent advances in the knowledge of the LXRs roles on brain cholesterol and oxysterol homeostasis, neuroinflammation, neuroprotection, and their putative involvement in neurodegenerative disorders. We will discuss their potential use as candidates for both molecular diagnosis and as promising pharmacological targets in the treatment of ALS, AD, or MS patients.
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Affiliation(s)
- Kevin Mouzat
- Motoneuron Disease: Pathophysiology and Therapy, The Neuroscience Institute of Montpellier, University of Montpellier, Montpellier, Laboratoire de Biochimie et Biologie Moléculaire, Nimes University Hospital, 30029 Nîmes, France.
| | - Aleksandra Chudinova
- Motoneuron Disease: Pathophysiology and Therapy, The Neuroscience Institute of Montpellier, University of Montpellier, Montpellier, Laboratoire de Biochimie et Biologie Moléculaire, Nimes University Hospital, 30029 Nîmes, France
| | - Anne Polge
- Laboratoire de Biochimie et Biologie Moléculaire, Nimes University Hospital, University of Montpellier, 30029 Nîmes, France
| | - Jovana Kantar
- Motoneuron Disease: Pathophysiology and Therapy, The Neuroscience Institute of Montpellier, University of Montpellier, Montpellier, Laboratoire de Biochimie et Biologie Moléculaire, Nimes University Hospital, 30029 Nîmes, France
| | - William Camu
- ALS Reference Center, Montpellier University Hospital and University of Montpellier, Inserm UMR1051, 34000 Montpellier, France
| | - Cédric Raoul
- The Neuroscience Institute of Montpellier, Inserm UMR1051, University of Montpellier, 34091 Montpellier, France
| | - Serge Lumbroso
- Motoneuron Disease: Pathophysiology and Therapy, The Neuroscience Institute of Montpellier, University of Montpellier, Montpellier, Laboratoire de Biochimie et Biologie Moléculaire, Nimes University Hospital, 30029 Nîmes, France
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Dallel S, Tauveron I, Brugnon F, Baron S, Lobaccaro JMA, Maqdasy S. Liver X Receptors: A Possible Link between Lipid Disorders and Female Infertility. Int J Mol Sci 2018; 19:ijms19082177. [PMID: 30044452 PMCID: PMC6121373 DOI: 10.3390/ijms19082177] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 07/18/2018] [Accepted: 07/19/2018] [Indexed: 12/16/2022] Open
Abstract
A close relationship exists between cholesterol and female reproductive physiology. Indeed, cholesterol is crucial for steroid synthesis by ovary and placenta, and primordial for cell structure during folliculogenesis. Furthermore, oxysterols, cholesterol-derived ligands, play a potential role in oocyte maturation. Anomalies of cholesterol metabolism are frequently linked to infertility. However, little is known about the molecular mechanisms. In parallel, increasing evidence describing the biological roles of liver X receptors (LXRs) in the regulation of steroid synthesis and inflammation, two processes necessary for follicle maturation and ovulation. Both of the isoforms of LXRs and their bona fide ligands are present in the ovary. LXR-deficient mice develop late sterility due to abnormal oocyte maturation and increased oocyte atresia. These mice also have an ovarian hyper stimulation syndrome in response to gonadotropin stimulation. Hence, further studies are necessary to explore their specific roles in oocyte, granulosa, and theca cells. LXRs also modulate estrogen signaling and this could explain the putative protective role of the LXRs in breast cancer growth. Altogether, clinical studies would be important for determining the physiological relevance of LXRs in reproductive disorders in women.
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Affiliation(s)
- Sarah Dallel
- Université Clermont Auvergne, GReD, CNRS UMR 6293, INSERM U1103, 28, Place Henri Dunant, BP38, F63001 Clermont-Ferrand, France.
- Centre de Recherche en Nutrition Humaine d'Auvergne, 58 Boulevard Montalembert, F-63009 Clermont-Ferrand, France.
- Service d'Endocrinologie, Diabétologie et Maladies Métaboliques, CHU Clermont Ferrand, Hôpital Gabriel Montpied, F-63003 Clermont-Ferrand, France.
| | - Igor Tauveron
- Université Clermont Auvergne, GReD, CNRS UMR 6293, INSERM U1103, 28, Place Henri Dunant, BP38, F63001 Clermont-Ferrand, France.
- Service d'Endocrinologie, Diabétologie et Maladies Métaboliques, CHU Clermont Ferrand, Hôpital Gabriel Montpied, F-63003 Clermont-Ferrand, France.
| | - Florence Brugnon
- Université Clermont Auvergne, ImoST, INSERM U1240, 58, rue Montalembert, BP184, F63005 Clermont-Ferrand, France.
- CHU Clermont Ferrand, Assistance Médicale à la Procréation-CECOS, Hôpital Estaing, Place Lucie et Raymond Aubrac, F-63003 Clermont-Ferrand CEDEX 1, France.
| | - Silvère Baron
- Université Clermont Auvergne, GReD, CNRS UMR 6293, INSERM U1103, 28, Place Henri Dunant, BP38, F63001 Clermont-Ferrand, France.
- Centre de Recherche en Nutrition Humaine d'Auvergne, 58 Boulevard Montalembert, F-63009 Clermont-Ferrand, France.
| | - Jean Marc A Lobaccaro
- Université Clermont Auvergne, GReD, CNRS UMR 6293, INSERM U1103, 28, Place Henri Dunant, BP38, F63001 Clermont-Ferrand, France.
- Centre de Recherche en Nutrition Humaine d'Auvergne, 58 Boulevard Montalembert, F-63009 Clermont-Ferrand, France.
| | - Salwan Maqdasy
- Université Clermont Auvergne, GReD, CNRS UMR 6293, INSERM U1103, 28, Place Henri Dunant, BP38, F63001 Clermont-Ferrand, France.
- Centre de Recherche en Nutrition Humaine d'Auvergne, 58 Boulevard Montalembert, F-63009 Clermont-Ferrand, France.
- Service d'Endocrinologie, Diabétologie et Maladies Métaboliques, CHU Clermont Ferrand, Hôpital Gabriel Montpied, F-63003 Clermont-Ferrand, France.
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Jennelle LT, Dandekar AP, Magoro T, Hahn YS. Immunometabolic Signaling Pathways Contribute to Macrophage and Dendritic Cell Function. Crit Rev Immunol 2018; 36:379-394. [PMID: 28605345 DOI: 10.1615/critrevimmunol.2017018803] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Understanding of antigen-presenting cell (APC) participation in tissue inflammation and metabolism has advanced through numerous studies using systems biology approaches. Previously unrecognized connections between these research areas have been elucidated in the context of inflammatory disease involving innate and adaptive immune responses. A new conceptual framework bridges APC biology, metabolism, and cytokines in the generation of effective T-cell responses. Exploring these connections is paramount to addressing the rising tide of multi-organ system diseases, particularly chronic diseases associated with metabolic syndrome, infection, and cancer. Focused research in these areas will aid the development of strategies to harness and manipulate innate immunology to improve vaccine development, anti-viral, anti-inflammatory, and anti-tumor therapies. This review highlights recent advances in APC "immunometabolism" specifically related to chronic viral and metabolic disease in humans. The goal of this review is to develop an abridged and consolidated outlook on recent thematic updates to APC immunometabolism in the areas of regulation and crosstalk between metabolic and inflammatory signaling and the integrated stress response and how these signals dictate APC function in providing T-cell activation Signal 3.
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Affiliation(s)
- Lucas T Jennelle
- Department of Microbiology, Beirne B. Carter Center for Immunology Research, University of Virginia, Charlottesville, VA, USA
| | - Aditya P Dandekar
- Department of Microbiology, Beirne B. Carter Center for Immunology Research, University of Virginia, Charlottesville, VA, USA
| | - Tshifhiwa Magoro
- Department of Microbiology, Beirne B. Carter Center for Immunology Research, University of Virginia, Charlottesville, VA, USA
| | - Young S Hahn
- Department of Microbiology, Beirne B. Carter Center for Immunology Research, University of Virginia, Charlottesville, VA, USA
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12
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Tavazoie MF, Pollack I, Tanqueco R, Ostendorf BN, Reis BS, Gonsalves FC, Kurth I, Andreu-Agullo C, Derbyshire ML, Posada J, Takeda S, Tafreshian KN, Rowinsky E, Szarek M, Waltzman RJ, Mcmillan EA, Zhao C, Mita M, Mita A, Chmielowski B, Postow MA, Ribas A, Mucida D, Tavazoie SF. LXR/ApoE Activation Restricts Innate Immune Suppression in Cancer. Cell 2018; 172:825-840.e18. [PMID: 29336888 DOI: 10.1016/j.cell.2017.12.026] [Citation(s) in RCA: 303] [Impact Index Per Article: 50.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 11/14/2017] [Accepted: 12/19/2017] [Indexed: 12/15/2022]
Abstract
Therapeutic harnessing of adaptive immunity via checkpoint inhibition has transformed the treatment of many cancers. Despite unprecedented long-term responses, most patients do not respond to these therapies. Immunotherapy non-responders often harbor high levels of circulating myeloid-derived suppressor cells (MDSCs)-an immunosuppressive innate cell population. Through genetic and pharmacological approaches, we uncovered a pathway governing MDSC abundance in multiple cancer types. Therapeutic liver-X nuclear receptor (LXR) agonism reduced MDSC abundance in murine models and in patients treated in a first-in-human dose escalation phase 1 trial. MDSC depletion was associated with activation of cytotoxic T lymphocyte (CTL) responses in mice and patients. The LXR transcriptional target ApoE mediated these effects in mice, where LXR/ApoE activation therapy elicited robust anti-tumor responses and also enhanced T cell activation during various immune-based therapies. We implicate the LXR/ApoE axis in the regulation of innate immune suppression and as a target for enhancing the efficacy of cancer immunotherapy in patients.
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Affiliation(s)
- Masoud F Tavazoie
- Laboratory of Systems Cancer Biology, The Rockefeller University, New York, NY, USA.
| | - Ilana Pollack
- Laboratory of Systems Cancer Biology, The Rockefeller University, New York, NY, USA
| | - Raissa Tanqueco
- Laboratory of Systems Cancer Biology, The Rockefeller University, New York, NY, USA
| | - Benjamin N Ostendorf
- Laboratory of Systems Cancer Biology, The Rockefeller University, New York, NY, USA
| | - Bernardo S Reis
- Laboratory of Mucosal Immunology, The Rockefeller University, New York, NY, USA
| | | | | | | | - Mark L Derbyshire
- Laboratory of Systems Cancer Biology, The Rockefeller University, New York, NY, USA
| | - Jessica Posada
- Laboratory of Systems Cancer Biology, The Rockefeller University, New York, NY, USA
| | | | - Kimia N Tafreshian
- Laboratory of Systems Cancer Biology, The Rockefeller University, New York, NY, USA
| | | | - Michael Szarek
- Rgenix, New York, NY, USA; School of Public Health, Downstate Medical Center, Brooklyn, NY, USA
| | | | - Elizabeth A Mcmillan
- Laboratory of Systems Cancer Biology, The Rockefeller University, New York, NY, USA
| | - Connie Zhao
- Laboratory of Systems Cancer Biology, The Rockefeller University, New York, NY, USA
| | - Monica Mita
- Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Alain Mita
- Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | | | - Michael A Postow
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Weill Cornell Medical College, New York, NY, USA
| | - Antoni Ribas
- Department of Medicine, University of California, Los Angeles, CA, USA
| | - Daniel Mucida
- Laboratory of Mucosal Immunology, The Rockefeller University, New York, NY, USA.
| | - Sohail F Tavazoie
- Laboratory of Systems Cancer Biology, The Rockefeller University, New York, NY, USA.
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13
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Gargiulo S, Testa G, Gamba P, Staurenghi E, Poli G, Leonarduzzi G. Oxysterols and 4-hydroxy-2-nonenal contribute to atherosclerotic plaque destabilization. Free Radic Biol Med 2017; 111:140-150. [PMID: 28057601 DOI: 10.1016/j.freeradbiomed.2016.12.037] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 12/22/2016] [Accepted: 12/24/2016] [Indexed: 12/31/2022]
Abstract
A growing bulk of evidence suggests that cholesterol oxidation products, known as oxysterols, and 4-hydroxy-2-nonenal (HNE), the major proatherogenic components of oxidized low density lipoproteins (oxLDLs), significantly contribute to atherosclerotic plaque progression and destabilization, with eventual plaque rupture. These oxidized lipids are involved in various key steps of this complex process, mainly thanks to their ability to induce inflammation, oxidative stress, and apoptosis. This review summarizes the current knowledge of the effects induced by these compounds on vascular cells, after their accumulation in the arterial wall and in the atherosclerotic plaque.
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Affiliation(s)
- Simona Gargiulo
- Department of Clinical and Biological Sciences, University of Torino, San Luigi Hospital, 10043 Orbassano, Torino, Italy
| | - Gabriella Testa
- Department of Clinical and Biological Sciences, University of Torino, San Luigi Hospital, 10043 Orbassano, Torino, Italy
| | - Paola Gamba
- Department of Clinical and Biological Sciences, University of Torino, San Luigi Hospital, 10043 Orbassano, Torino, Italy
| | - Erica Staurenghi
- Department of Clinical and Biological Sciences, University of Torino, San Luigi Hospital, 10043 Orbassano, Torino, Italy
| | - Giuseppe Poli
- Department of Clinical and Biological Sciences, University of Torino, San Luigi Hospital, 10043 Orbassano, Torino, Italy
| | - Gabriella Leonarduzzi
- Department of Clinical and Biological Sciences, University of Torino, San Luigi Hospital, 10043 Orbassano, Torino, Italy.
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14
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Marwarha G, Raza S, Hammer K, Ghribi O. 27-hydroxycholesterol: A novel player in molecular carcinogenesis of breast and prostate cancer. Chem Phys Lipids 2017; 207:108-126. [PMID: 28583434 DOI: 10.1016/j.chemphyslip.2017.05.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 05/31/2017] [Accepted: 05/31/2017] [Indexed: 12/13/2022]
Abstract
Several studies have suggested an etiological role for hypercholesterolemia in the pathogenesis of breast cancer and prostate cancer (PCa). However, the molecular mechanisms that underlie and mediate the hypercholesterolemia-fostered increased risk for breast cancer and PCa are yet to be determined. The discovery that the most abundant cholesterol oxidized metabolite in the plasma, 27 hydroxycholesterol (27-OHC), is a selective estrogen receptor modulator (SERM) and an agonist of Liver X receptors (LXR) partially fills the void in our understanding and knowledge of the mechanisms that may link hypercholesterolemia to development and progression of breast cancer and PCa. The wide spectrum and repertoire of SERM and LXR-dependent effects of 27-OHC in the context of all facets and aspects of breast cancer and prostate cancer biology are reviewed in this manuscript in a very comprehensive manner. This review highlights recent findings pertaining to the role of 27-OHC in breast cancer and PCa and delineates the signaling mechanisms involved in the governing of different facets of tumor biology, that include tumor cell proliferation, epithelial-mesenchymal transition (EMT), as well as tumor cell invasion, migration, and metastasis. We also discuss the limitations of contemporary studies and lack of our comprehension of the entire gamut of effects exerted by 27-OHC that may be relevant to the pathogenesis of breast cancer and PCa. We unveil and propose potential future directions of research that may further our understanding of the role of 27-OHC in breast cancer and PCa and help design therapeutic interventions against endocrine therapy-resistant breast cancer and PCa.
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Affiliation(s)
- Gurdeep Marwarha
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, 58202, USA
| | - Shaneabbas Raza
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, 58202, USA
| | - Kimberly Hammer
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, 58202, USA; Department of Veteran Affairs, Fargo VA Health Care System, Fargo, North Dakota 58102, USA
| | - Othman Ghribi
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, 58202, USA.
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15
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Danford ID, Verkuil LD, Choi DJ, Collins DW, Gudiseva HV, Uyhazi KE, Lau MK, Kanu LN, Grant GR, Chavali VRM, O'Brien JM. Characterizing the "POAGome": A bioinformatics-driven approach to primary open-angle glaucoma. Prog Retin Eye Res 2017; 58:89-114. [PMID: 28223208 PMCID: PMC5464971 DOI: 10.1016/j.preteyeres.2017.02.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 02/03/2017] [Accepted: 02/10/2017] [Indexed: 01/10/2023]
Abstract
Primary open-angle glaucoma (POAG) is a genetically, physiologically, and phenotypically complex neurodegenerative disorder. This study addressed the expanding collection of genes associated with POAG, referred to as the "POAGome." We used bioinformatics tools to perform an extensive, systematic literature search and compiled 542 genes with confirmed associations with POAG and its related phenotypes (normal tension glaucoma, ocular hypertension, juvenile open-angle glaucoma, and primary congenital glaucoma). The genes were classified according to their associated ocular tissues and phenotypes, and functional annotation and pathway analyses were subsequently performed. Our study reveals that no single molecular pathway can encompass the pathophysiology of POAG. The analyses suggested that inflammation and senescence may play pivotal roles in both the development and perpetuation of the retinal ganglion cell degeneration seen in POAG. The TGF-β signaling pathway was repeatedly implicated in our analyses, suggesting that it may be an important contributor to the manifestation of POAG in the anterior and posterior segments of the globe. We propose a molecular model of POAG revolving around TGF-β signaling, which incorporates the roles of inflammation and senescence in this disease. Finally, we highlight emerging molecular therapies that show promise for treating POAG.
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Affiliation(s)
- Ian D Danford
- Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Lana D Verkuil
- Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Daniel J Choi
- Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - David W Collins
- Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Harini V Gudiseva
- Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Katherine E Uyhazi
- Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Marisa K Lau
- Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Levi N Kanu
- Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Gregory R Grant
- Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA, Penn Center for Bioinformatics, University of Pennsylvania, Philadelphia, PA, USA
| | - Venkata R M Chavali
- Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, 19104, USA.
| | - Joan M O'Brien
- Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, 19104, USA
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25-hydroxycholesterol promotes RANKL-induced osteoclastogenesis through coordinating NFATc1 and Sp1 complex in the transcription of miR-139-5p. Biochem Biophys Res Commun 2017; 485:736-741. [DOI: 10.1016/j.bbrc.2017.02.118] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 02/23/2017] [Indexed: 01/30/2023]
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17
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Ouedraogo ZG, Fouache A, Trousson A, Baron S, Lobaccaro JMA. Role of the liver X receptors in skin physiology: Putative pharmacological targets in human diseases. Chem Phys Lipids 2017; 207:59-68. [PMID: 28259649 DOI: 10.1016/j.chemphyslip.2017.02.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 02/22/2017] [Accepted: 02/22/2017] [Indexed: 02/07/2023]
Abstract
Liver X receptors (LXRs) are members of the nuclear receptor superfamily that have been shown to regulate various physiological functions such as lipid metabolism and cholesterol homeostasis. Concordant reports have elicited the possibility to target them to cure many human diseases including arteriosclerosis, cancer, arthritis, and diabetes. The high relevance of modulating LXR activities to treat numerous skin diseases, mainly those with exacerbated inflammation processes, contrasts with the lack of approved therapeutic use. This review makes an assessment to sum up the findings regarding the physiological roles of LXRs in skin and help progress towards the therapeutic and safe management of their activities. It focuses on the possible pharmacological targeting of LXRs to cure or prevent selected skin diseases.
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Affiliation(s)
- Zangbéwendé Guy Ouedraogo
- Université Clermont Auvergne, GReD, CNRS UMR 6293, INSERM U1103, 28, place Henri Dunant, BP38, F63001, Clermont-Ferrand, France; Centre de Recherche en Nutrition Humaine d'Auvergne, 58 Boulevard Montalembert, F-63009 Clermont-Ferrand, France
| | - Allan Fouache
- Université Clermont Auvergne, GReD, CNRS UMR 6293, INSERM U1103, 28, place Henri Dunant, BP38, F63001, Clermont-Ferrand, France; Centre de Recherche en Nutrition Humaine d'Auvergne, 58 Boulevard Montalembert, F-63009 Clermont-Ferrand, France
| | - Amalia Trousson
- Université Clermont Auvergne, GReD, CNRS UMR 6293, INSERM U1103, 28, place Henri Dunant, BP38, F63001, Clermont-Ferrand, France; Centre de Recherche en Nutrition Humaine d'Auvergne, 58 Boulevard Montalembert, F-63009 Clermont-Ferrand, France
| | - Silvère Baron
- Université Clermont Auvergne, GReD, CNRS UMR 6293, INSERM U1103, 28, place Henri Dunant, BP38, F63001, Clermont-Ferrand, France; Centre de Recherche en Nutrition Humaine d'Auvergne, 58 Boulevard Montalembert, F-63009 Clermont-Ferrand, France.
| | - Jean-Marc A Lobaccaro
- Université Clermont Auvergne, GReD, CNRS UMR 6293, INSERM U1103, 28, place Henri Dunant, BP38, F63001, Clermont-Ferrand, France; Centre de Recherche en Nutrition Humaine d'Auvergne, 58 Boulevard Montalembert, F-63009 Clermont-Ferrand, France.
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18
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Relationship of Liver X Receptors α and Endoglin Levels in Serum and Placenta with Preeclampsia. PLoS One 2016; 11:e0163742. [PMID: 27736929 PMCID: PMC5063368 DOI: 10.1371/journal.pone.0163742] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 09/13/2016] [Indexed: 11/19/2022] Open
Abstract
Background Liver X receptor alpha (LXRα) and endoglin have been postulated to play roles in trophoblast invasion and lipid metabolic disturbances. However, the relationship between LXRα and endoglin levels in serum and placenta of patients with preeclampsia remains poorly understood. The objective of this study was to identify correlations between LXRα, endoglin and preeclampsia and provide new feasible methods of clinical prediction and treatment for preeclampsia. Methods We enrolled 45 patients with preeclampsia (24 with moderate preeclampsia and 21 with severe preeclampsia) and 15 normal pregnant women (control group) who were admitted to the Department of Obstetrics of the General Hospital of Beijing Command between October 2012 and July 2013 in this study. Serum and placental LXRα and endoglin levels were analyzed by enzyme-linked immunosorbent assay, real-time quantitative PCR, tissue microarray and immunohistochemistry. Results Serum and placental LXRα and endoglin levels were significantly higher in patients with preeclampsia than those in control group (P<0.05, each). Moreover, patients with severe preeclampsia displayed significantly higher LXRα and endoglin levels than those with moderate preeclampsia (P<0.05, each). The LXRα sensitivity, specificity and positive and negative predictive values were 66.00%, 80.00%, 89.19% and 48.48%, respectively, while those of endoglin levels were 62.00%, 85.00%, 91.18% and 47.22%, respectively. LXRα and endoglin levels in serum and placenta from patients with preeclampsia were positively correlated (serum: r = 0.486, P<0.01; placenta: r = 0.569, P<0.01). Conclusions Elevated LXRα and endoglin levels may be associated with preeclampsia pathogenesis and development and could be used as potential predictors for this disorder.
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Gargiulo S, Gamba P, Testa G, Leonarduzzi G, Poli G. The role of oxysterols in vascular ageing. J Physiol 2016; 594:2095-113. [PMID: 26648329 DOI: 10.1113/jp271168] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 11/06/2015] [Indexed: 12/24/2022] Open
Abstract
The ageing endothelium progressively loses its remarkable and crucial ability to maintain homeostasis of the vasculature, as it acquires a proinflammatory phenotype. Cellular and structural changes gradually accumulate in the blood vessels, and markedly in artery walls. Most changes in aged arteries are comparable to those occurring during the atherogenic process, the latter being more marked: pro-oxidant and proinflammatory molecules, mainly deriving from or triggered by oxidized low density lipoproteins (oxLDLs), are undoubtedly a major driving force of this process. Oxysterols, quantitatively relevant components of oxLDLs, are likely candidate molecules in the pathogenesis of vascular ageing, because of their marked pro-oxidant, proinflammatory and proapoptotic properties. An increasing bulk of experimental data point to the contribution of a variety of oxysterols of pathophysiological interest, also in the age-related genesis of endothelium dysfunction, intimal thickening due to lipid accumulation, and smooth muscle cell migration and arterial stiffness due to increasing collagen deposition and calcification. This review provides an updated analysis of the molecular mechanisms whereby oxysterols accumulating in the wall of ageing blood vessels may 'activate' endothelial and monocytic cells, through expression of an inflammatory phenotype, and 'convince' smooth muscle cells to proliferate, migrate and, above all, to act as fibroblast-like cells.
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Affiliation(s)
- Simona Gargiulo
- Department of Clinical and Biological Sciences, University of Torino, San Luigi Hospital, 10043 Orbassano, Torino, Italy
| | - Paola Gamba
- Department of Clinical and Biological Sciences, University of Torino, San Luigi Hospital, 10043 Orbassano, Torino, Italy
| | - Gabriella Testa
- Department of Clinical and Biological Sciences, University of Torino, San Luigi Hospital, 10043 Orbassano, Torino, Italy
| | - Gabriella Leonarduzzi
- Department of Clinical and Biological Sciences, University of Torino, San Luigi Hospital, 10043 Orbassano, Torino, Italy
| | - Giuseppe Poli
- Department of Clinical and Biological Sciences, University of Torino, San Luigi Hospital, 10043 Orbassano, Torino, Italy
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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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21
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Vanmierlo T, Bogie JF, Mailleux J, Vanmol J, Lütjohann D, Mulder M, Hendriks JJ. Plant sterols: Friend or foe in CNS disorders? Prog Lipid Res 2015; 58:26-39. [DOI: 10.1016/j.plipres.2015.01.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 01/15/2015] [Accepted: 01/15/2015] [Indexed: 12/21/2022]
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Ren S, Ning Y. Sulfation of 25-hydroxycholesterol regulates lipid metabolism, inflammatory responses, and cell proliferation. Am J Physiol Endocrinol Metab 2014; 306:E123-30. [PMID: 24302009 PMCID: PMC3920008 DOI: 10.1152/ajpendo.00552.2013] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Intracellular lipid accumulation, inflammatory responses, and subsequent apoptosis are the major pathogenic events of metabolic disorders, including atherosclerosis and nonalcoholic fatty liver diseases. Recently, a novel regulatory oxysterol, 5-cholesten-3b, 25-diol 3-sulfate (25HC3S), has been identified, and hydroxysterol sulfotransferase 2B1b (SULT2B1b) has been elucidated as the key enzyme for its biosynthesis from 25-hydroxycholesterol (25HC) via oxysterol sulfation. The product 25HC3S and the substrate 25HC have been shown to coordinately regulate lipid metabolism, inflammatory responses, and cell proliferation in vitro and in vivo. 25HC3S decreases levels of the nuclear liver oxysterol receptor (LXR) and sterol regulatory element-binding proteins (SREBPs), inhibits SREBP processing, subsequently downregulates key enzymes in lipid biosynthesis, decreases intracellular lipid levels in hepatocytes and THP-1-derived macrophages, prevents apoptosis, and promotes cell proliferation in liver tissues. Furthermore, 25HC3S increases nuclear PPARγ and cytosolic IκBα and decreases nuclear NF-κB levels and proinflammatory cytokine expression and secretion when cells are challenged with LPS and TNFα. In contrast to 25HC3S, 25HC, a known LXR ligand, increases nuclear LXR and decreases nuclear PPARs and cytosol IκBα levels. In this review, we summarize our recent findings, including the discovery of the regulatory oxysterol sulfate, its biosynthetic pathway, and its functional mechanism. We also propose that oxysterol sulfation functions as a regulatory signaling pathway.
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Affiliation(s)
- Shunlin Ren
- Departments of Medicine, McGuire Veterans Affairs Medical Center/Virginia Commonwealth University, Richmond, Virginia
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Higham A, Lea S, Plumb J, Maschera B, Simpson K, Ray D, Singh D. The role of the liver X receptor in chronic obstructive pulmonary disease. Respir Res 2013; 14:106. [PMID: 24118845 PMCID: PMC3852990 DOI: 10.1186/1465-9921-14-106] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Accepted: 09/25/2013] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND There is a need for novel anti-inflammatory therapies to treat COPD. The liver X receptor (LXR) is a nuclear hormone receptor with anti-inflammatory properties. METHODS We investigated LXR gene and protein expression levels in alveolar macrophages and whole lung tissue from COPD patients and controls, the effect of LXR activation on the suppression of inflammatory mediators from LPS stimulated COPD alveolar macrophages, and the effect of LXR activation on the induction of genes associated with alternative macrophage polarisation. RESULTS The levels of LXR mRNA were significantly increased in whole lung tissue extracts in COPD patients and smokers compared to non-smokers. The expression of LXR protein was significantly increased in small airway epithelium and alveolar epithelium in COPD patients compared to controls. No differences in LXR mRNA and protein levels were observed in alveolar macrophages between patient groups. The LXR agonist GW3965 significantly induced the expression of the LXR dependent genes ABCA1 and ABCG1 in alveolar macrophage cultures. In LPS stimulated alveolar macrophages, GW3965 suppressed the production of CXCL10 and CCL5, whilst stimulating IL-10 production. CONCLUSIONS GW3965 did not significantly suppress the production of TNFα, IL-1β, or CXCL8. Our major finding is that LXR activation has anti-inflammatory effects on CXC10, CCL5 and IL-10 production from alveolar macrophages.
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Affiliation(s)
- Andrew Higham
- The University of Manchester, NIHR Translational Research Facility, University Hospital of South Manchester Foundation Trust, Southmoor Road, Manchester M23 9LT, UK
| | - Simon Lea
- The University of Manchester, NIHR Translational Research Facility, University Hospital of South Manchester Foundation Trust, Southmoor Road, Manchester M23 9LT, UK
| | - Jonathan Plumb
- The University of Manchester, NIHR Translational Research Facility, University Hospital of South Manchester Foundation Trust, Southmoor Road, Manchester M23 9LT, UK
| | - Barbara Maschera
- GlaxoSmithKline, Respiratory CEDD, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, UK
| | - Karen Simpson
- GlaxoSmithKline, Respiratory CEDD, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, UK
| | - David Ray
- The University of Manchester, NIHR Translational Research Facility, University Hospital of South Manchester Foundation Trust, Southmoor Road, Manchester M23 9LT, UK
| | - Dave Singh
- The University of Manchester, NIHR Translational Research Facility, University Hospital of South Manchester Foundation Trust, Southmoor Road, Manchester M23 9LT, UK
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Bellezza I, Roberti R, Gatticchi L, Del Sordo R, Rambotti MG, Marchetti MC, Sidoni A, Minelli A. A novel role for Tm7sf2 gene in regulating TNFα expression. PLoS One 2013; 8:e68017. [PMID: 23935851 PMCID: PMC3720723 DOI: 10.1371/journal.pone.0068017] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 05/24/2013] [Indexed: 12/11/2022] Open
Abstract
We have explored the role of Tm7sf2 gene, which codifies for 3β-hydroxysterol Δ14-reductase, an endoplasmic reticulum resident protein, in the sensitivity to endoplasmic reticulum stress and in the resulting inflammatory response. We used mouse embryonic fibroblasts, derived from Tm7sf2+/+ and Tm7sf2−/− mice, to determine the in vitro effects of thapsigargin on NF-κB activation. Our results show that the Tm7sf2 gene controls the launch of the unfolded protein response and presides an anti-inflammatory loop thus its absence correlates with NF-κB activation and TNFα up-regulation. Our data also show that Tm7sf2 gene regulates liver X receptor activation and its absence inhibits LXR signalling. By expressing the hTm7sf2 gene in KO MEFs and observing a reduced NF-κB activation, we have confirmed that Tm7sf2 gene is linked to NF-κB activation. Finally we used genetically modified mice in an in vivo model of ER stress and of inflammation. Our results show a significant increase in renal TNFα expression after tunicamycin exposure and in the oedematogenic response in Tm7sf2−/− mice. In conclusion, we have shown that the Tm7sf2 gene, to date involved only in cholesterol biosynthesis, also controls an anti-inflammatory loop thereby confirming the existence of cross talk between metabolic pathways and inflammatory response.
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Affiliation(s)
- Ilaria Bellezza
- Dipartimento di Medicina Sperimentale e Scienze Biochimiche, Sezione di Biochimica Cellulare, Università di Perugia, Perugia, Italia.
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25
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Nelson ER, Wardell SE, McDonnell DP. The molecular mechanisms underlying the pharmacological actions of estrogens, SERMs and oxysterols: implications for the treatment and prevention of osteoporosis. Bone 2013; 53:42-50. [PMID: 23168292 PMCID: PMC3552054 DOI: 10.1016/j.bone.2012.11.011] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 10/19/2012] [Accepted: 11/12/2012] [Indexed: 12/12/2022]
Abstract
Estrogen therapy and hormone therapy are effective options for the prevention and treatment of osteoporosis, although because of their significant side effect profile, long term use for these applications is not recommended. Whereas SERMs (Selective Estrogen Receptor Modulators) exhibit a more favorable side effect profile, the currently available medicines in this class are substantially less effective in bone than classical estrogens. However, the results of substantial efforts that have gone into defining the mechanisms that underlie the pharmacology of estrogens, antiestrogens and SERMs have informed the development of the next generation of SERMs and have led to the development of TSECs (Tissue Selective Estrogen Complexes), a new class of ER-modulator. Further, the recent determination that the oxysterol 27-hydroxycholesterol functions as an endogenous SERM has highlighted an unexpected link between hypercholesterolemia and bone biology and must be considered in any discussions of ER-pharmacology. This review considers the most recent progress in our understanding of ER pharmacology and how this has and will be translated into new medicines for the treatment and prevention of osteoporosis.
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Affiliation(s)
- Erik R Nelson
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA
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Pan W, Stone KP, Hsuchou H, Manda VK, Zhang Y, Kastin AJ. Cytokine signaling modulates blood-brain barrier function. Curr Pharm Des 2013; 17:3729-40. [PMID: 21834767 DOI: 10.2174/138161211798220918] [Citation(s) in RCA: 164] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 08/30/2011] [Accepted: 09/26/2011] [Indexed: 02/06/2023]
Abstract
The blood-brain barrier (BBB) provides a vast interface for cytokines to affect CNS function. The BBB is a target for therapeutic intervention. It is essential, therefore, to understand how cytokines interact with each other at the level of the BBB and how secondary signals modulate CNS functions beyond the BBB. The interactions between cytokines and lipids, however, have not been fully addressed at the level of the BBB. Here, we summarize current understanding of the localization of cytokine receptors and transporters in specific membrane microdomains, particularly lipid rafts, on the luminal (apical) surface of the microvascular endothelial cells composing the BBB. We then illustrate the clinical context of cytokine effects on the BBB by neuroendocrine regulation and amplification of inflammatory signals. Two unusual aspects discussed are signaling crosstalk by different classes of cytokines and genetic regulation of drug efflux transporters. We also introduce a novel area of focus on how cytokines may act through nuclear hormone receptors to modulate efflux transporters and other targets. A specific example discussed is the ATP-binding cassette transporter-1 (ABCA-1) that regulates lipid metabolism. Overall, cytokine signaling at the level of the BBB is a crucial feature of the dynamic regulation that can rapidly change BBB function and affect brain health and disease.
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Affiliation(s)
- Weihong Pan
- Blood-Brain Barrier Group, Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA 70808, USA
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27
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Alba G, Reyes ME, Santa-María C, Ramírez R, Geniz I, Jiménez J, Martín-Nieto J, Pintado E, Sobrino F. Transcription of liver X receptor is down-regulated by 15-deoxy-Δ(12,14)-prostaglandin J(2) through oxidative stress in human neutrophils. PLoS One 2012; 7:e42195. [PMID: 23115616 PMCID: PMC3480349 DOI: 10.1371/journal.pone.0042195] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Accepted: 07/04/2012] [Indexed: 01/04/2023] Open
Abstract
Liver X receptors (LXRs) are ligand-activated transcription factors of the nuclear receptor superfamily. They play important roles in controlling cholesterol homeostasis and as regulators of inflammatory gene expression and innate immunity, by blunting the induction of classical pro-inflammatory genes. However, opposite data have also been reported on the consequences of LXR activation by oxysterols, resulting in the specific production of potent pro-inflammatory cytokines and reactive oxygen species (ROS). The effect of the inflammatory state on the expression of LXRs has not been studied in human cells, and constitutes the main aim of the present work. Our data show that when human neutrophils are triggered with synthetic ligands, the synthesis of LXRα mRNA became activated together with transcription of the LXR target genes ABCA1, ABCG1 and SREBP1c. An inflammatory mediator, 15-deoxy-Δ12,14-prostaglandin J2 (15dPGJ2), hindered T0901317-promoted induction of LXRα mRNA expression together with transcription of its target genes in both neutrophils and human macrophages. This down-regulatory effect was dependent on the release of reactive oxygen species elicited by 15dPGJ2, since it was enhanced by pro-oxidant treatment and reversed by antioxidants, and was also mediated by ERK1/2 activation. Present data also support that the 15dPGJ2-induced serine phosphorylation of the LXRα molecule is mediated by ERK1/2. These results allow to postulate that down-regulation of LXR cellular levels by pro-inflammatory stimuli might be involved in the development of different vascular diseases, such as atherosclerosis.
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Affiliation(s)
- Gonzalo Alba
- Departamento de Bioquímica Médica y Biología Molecular, Universidad de Sevilla, Sevilla, Spain
| | - María Edith Reyes
- Departamento de Bioquímica Médica y Biología Molecular, Universidad de Sevilla, Sevilla, Spain
| | - Consuelo Santa-María
- Departamento de Bioquímica y Biología Molecular, Universidad de Sevilla, Sevilla, Spain
| | - Remedios Ramírez
- Departamento de Bioquímica Médica y Biología Molecular, Universidad de Sevilla, Sevilla, Spain
| | - Isabel Geniz
- Distrito Sanitario Sevilla Norte, Servicio Andaluz de Salud, Sevilla, Spain
| | - Juan Jiménez
- Departamento de Bioquímica Médica y Biología Molecular, Universidad de Sevilla, Sevilla, Spain
| | - José Martín-Nieto
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
| | - Elízabeth Pintado
- Departamento de Bioquímica Médica y Biología Molecular, Universidad de Sevilla, Sevilla, Spain
| | - Francisco Sobrino
- Departamento de Bioquímica Médica y Biología Molecular, Universidad de Sevilla, Sevilla, Spain
- * E-mail:
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Oxysterols and their cellular effectors. Biomolecules 2012; 2:76-103. [PMID: 24970128 PMCID: PMC4030866 DOI: 10.3390/biom2010076] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Revised: 02/03/2012] [Accepted: 02/07/2012] [Indexed: 11/23/2022] Open
Abstract
Oxysterols are oxidized 27-carbon cholesterol derivatives or by-products of cholesterol biosynthesis, with a spectrum of biologic activities. Several oxysterols have cytotoxic and pro-apoptotic activities, the ability to interfere with the lateral domain organization, and packing of membrane lipids. These properties may account for their suggested roles in the pathology of diseases such as atherosclerosis, age-onset macular degeneration and Alzheimer’s disease. Oxysterols also have the capacity to induce inflammatory responses and play roles in cell differentiation processes. The functions of oxysterols as intermediates in the synthesis of bile acids and steroid hormones, and as readily transportable forms of sterol, are well established. Furthermore, their actions as endogenous regulators of gene expression in lipid metabolism via liver X receptors and the Insig (insulin-induced gene) proteins have been investigated in detail. The cytoplasmic oxysterol-binding protein (OSBP) homologues form a group of oxysterol/cholesterol sensors that has recently attracted a lot of attention. However, their mode of action is, as yet, poorly understood. Retinoic acid receptor-related orphan receptors (ROR) α and γ, and Epstein-Barr virus induced gene 2 (EBI2) have been identified as novel oxysterol receptors, revealing new physiologic oxysterol effector mechanisms in development, metabolism, and immunity, and evoking enhanced interest in these compounds in the field of biomedicine.
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Leonarduzzi G, Gamba P, Gargiulo S, Biasi F, Poli G. Inflammation-related gene expression by lipid oxidation-derived products in the progression of atherosclerosis. Free Radic Biol Med 2012; 52:19-34. [PMID: 22037514 DOI: 10.1016/j.freeradbiomed.2011.09.031] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 09/16/2011] [Accepted: 09/24/2011] [Indexed: 12/31/2022]
Abstract
Vascular areas of atherosclerotic development persist in a state of inflammation, and any further inflammatory stimulus in the subintimal area elicits a proatherogenic response; this alters the behavior of the artery wall cells and recruits further inflammatory cells. In association with the inflammatory response, oxidative events are also involved in the development of atherosclerotic plaques. It is now unanimously recognized that lipid oxidation-derived products are key players in the initiation and progression of atherosclerotic lesions. Oxidized lipids, derived from oxidatively modified low-density lipoproteins (LDLs), which accumulate in the intima, strongly modulate inflammation-related gene expression, through involvement of various signaling pathways. In addition, considerable evidence supports a proatherogenic role of a large group of potent bioactive lipids called eicosanoids, which derive from oxidation of arachidonic acid, a component of membrane phospholipids. Of note, LDL lipid oxidation products might regulate eicosanoid production, modulating the enzymatic degradation of arachidonic acid by cyclooxygenases and lipoxygenases; these enzymes might also directly contribute to LDL oxidation. This review provides a comprehensive overview of current knowledge on signal transduction pathways and inflammatory gene expression, modulated by lipid oxidation-derived products, in the progression of atherosclerosis.
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Mogilenko DA, Kudriavtsev IV, Trulioff AS, Shavva VS, Dizhe EB, Missyul BV, Zhakhov AV, Ischenko AM, Perevozchikov AP, Orlov SV. Modified low density lipoprotein stimulates complement C3 expression and secretion via liver X receptor and Toll-like receptor 4 activation in human macrophages. J Biol Chem 2011; 287:5954-68. [PMID: 22194611 DOI: 10.1074/jbc.m111.289322] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Complement C3 is a pivotal component of three cascades of complement activation. C3 is expressed in human atherosclerotic lesions and is involved in atherogenesis. However, the mechanism of C3 accumulation in atherosclerotic lesions is not well elucidated. We show that acetylated low density lipoprotein and oxidized low density lipoprotein (oxLDL) increase C3 gene expression and protein secretion by human macrophages. Modified LDL (mLDL)-mediated activation of C3 expression mainly depends on liver X receptor (LXR) and partly on Toll-like receptor 4 (TLR4), whereas C3 secretion is increased due to TLR4 activation by mLDL. LXR agonist TO901317 stimulates C3 gene expression in human monocyte-macrophage cells but not in human hepatoma (HepG2) cells. We find LXR-responsive element inside of the promoter region of the human C3 gene, which binds to LXRβ in macrophages but not in HepG2 cells. We show that C3 expression and secretion is decreased in IL-4-treated (M2) and increased in IFNγ/LPS-stimulated (M1) human macrophages as compared with resting macrophages. LXR agonist TO901317 potentiates LPS-induced C3 gene expression and protein secretion in macrophages, whereas oxLDL differently modulates LPS-mediated regulation of C3 in M1 or M2 macrophages. Treatment of human macrophages with anaphylatoxin C3a results in stimulation of C3 transcription and secretion as well as increased oxLDL accumulation and augmented oxLDL-mediated up-regulation of the C3 gene. These data provide a novel mechanism of C3 gene regulation in macrophages and suggest new aspects of cross-talk between mLDL, C3, C3a, and TLR4 during development of atherosclerotic lesions.
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Affiliation(s)
- Denis A Mogilenko
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, St. Petersburg 197376, Russia.
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Kittayaruksakul S, Soodvilai S, Asavapanumas N, Muanprasat C, Chatsudthipong V. Liver X receptor activation downregulates organic anion transporter 1 (OAT1) in the renal proximal tubule. Am J Physiol Renal Physiol 2011; 302:F552-60. [PMID: 22169006 DOI: 10.1152/ajprenal.00341.2011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Liver X receptors (LXRs) play an important role in the regulation of cholesterol by regulating several transporters. In this study, we investigated the role of LXRs in the regulation of human organic anion transporter 1 (hOAT1), a major transporter localized in the basolateral membrane of the renal proximal tubule. Exposure of renal S2 cells expressing hOAT1 to LXR agonists (TO901317 and GW3965) and their endogenous ligand [22(R)-hydroxycholesterol] led to the inhibition of hOAT1-mediated [(14)C]PAH uptake. This inhibition was abolished by coincubation of the above agonists with 22(S)-hydroxycholesterol, an LXR antagonist. Moreover, it was found that the effect of LXR agonists was not mediated by changes in intracellular cholesterol levels. Interestingly, the inhibitory effect of LXRs was enhanced in the presence of 9-cis retinoic acid, a retinoic X receptor agonist. Kinetic analysis revealed that LXR activation decreased the maximum rate of PAH transport (J(max)) but had no effect on the affinity of the transporter (K(t)). This result correlated well with data from Western blot analysis, which showed the decrease in hOAT1 expression following LXR activation. Similarly, TO901317 inhibited [(14)C]PAH uptake by the renal cortical slices as well as decreasing mOAT1 protein expression in mouse kidney. Our findings indicated for the first time that hOAT1 was downregulated by LXR activation in the renal proximal tubule.
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Na TY, Lee HJ, Oh HJ, Huh S, Lee IK, Lee MO. Positive Cross-Talk Between Hypoxia Inducible Factor-1α and Liver X Receptor α Induces Formation of Triglyceride-Loaded Foam Cells. Arterioscler Thromb Vasc Biol 2011; 31:2949-56. [DOI: 10.1161/atvbaha.111.235788] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objective—
Atherosclerosis is a chronic and progressive inflammatory disease of the arteries that is characterized by subendothelial accumulation of lipid-rich macrophages, called foam cells. We sought to identify the molecular details of cross-talk between liver X receptor α (LXRα) and hypoxia-inducible factor 1α (HIF-1α) for the formation of triglyceride-rich foam cells under hypoxic conditions.
Methods and Results—
We first observed that expression of LXRα and its target lipogenic genes was time-dependently induced in human primary macrophages and RAW 264.7 cells under hypoxia. Similarly, TO901317, an activator of LXRα, enhanced the expression level and the transcriptional activity of HIF-1α. Second, we demonstrated that LXRα increased HIF-1α protein stability through a physical interaction between the ligand binding domain of LXRα and the oxygen-dependent degradation domain of HIF-1α. Third, we found that the activation of HIF-1α or LXRα synergistically induced triglyceride accumulation in macrophages. Finally, we showed that LXRα and HIF-1α were codistributed in the macrophages of atherosclerotic lesions of patients.
Conclusion—
These results suggest that the positive feed-forward regulation of transcriptional activity and protein stability of LXRα and HIF-1α has an important impact in foam cell formation.
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Affiliation(s)
- Tae-Young Na
- From the College of Pharmacy and Bio-MAX Institute, Seoul National University, Seoul (T.Y.N., H.J.O., M.O.L.); and Department of Internal Medicine and WCU program (H.J.L., I.K.L.), Department of Surgery (S.H.), Kyungpook National University School of Medicine, Daegu, Korea
| | - Hyo-Jeong Lee
- From the College of Pharmacy and Bio-MAX Institute, Seoul National University, Seoul (T.Y.N., H.J.O., M.O.L.); and Department of Internal Medicine and WCU program (H.J.L., I.K.L.), Department of Surgery (S.H.), Kyungpook National University School of Medicine, Daegu, Korea
| | - Hyeon-Jeong Oh
- From the College of Pharmacy and Bio-MAX Institute, Seoul National University, Seoul (T.Y.N., H.J.O., M.O.L.); and Department of Internal Medicine and WCU program (H.J.L., I.K.L.), Department of Surgery (S.H.), Kyungpook National University School of Medicine, Daegu, Korea
| | - Seung Huh
- From the College of Pharmacy and Bio-MAX Institute, Seoul National University, Seoul (T.Y.N., H.J.O., M.O.L.); and Department of Internal Medicine and WCU program (H.J.L., I.K.L.), Department of Surgery (S.H.), Kyungpook National University School of Medicine, Daegu, Korea
| | - In-Kyu Lee
- From the College of Pharmacy and Bio-MAX Institute, Seoul National University, Seoul (T.Y.N., H.J.O., M.O.L.); and Department of Internal Medicine and WCU program (H.J.L., I.K.L.), Department of Surgery (S.H.), Kyungpook National University School of Medicine, Daegu, Korea
| | - Mi-Ock Lee
- From the College of Pharmacy and Bio-MAX Institute, Seoul National University, Seoul (T.Y.N., H.J.O., M.O.L.); and Department of Internal Medicine and WCU program (H.J.L., I.K.L.), Department of Surgery (S.H.), Kyungpook National University School of Medicine, Daegu, Korea
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Nelson ER, DuSell CD, Wang X, Howe MK, Evans G, Michalek RD, Umetani M, Rathmell JC, Khosla S, Gesty-Palmer D, McDonnell DP. The oxysterol, 27-hydroxycholesterol, links cholesterol metabolism to bone homeostasis through its actions on the estrogen and liver X receptors. Endocrinology 2011; 152:4691-705. [PMID: 21933863 PMCID: PMC3230052 DOI: 10.1210/en.2011-1298] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Osteoporosis and age-related bone loss are important public health concerns. Therefore, there is a high level of interest in the development of medical interventions and lifestyle changes that reduce the incidence of osteoporosis and age-related bone loss. Decreased bone mineral density is associated with high cholesterol, and patients on statins have increased bone mineral densities, strongly implicating cholesterol as a negative regulator of bone homeostasis. In this study, using both molecular and pharmacological approaches, we have been able to demonstrate that the primary cholesterol metabolite, 27-hydroxycholesterol, through its actions on both estrogen receptors and liver X receptors, decreases osteoblast differentiation and enhances osteoclastogenesis, resulting in increased bone resorbtion in mice. Induction of the short heterodimer partner protein by estrogens in osteoblasts can attenuate the liver X receptor-mediated actions of 27-hydroxycholesterol in bone. These data establish a mechanistic link between cholesterol and bone quality, highlight an unexpected target of estrogens in osteoblasts, and define a signaling axis, the therapeutic exploitation of which is likely to yield novel antiosteoporotic drugs.
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Affiliation(s)
- Erik R Nelson
- Pharmacology and Cancer Biology, Duke University Medical Center, P.O. Box 3813, Durham, North Carolina 27710, USA
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Kotokorpi P, Venteclef N, Ellis E, Gustafsson JÅ, Mode A. The Human ADFP Gene Is a Direct Liver-X-Receptor (LXR) Target Gene and Differentially Regulated by Synthetic LXR Ligands. Mol Pharmacol 2009; 77:79-86. [DOI: 10.1124/mol.109.059063] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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35
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Erridge C, Webb DJ, Spickett CM. 25-Hydroxycholesterol, 7β-hydroxycholesterol and 7-ketocholesterol upregulate interleukin-8 expression independently of Toll-like receptor 1, 2, 4 or 6 signalling in human macrophages. Free Radic Res 2009; 41:260-6. [PMID: 17364953 DOI: 10.1080/10715760601070091] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Recent studies have shown that Toll-like receptor (TLR)- signalling contributes significantly to the inflammatory events of atherosclerosis. As products of cholesterol oxidation (oxysterols) accumulate within atherosclerotic plaque and have been proposed to contribute to inflammatory signalling in the diseased artery, we investigated the potential of 7-ketocholesterol (7-KC), 7beta-hydroxycholesterol (7beta-HC) and 25-hydroxycholesterol (25-HC) to stimulate inflammatory signalling via the lipid-recognising TLRs 1, 2, 4 and 6. Each oxysterol stimulated secretion of the inflammatory chemokine interleukin-8 (IL-8), but not IkappaBalpha degradation or tumour necrosis factor-alpha release from monocytic THP-1 cells. Transfection of TLR-deficient HEK-293 cells with TLRs 1, 2, 4 or 6 did not increase sensitivity to the tested oxysterols. Moreover, blockade of TLR2 or TLR4 with specific inhibitors did not reduce 25-hydroxycholesterol (25-HC) induced IL-8 release from THP-1 cells. We conclude that although the oxysterols examined in this study may contribute to increased expression of certain inflammatory genes, this occurs by mechanisms independent of TLR signalling.
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Affiliation(s)
- Clett Erridge
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK.
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36
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Mouzat K, Volat F, Baron S, Alves G, Pommier AJC, Volle DH, Marceau G, DeHaze A, Déchelotte P, Duggavathi R, Caira F, Lobaccaro JMA. Absence of nuclear receptors for oxysterols liver X receptor induces ovarian hyperstimulation syndrome in mice. Endocrinology 2009; 150:3369-75. [PMID: 19325005 PMCID: PMC2703512 DOI: 10.1210/en.2008-1519] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Ovarian hyperstimulation syndrome is a frequent complication occurring during in vitro fertilization cycles. It is characterized by a massive ovarian enlargement associated with an accumulation of extra vascular fluid. Here we show that liver X receptor (LXR)-alpha and LXR-beta deficient mice present many clinical and biological signs of ovarian hyperstimulation syndrome: ovarian enlargement, hemorrhagic corpora lutea, increased ovarian vascular permeability, and elevated estradiol. Ovulation stimulation resulted in excessive ovarian response to exogenous gonadotropins because follicle number and estradiol production were higher in transgenic mice. LXR deficiency also leads to perturbations in general inflammatory status, associated with ovarian il-6 deregulation. Upon treatment with the synthetic LXR agonist T09101317, serum estradiol and expression of star and cyp11a1 genes were markedly increased in wild-type mice, showing that LXRs are key regulators of ovarian steroidogenesis. These results suggest that LXRs control the ovulation by regulating endocrine and vascular processes.
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Affiliation(s)
- Kevin Mouzat
- Unité Mixte de Recherche, Centre National de la Recherche Scientifique 6247, Clermont Université, Centre de Recherche en Nutrition Humaine d'Auvergne, 63177 Aubière Cedex, France
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37
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Trousson A, Bernard S, Petit PX, Liere P, Pianos A, El Hadri K, Lobaccaro JMA, Ghandour MS, Raymondjean M, Schumacher M, Massaad C. 25-hydroxycholesterol provokes oligodendrocyte cell line apoptosis and stimulates the secreted phospholipase A2 type IIA via LXR beta and PXR. J Neurochem 2009; 109:945-58. [PMID: 19250336 DOI: 10.1111/j.1471-4159.2009.06009.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In several neurodegenerative diseases of the CNS, oligodendrocytes are implicated in an inflammatory process associated with altered levels of oxysterols and inflammatory enzymes such as secreted phospholipase A2 (sPLA2). In view of the scarce literature related to this topic, we investigated oxysterol effects on these myelinating glial cells. Natural oxysterol 25-hydroxycholesterol (25-OH; 1 and 10 microM) altered oligodendrocyte cell line (158N) morphology and triggered apoptosis (75% of apoptosis after 72 h). These effects were mimicked by 22(S)-OH (1 and 10 microM) which does not activate liver X receptor (LXR) but not by a synthetic LXR ligand (T0901317). Therefore, oxysterol-induced apoptosis appears to be independent of LXR. Interestingly, sPLA2 type IIA (sPLA2-IIA) over-expression partially rescued 158N cells from oxysterol-induced apoptosis. In fact, 25-OH, 24(S)-OH, and T0901317 stimulated sPLA2-IIA promoter and sPLA2 activity in oligodendrocyte cell line. Accordingly, administration of T0901317 to mice enhanced sPLA2 activity in brain extracts by twofold. Short interfering RNA strategy allowed to establish that stimulation of sPLA2-IIA is mediated by pregnane X receptor (PXR) at high oxysterol concentration (10 microM) and by LXR beta at basal oxysterol concentration. Finally, GC coupled to mass spectrometry established that oligodendrocytes contain oxysterols and express their biosynthetic enzymes, suggesting that they may act through autocrine/paracrine mechanism. Our results show the diversity of oxysterol signalling in the CNS and highlight the positive effects of the LXR/PXR pathway which may open new perspectives in the treatment of demyelinating and neurodegenerative diseases.
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Affiliation(s)
- Amalia Trousson
- UMR788, INSERM and University Paris-Sud 11, IFR 93, Le Kremlin-Bicêtre Cedex, France
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38
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Chen PJ, Padgett WT, Moore T, Winnik W, Lambert GR, Thai SF, Hester SD, Nesnow S. Three conazoles increase hepatic microsomal retinoic acid metabolism and decrease mouse hepatic retinoic acid levels in vivo. Toxicol Appl Pharmacol 2009; 234:143-55. [DOI: 10.1016/j.taap.2008.10.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2008] [Revised: 10/02/2008] [Accepted: 10/15/2008] [Indexed: 12/31/2022]
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39
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Ma Y, Xu L, Rodriguez-Agudo D, Li X, Heuman DM, Hylemon PB, Pandak WM, Ren S. 25-Hydroxycholesterol-3-sulfate regulates macrophage lipid metabolism via the LXR/SREBP-1 signaling pathway. Am J Physiol Endocrinol Metab 2008; 295:E1369-79. [PMID: 18854425 PMCID: PMC2603552 DOI: 10.1152/ajpendo.90555.2008] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The oxysterol receptor LXR is a key transcriptional regulator of lipid metabolism. LXR increases expression of SREBP-1, which in turn regulates at least 32 genes involved in lipid synthesis and transport. We recently identified 25-hydroxycholesterol-3-sulfate (25HC3S) as an important regulatory molecule in the liver. We have now studied the effects of 25HC3S and its precursor, 25-hydroxycholesterol (25HC), on lipid metabolism as mediated by the LXR/SREBP-1 signaling in macrophages. Addition of 25HC3S to human THP-1-derived macrophages markedly decreased nuclear LXR protein levels. 25HC3S administration was followed by dose- and time-dependent decreases in SREBP-1 mature protein and mRNA levels. 25HC3S decreased the expression of SREBP-1-responsive genes, acetyl-CoA carboxylase-1, and fatty acid synthase (FAS) as well as HMGR and LDLR, which are key proteins involved in lipid metabolism. Subsequently, 25HC3S decreased intracellular lipids and increased cell proliferation. In contrast to 25HC3S, 25HC acted as an LXR ligand, increasing ABCA1, ABCG1, SREBP-1, and FAS mRNA levels. In the presence of 25HC3S, 25HC, and LXR agonist T0901317, stimulation of LXR targeting gene expression was repressed. We conclude that 25HC3S acts in macrophages as a cholesterol satiety signal, downregulating cholesterol and fatty acid synthetic pathways via inhibition of LXR/SREBP signaling. A possible role of oxysterol sulfation is proposed.
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Affiliation(s)
- Yongjie Ma
- Veterans Affairs McGuire Medical Center/Virginia Commonwealth University, Richmond, VA 23249, USA
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40
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DiBlasio-Smith EA, Arai M, Quinet EM, Evans MJ, Kornaga T, Basso MD, Chen L, Feingold I, Halpern AR, Liu QY, Nambi P, Savio D, Wang S, Mounts WM, Isler JA, Slager AM, Burczynski ME, Dorner AJ, LaVallie ER. Discovery and implementation of transcriptional biomarkers of synthetic LXR agonists in peripheral blood cells. J Transl Med 2008; 6:59. [PMID: 18925943 PMCID: PMC2576083 DOI: 10.1186/1479-5876-6-59] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Accepted: 10/16/2008] [Indexed: 11/29/2022] Open
Abstract
Background LXRs (Liver X Receptor α and β) are nuclear receptors that act as ligand-activated transcription factors. LXR activation causes upregulation of genes involved in reverse cholesterol transport (RCT), including ABCA1 and ABCG1 transporters, in macrophage and intestine. Anti-atherosclerotic effects of synthetic LXR agonists in murine models suggest clinical utility for such compounds. Objective Blood markers of LXR agonist exposure/activity were sought to support clinical development of novel synthetic LXR modulators. Methods Transcript levels of LXR target genes ABCA1 and ABCG1 were measured using quantitative reverse transcriptase/polymerase chain reaction assays (qRT-PCR) in peripheral blood from mice and rats (following a single oral dose) and monkeys (following 7 daily oral doses) of synthetic LXR agonists. LXRα, LXRβ, ABCA1, and ABCG1 mRNA were measured by qRT-PCR in human peripheral blood mononuclear cells (PBMC), monocytes, T- and B-cells treated ex vivo with WAY-252623 (LXR-623), and protein levels in human PBMC were measured by Western blotting. ABCA1/G1 transcript levels in whole-blood RNA were measured using analytically validated assays in human subjects participating in a Phase 1 SAD (Single Ascending Dose) clinical study of LXR-623. Results A single oral dose of LXR agonists induced ABCA1 and ABCG1 transcription in rodent peripheral blood in a dose- and time-dependent manner. Induction of gene expression in rat peripheral blood correlated with spleen expression, suggesting LXR gene regulation in blood has the potential to function as a marker of tissue gene regulation. Transcriptional response to LXR agonist was confirmed in primates, where peripheral blood ABCA1 and ABCG1 levels increased in a dose-dependent manner following oral treatment with LXR-623. Human PBMC, monocytes, T- and B cells all expressed both LXRα and LXRβ, and all cell types significantly increased ABCA1 and ABCG1 expression upon ex vivo LXR-623 treatment. Peripheral blood from a representative human subject receiving a single oral dose of LXR-623 showed significant time-dependent increases in ABCA1 and ABCG1 transcription. Conclusion Peripheral blood cells express LXRα and LXRβ, and respond to LXR agonist treatment by time- and dose-dependently inducing LXR target genes. Transcript levels of LXR target genes in peripheral blood are relevant and useful biological indicators for clinical development of synthetic LXR modulators.
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Affiliation(s)
- Elizabeth A DiBlasio-Smith
- Department of Biological Technologies, Wyeth Research, 35 CambridgePark Drive, Cambridge, MA 02140, USA.
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41
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Myhre AE, Agren J, Dahle MK, Tamburstuen MV, Lyngstadaas SP, Collins AJL, Foster SJ, Thiemermann C, Aasen AO, Wang JE. Liver X receptor is a key regulator of cytokine release in human monocytes. Shock 2008; 29:468-74. [PMID: 17724434 DOI: 10.1097/shk.0b013e31815073cb] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Aberrant regulation of innate immune responses and uncontrolled cytokine bursts are hallmarks of sepsis and endotoxemia. Activation of the nuclear liver X receptor (LXR) was recently demonstrated to suppress inflammatory genes. Our aim was to investigate the expression of LXR in human monocytes under normal and endotoxemic conditions and to study the influence of LXR activation on endotoxin-induced cytokine synthesis and release. Adherent human monocytes or whole blood were pretreated with a synthetic LXR agonist (3-{3-[(2-chloro-3-trifluoromethyl-benzyl)-(2,2-diphenyl-ethyl)-amino]-propoxy}-phenyl)-acetic acid) and subsequently challenged with LPS (from Escherichia coli) or peptidoglycan (from Staphylococcus aureus). Cytokine release was assessed by a Multiplex antibody bead kit, and cytokine mRNA levels were measured by real-time reverse-transcriptase-polymerase chain reaction. We found that LXRalpha mRNA was up-regulated in CD14+ monocytes in LPS-challenged blood, whereas LXRbeta mRNA was not altered. Addition of 3-{3-[(2-chloro-3-trifluoromethyl-benzyl)-(2,2-diphenyl-ethyl)-amino]-propoxy}-phenyl)-acetic acid to monocytes suppressed the LPS-induced release of IL-1beta, IL-6, IL-8, IL-10, IL-12p40, TMF-alpha, macrophage inflammatory protein 1alpha, macrophage inflammatory protein 1beta, and monocyte chemoattractant protein 1 in a concentration-dependent manner. Surprisingly, an accompanying decrease in cytokine mRNA accumulation was not observed. The suppressed cytokine release could not be explained by a diminished transport of mRNA out of the nucleus or a decreased secretion of cytokines. We propose that LXR is a key regulator of cytokine release in LPS-challenged human monocytes, possibly by interfering with translational events.
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Affiliation(s)
- Anders E Myhre
- Institute for Surgical Research, Rikshospitalet-Radiumhospitalet Medical Centre, Oslo, Norway
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42
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Fessler MB. Liver X Receptor: Crosstalk Node for the Signaling of Lipid Metabolism, Carbohydrate Metabolism, and Innate Immunity. ACTA ACUST UNITED AC 2008; 3:75-81. [PMID: 24563635 DOI: 10.2174/157436208784223170] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Liver X Receptor-α (LXRα, also known as NR1H3) and LXRβ (NR1H2) are members of the nuclear receptor superfamily of ligand-activated transcription factors, a superfamily which includes the more widely known glucocorticoid receptor, estrogen receptor, thyroid receptor, and peroxisome proliferator-activated receptors. The LXRs are activated by physiologic sterol ligands (e.g., oxysterols) and by synthetic agonists. In recent years, our understanding of the importance of LXRs has expanded across several fields of (patho-)physiology. Perhaps best known from a sizeable literature as homeostatic 'cholesterol sensors' that drive transcriptional programs promoting cellular cholesterol efflux, 'reverse cholesterol transport,' and bile acid synthesis, more recent roles for LXRs in glucose homeostasis, atherosclerosis, and innate immunity have also been identified. These discoveries complement an emerging literature that continues to draw surprisingly intimate connections between host metabolism and host defense. The present review will discuss the roles of LXR in the signaling of metabolism and innate immunity, and the potential for synthetic LXR agonists as novel therapeutics in dyslipidemia, atherosclerosis, disordered glucose metabolism, and inflammation.
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Affiliation(s)
- Michael B Fessler
- Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709
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43
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Ren S, Li X, Rodriguez-Agudo D, Gil G, Hylemon P, Pandak WM. Sulfated oxysterol, 25HC3S, is a potent regulator of lipid metabolism in human hepatocytes. Biochem Biophys Res Commun 2007; 360:802-8. [PMID: 17624300 PMCID: PMC2728003 DOI: 10.1016/j.bbrc.2007.06.143] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Accepted: 06/26/2007] [Indexed: 11/19/2022]
Abstract
Recently, a novel oxysterol, 5-cholesten-3beta, 25-diol 3-sulfate (25HC3S) was identified in primary rat hepatocytes following overexpression of the cholesterol transport protein, StarD1. This oxysterol was also detected in human liver nuclei. In the present study, 25HC3S was chemically synthesized. Addition of 25HC3S (6 microM) to human hepatocytes markedly inhibited cholesterol biosynthesis. Quantitative RT-PCR and Western blot analysis showed that 25HC3S markedly decreased HMG-CoA reductase mRNA and protein levels. Coincidently, 25HC3S inhibited the activation of sterol regulatory element binding proteins (SREBPs), suggesting that inhibition of cholesterol biosynthesis occurred via blocking SREBP-1 activation, and subsequently by inhibiting the expression of HMG CoA reductase. 25HC3S also decreased SREBP-1 mRNA levels and inhibited the expression of target genes encoding acetyl CoA carboxylase-1 (ACC-1) and fatty acid synthase (FAS). In contrast, 25-hydroxycholesterol increased SREBP1 and FAS mRNA levels in primary human hepatocytes. The results imply that 25HC3S is a potent regulator of SREBP mediated lipid metabolism.
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Affiliation(s)
- Shunlin Ren
- Department of Medicine, Veterans Affairs McGuire Medical Center/Virginia Commonwealth University, Richmond, VA 23249, USA.
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44
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Teunissen CE, Floris S, Sonke M, Dijkstra CD, De Vries HE, Lütjohann D. 24S-hydroxycholesterol in relation to disease manifestations of acute experimental autoimmune encephalomyelitis. J Neurosci Res 2007; 85:1499-505. [PMID: 17410599 DOI: 10.1002/jnr.21266] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Levels of the brain-specific cholesterol metabolite 24S-hydroxycholesterol are proposed as possible biomarkers for multiple sclerosis (MS). It is not yet clear for which aspect of the MS disease manifestations 24S-hydroxycholesterol is a reflection. We studied the relation of serum levels of 24S-hydroxycholesterol and other sterols to the disease characteristics of acute experimental autoimmune encephalomyelitis (EAE), an animal model for MS. Serum was analyzed for cholesterol precursors, oxysterols, and plant sterols during the course of disease development. Significantly increased levels of the cholesterol metabolites 24S-hydroxycholesterol and 27-hydroxycholesterol were observed on day 9, before the onset of clinical signs. The serum levels of these oxysterols gradually increased up to 193% and 415%, respectively, at day 17, when clinical symptoms had recovered. Total cholesterol levels were slightly but significantly decreased on day 9 and day 17 in treated animals. Serum levels of cholesterol precursors and plant sterols decreased gradually from day 11 and day 14, respectively. Immunostaining of the 24S-hydroxycholesterol-forming enzyme Cyp46 was shown in macrophage infiltrates. In vitro experiments confirmed the presence of Cyp46 in macrophages and showed a decreased expression after LPS treatment. The data indicate that changes in serum oxysterols occur early in EAE and can be formed by macrophages. These early changes indicate an important role for oxysterols in the development of EAE.
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Affiliation(s)
- C E Teunissen
- Department of Molecular Cell Biology, VU University Medical Center, Amsterdam, The Netherlands.
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45
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Fontaine C, Rigamonti E, Nohara A, Gervois P, Teissier E, Fruchart JC, Staels B, Chinetti-Gbaguidi G. Liver X receptor activation potentiates the lipopolysaccharide response in human macrophages. Circ Res 2007; 101:40-9. [PMID: 17540978 DOI: 10.1161/circresaha.106.135814] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Macrophages play a central role in host defense against pathogen microbes by recognizing bacterial components, resulting in the activation of an arsenal of anti-microbial effectors. Toll-like receptor (TLR)-4 mediates the recognition of lipopolysaccharide, a pathogen-associated molecular pattern from gram-negative bacteria. Activation of the TLR-4 signaling pathway by lipopolysaccharide increases antibacterial effects by inducing secretion of cytokines that activate an immune inflammatory response and by generating bactericidal reactive oxygen species via the NADPH oxidase system. Liver X Receptors (LXRs) are nuclear receptors controlling cholesterol homeostasis and inflammation in macrophages. In addition, LXRs are critical for macrophage survival and play a role in the innate immune response in the mouse. In this study, we investigated whether LXR activation also regulates host defense mechanisms in human macrophages. In primary human macrophages, oxidized LDL and synthetic LXR ligands increased TLR-4 gene expression. Transient transfection assays, gel shift and chromatin immunoprecipitation analysis indicated that LXRs induce human TLR-4 promoter activity by binding to a DR4-type LXR response element. LXR induction of TLR-4 mRNA was followed by an induction of TLR-4 protein expression. Moreover, although short-term pretreatment with LXR agonists significantly reduced the inflammatory response induced by lipopolysaccharide, pretreatment of macrophages for 48 hours with LXR agonists resulted in an enhanced lipopolysaccharide response. Finally, LXR activation increased reactive oxygen species generation by enhancing the expression of NADPH oxidase subunits. These data provide evidence for an immunomodulatory function of LXRs in human macrophages via mechanisms distinct from those previously identified in mouse macrophages.
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Affiliation(s)
- Coralie Fontaine
- Institut Pasteur de Lille, Département d'Athérosclérose, Lille, France
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46
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Dai X, Ou X, Hao X, Cao D, Tang Y, Hu Y, Li X, Tang C. Effect of T0901317 on Hepatic Proinflammatory Gene Expression in ApoE−/− Mice Fed a High-fat/high-cholesterol Diet. Inflammation 2007; 30:105-17. [PMID: 17516158 DOI: 10.1007/s10753-007-9026-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2007] [Accepted: 05/01/2007] [Indexed: 01/20/2023]
Abstract
OBJECTIVE In present study, we employed cDNA-based microarray technique to investigate the effect of a synthetic LXR ligand T0901317 on hepatic gene expression of proinflammatory cytokines in apolipoprotein E knockout mice fed an atherogenic diet. METHODS AND RESULTS Male 8-week-old apoE-/- mice were randomly divided into four groups, baseline group, vehicle group, prevention group and treatment group. All of the mice were fed a high-fat/high-cholesterol diet with or without LXR agonist T0901317 for 8 or 14 weeks. Gene array analysis found 17 atherosclerosis-related genes with a 2- to 8-fold difference in expression level between vehicle-treated group and T0901317-treated group. It induced mRNA expression of proinflammatory cytokine tumor necrosis factor (TNF), but inhibited gene expression of several other proinflammatory cytokines including interleukin (IL)-1alpha, IL-6, and IL-7 in the liver. C-reactive protein, TNF, matrix metalloproteinase-9, IL-1alpha, IL-6, and IL-7 were verified by real-time quantitative PCR. Next, enzyme-linked immunosorbent assay analyses showed up-regulation of TNFalpha levels and down-regulation of IL-alpha, IL-6, IL-7 levels in plasma sample. CONCLUSION The synthetic LXR agonist T0901317 has paradoxical roles in hepatic gene expression of proinflammatory cytokines in apoE-/- mice.
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Affiliation(s)
- Xiaoyan Dai
- Institute of Cardiovascular Research, Nanhua University, Hengyang, Hunan 421001, China
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47
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Mooijaart SP, Kuningas M, Westendorp RGJ, Houwing-Duistermaat JJ, Slagboom PE, Rensen PCN, van Heemst D. Liver X Receptor Alpha Associates With Human Life Span. J Gerontol A Biol Sci Med Sci 2007; 62:343-9. [PMID: 17452725 DOI: 10.1093/gerona/62.4.343] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In the nematode Caenorhabditis elegans, nuclear hormone receptor DAF-12 regulates the decision to go into a resistant dauer diapause, in which the worm exhibits a decreased rate of aging. Using sequence similarity searches, we previously identified the liver X receptor alpha (LXRalpha) as one of the human nuclear hormone receptors the protein sequence of which is most similar to C. elegans DAF-12. Here, we studied whether variation in the gene encoding LXRalpha associates with human life span. In the Leiden 85-Plus Study, a population-based prospective follow-up study, we genotyped four polymorphisms spanning the gene coding for LXRalpha (NR1H3) and tagged four common haplotypes. Among 563 participants, haplotype 2 associated with reduced mortality during the 7-year follow-up (hazard ratio 0.78; p =.015), predominantly caused by reduced mortality from infectious disease (hazard ratio 0.31; p =.023). Haplotype 2 also associated with higher levels of plasma apolipoprotein E, a target gene of the LXRalpha (p =.018), and higher levels of triglycerides (p =.041). Genetic variation in the gene coding for the LXRalpha (NR1H3) associates with human life span.
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Affiliation(s)
- Simon P Mooijaart
- Department of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, The Netherlands.
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48
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Kang MA, Jeoung NH, Kim JY, Lee JE, Jung UJ, Choi MS, Lee WH, Kwon OS, Lee H, Park YB. Up-regulation of skeletal muscle LIM protein 1 gene by 25-hydroxycholesterol may mediate morphological changes of rat aortic smooth muscle cells. Life Sci 2007; 80:460-7. [PMID: 17161435 DOI: 10.1016/j.lfs.2006.09.036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2006] [Revised: 07/26/2006] [Accepted: 09/27/2006] [Indexed: 11/22/2022]
Abstract
Changes in the expression level of the skeletal muscle LIM protein 1 (SLIM1) in cultured A10 cells were monitored in response to 25-hydroxycholesterol (25-HC), an oxidized form of cholesterol present in the oxidized low-density lipoproteins. The level of SLIM1 mRNA was elevated in a time- and concentration-dependent manner by treatment of 25-HC. Expressions of smooth muscle (SM) alpha-actin and calponin-1 (CNN-1), early markers for SMC differentiation, were also increased by the 25-HC treatments. Expressions of all three genes (SLIM1, SM alpha-actin and CNN-1) were simultaneously elevated in the cells treated with 9-cis retinoic acid (RA). On the other hand, the SLIM1 expression induced by the 25-HC or 9-cis RA (as well as SM alpha-actin and CNN-1) was decreased by the treatment of 15d-PGJ2. Since the 25-HC, 9-cis RA and 15d-PGJ2 were ligands for the LXR, RXRalpha and PPARgamma respectively, there might be a functional positive cross-talk between LXR and RXRalpha pathways and a negative cross-talk between PPARgamma and LXR and/or RXRalpha pathways in the regulation of SLIM1 expression. The cells stably transfected with the expressional vector for SLIM1 also showed an elevation in the levels of SM alpha-actin and CNN-1. In addition, an over-production of SLIM1 in the cells resulted in a change in the cell-shape into a spindle-like form, which is identical to that observed after a prolonged treatment of the cells with cholesterol.
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MESH Headings
- Actins/genetics
- Alitretinoin
- Animals
- Aorta/cytology
- Aorta/drug effects
- Aorta/metabolism
- Calcium-Binding Proteins/genetics
- Cell Differentiation/drug effects
- Cell Line
- Cell Shape/drug effects
- Cell Shape/genetics
- Dose-Response Relationship, Drug
- Gene Expression Regulation/drug effects
- Hydroxycholesterols/pharmacology
- LIM Domain Proteins
- Microfilament Proteins/genetics
- Muscle Proteins/genetics
- Muscle, Skeletal/cytology
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Prostaglandin D2/analogs & derivatives
- Prostaglandin D2/pharmacology
- Rats
- Time Factors
- Tretinoin/pharmacology
- Up-Regulation
- Calponins
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Affiliation(s)
- Mi Ae Kang
- Department of Genetic Engineering, Kyungpook National University, 702-701, Republic of Korea
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49
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Calleros L, Lasa M, Toro MJ, Chiloeches A. Low cell cholesterol levels increase NFkappaB activity through a p38 MAPK-dependent mechanism. Cell Signal 2006; 18:2292-301. [PMID: 16806824 DOI: 10.1016/j.cellsig.2006.05.012] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2006] [Revised: 05/16/2006] [Accepted: 05/17/2006] [Indexed: 02/05/2023]
Abstract
Cholesterol, p38 MAPK and NFkappaB have been shown to participate in inflammation and cellular differentiation. Here, we examined the effect of cholesterol on NFkappaB-dependent transcription and the mechanisms underlying this effect in NIH3T3 cells. We show that chronic cholesterol depletion achieved with lipoprotein-deficient serum (LPDS) and 25-hydroxycholesterol (25-HC) treatment resulted in a significant increase in NFkappaB-dependent transcription, NFkappaB-DNA binding, IkappaBalpha degradation and p65/NFkappaB translocation to the nucleus, and the addition of exogenous cholesterol reversed these effects. Previously, we have shown that low cell cholesterol levels activate p38 MAPK. Here, we found that inhibition of p38 MAPK with the specific inhibitor SB203580 blocked the increase in NFkappaB activity, IkappaBalpha degradation and p65/NFkappaB translocation to the nucleus induced by cholesterol depletion. Moreover, the inhibition of the p38 MAPK downstream effector MSK1 with the specific inhibitor H89, or the overexpression of a kinase defective MSK1 abrogated the NFkappaB-dependent transcription induced by cholesterol depletion. On the other hand, the transactivation potential of p65/NFkappaB depends on phosphorylation of S276 by MSK1. We observed that cholesterol depletion increased the p65/NFkappaB transactivation capacity. This effect was reversed by cell cholesterol repletion or incubation with the SB203580 inhibitor. Moreover, the expression of a p65/NFkappaB S276A mutant was insensitive to cholesterol depletion. Together, our results demonstrate that cholesterol depletion induces NFkappaB transcriptional activity, not only by affecting the IkappaBalpha degradation and the translocation of p65/NFkappaB to the nucleus, but also regulating the p65/NFkappaB transactivating potential through a p38 MAPK/MSK1 mediated pathway.
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Affiliation(s)
- Laura Calleros
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain
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50
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Takeuchi C, Galvé R, Nieva J, Witter DP, Wentworth AD, Troseth RP, Lerner RA, Wentworth P. Proatherogenic Effects of the Cholesterol Ozonolysis Products, Atheronal-A and Atheronal-B†. Biochemistry 2006; 45:7162-70. [PMID: 16752907 DOI: 10.1021/bi0604330] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The proatherogenic properties of the cholesterol 5,6-secosterols (atheronal-A and atheronal-B), recently discovered in atherosclerotic arteries, have been investigated in terms of their effects on monocyte/macrophage function. A fluorescent analogue of atheronal-B (1) (50 microM), when cultured in either aqueous buffer (PBS) or in media containing fetal calf serum (10%), is rapidly taken-up into cultured macrophage (J774.1 or RAW 264.7) cells and accumulates at perinuclear sites (within 1 h). Co-incubation of macrophage cells (J774.1) with atheronal-A (25 microM) and atheronal-B (25 microM) when complexed with low-density lipoprotein (LDL) (100 microg/mL) leads to a significant upregulation of scavenger receptor class A (approximately 3-fold increase relative to LDL alone, p < 0.05) but not CD36, showing that cultured macrophages respond to LDL-complexed atheronals in a manner highly analogous to acetylated LDL rather than oxidized LDL. Both atheronal-A and atheronal-B in solution exhibit a dose-dependent (0-25 microM) induction of chemotaxis of cultured macrophages (p < 0.001). When complexed with LDL (100 microg/mL), atheronal-A (but not atheronal-B) induces a dose-dependent (0-25 microM, p < 0.05) upregulation of the cell-surface adhesion molecule endothelial (E)-selectin on vascular endothelial cells (HUVECs). LDL (100 microg/mL) complexed atheronal-B (25 microM) but not atheronal-A induces cultured human monocytes (THP-1) to differentiate into macrophage cell lineage. When these in vitro data are taken together with the already known effects of cholesterol 5,6-secosterols on foam cell formation and macrophage cytotoxicity, the atheronals possess biological effects that if translated to an in vivo setting could lead to the recruitment, entrapment, dysfunction, and ultimate destruction of macrophages, with the major leukocyte player in inflammatory artery disease. As such, the atheronal molecules may be a new association, in the already complex inter-relationship, between inflammation, cholesterol oxidation, the tissue macrophage, and atherosclerosis.
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Affiliation(s)
- Cindy Takeuchi
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
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