1
|
Wang J, Liu YM, Hu J, Chen C. Trained immunity in monocyte/macrophage: Novel mechanism of phytochemicals in the treatment of atherosclerotic cardiovascular disease. Front Pharmacol 2023; 14:1109576. [PMID: 36895942 PMCID: PMC9989041 DOI: 10.3389/fphar.2023.1109576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 01/27/2023] [Indexed: 02/23/2023] Open
Abstract
Atherosclerosis (AS) is the pathology of atherosclerotic cardiovascular diseases (ASCVD), characterized by persistent chronic inflammation in the vessel wall, in which monocytes/macrophages play a key role. It has been reported that innate immune system cells can assume a persistent proinflammatory state after short stimulation with endogenous atherogenic stimuli. The pathogenesis of AS can be influenced by this persistent hyperactivation of the innate immune system, which is termed trained immunity. Trained immunity has also been implicated as a key pathological mechanism, leading to persistent chronic inflammation in AS. Trained immunity is mediated via epigenetic and metabolic reprogramming and occurs in mature innate immune cells and their bone marrow progenitors. Natural products are promising candidates for novel pharmacological agents that can be used to prevent or treat cardiovascular diseases (CVD). A variety of natural products and agents exhibiting antiatherosclerotic abilities have been reported to potentially interfere with the pharmacological targets of trained immunity. This review describes in as much detail as possible the mechanisms involved in trained immunity and how phytochemicals of this process inhibit AS by affecting trained monocytes/macrophages.
Collapse
Affiliation(s)
- Jie Wang
- Guang'anmen Hospital, China Academy of Chinese Medicine Sciences, Beijing, China
| | - Yong-Mei Liu
- Guang'anmen Hospital, China Academy of Chinese Medicine Sciences, Beijing, China
| | - Jun Hu
- Guang'anmen Hospital, China Academy of Chinese Medicine Sciences, Beijing, China
| | - Cong Chen
- Guang'anmen Hospital, China Academy of Chinese Medicine Sciences, Beijing, China
| |
Collapse
|
2
|
Huwait EA, Saddeek SY, Al-Massabi RF, Almowallad SJ, Pushparaj PN, Kalamegam G. Antiatherogenic Effects of Quercetin in the THP-1 Macrophage Model In Vitro, With Insights Into Its Signaling Mechanisms Using In Silico Analysis. Front Pharmacol 2021; 12:698138. [PMID: 34385920 PMCID: PMC8353397 DOI: 10.3389/fphar.2021.698138] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 06/25/2021] [Indexed: 01/08/2023] Open
Abstract
Background: Atherosclerosis (AS), a major risk factor for stroke and brain tissue destruction, is an inflammatory disease of the blood vessels, and the underlying pathology is inflammation mediated by various chemokines and cytokines. Quercetin, a natural flavonol, is reported to have both anti-inflammatory and antioxidant properties. As such, in the present study, we evaluated the antiatherogenic effects of quercetin in a human THP-1 cell line in vitro and also the signaling mechanisms using in silico analysis. Materials and Methods: THP-1 macrophages exposed to different concentrations of quercetin (5–100 μM for 24 h) were tested for cytotoxicity. Real-time gene expression assay for intercellular adhesion molecule-1 (ICAM-1) and monocyte chemoattractant protein-1 (MCP-1) was carried out following treatment with quercetin at 15 and 30 μM for 24 h either in the absence or presence of interferon (IFN-γ) for 3 h to induce inflammation. Monocyte migration and cholesterol efflux were also assessed. Results: Quercetin did not exert any cytotoxic effects on THP-1 cells at the various concentrations tested. The gene expression assay showed a significant decrease in ICAM-1 (by 3.05 and 2.70) and MCP-1 (by 22.71 and 27.03), respectively. Quercetin at 15 µM decreased THP-1 monocyte migration by 33% compared to the MCP-1-treated cells. It also increased cholesterol efflux significantly by1.64-fold and 1.60-fold either alone or in combination with IFN-γ, respectively. Ingenuity Pathway Analysis of the molecular interactions of quercetin identified canonical pathways directly related to lipid uptake and cholesterol efflux. Furthermore, CD36, SR-A, and LXR-α also demonstrated significant increases by 72.16-, 149.10-, and 29.68-fold, respectively. Conclusion: Our results from both in vitro and in silico studies identified that quercetin inhibited the THP-1 monocyte migration, MCP-1, and ICAM-1 and increased cholesterol efflux probably mediated via the LXR/RXR signaling pathway. Therefore, quercetin will help prevent cell infiltration in atherosclerotic plaques and reduce the risk of stroke or brain destruction.
Collapse
Affiliation(s)
- Etimad A Huwait
- Biochemistry Department, Faculty of Sciences, King Abdulaziz University, Jeddah, Saudi Arabia.,Cell Culture Unit and Experimental Biochemistry Unit, King Fahad Medical Research Centre, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Salma Y Saddeek
- Biochemistry Department, Faculty of Sciences, King Abdulaziz University, Jeddah, Saudi Arabia.,Cell Culture Unit and Experimental Biochemistry Unit, King Fahad Medical Research Centre, King Abdulaziz University, Jeddah, Saudi Arabia.,Chemistry Department, Faculty of Sciences, University of Hafr Al Batin, Hafr Al Batin, Saudi Arabia
| | - Rehab F Al-Massabi
- Biochemistry Department, Faculty of Sciences, King Abdulaziz University, Jeddah, Saudi Arabia.,Cell Culture Unit and Experimental Biochemistry Unit, King Fahad Medical Research Centre, King Abdulaziz University, Jeddah, Saudi Arabia.,Biochemistry Department, Faculty of Sciences, University of Tabuk, Tabuk, Saudi Arabia
| | - Sanaa J Almowallad
- Biochemistry Department, Faculty of Sciences, King Abdulaziz University, Jeddah, Saudi Arabia.,Cell Culture Unit and Experimental Biochemistry Unit, King Fahad Medical Research Centre, King Abdulaziz University, Jeddah, Saudi Arabia.,Biochemistry Department, Faculty of Sciences, University of Tabuk, Tabuk, Saudi Arabia
| | - Peter Natesan Pushparaj
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, Jeddah, Saudi Arabia.,Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Gauthaman Kalamegam
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, Jeddah, Saudi Arabia.,Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia.,Pharmaceutical Division, Nibblen Life Sciences Private Limited, Chennai, India
| |
Collapse
|
3
|
Liver X Receptor Expression and Pentraxin 3 Production in Chronic Rhinosinusitis and Sinonasal Mucosal Fibroblast Cells. J Clin Med 2021; 10:jcm10030452. [PMID: 33503887 PMCID: PMC7865759 DOI: 10.3390/jcm10030452] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 01/16/2021] [Accepted: 01/19/2021] [Indexed: 12/15/2022] Open
Abstract
The long pentraxin 3 (PTX3) is a prototypic molecule for recognizing pathogens. Liver X receptors (LXRs), belonging to nuclear receptors (NRs) for cholesterol metabolism through heterodimerizing with other NRs, were recently reported to participate in inflammation. However, their roles in chronic rhinosinusitis without nasal polyps (CRSsNP) are unclear. Therefore, this study was sought to explore roles of LXRs in chronic rhinosinusitis (CRS) sinonasal tissues and derived fibroblasts. Immunohistochemistry indicated that LXRα and β expression and lipid/fat deposition were differentially expressed in the control and CRSsNP nasal mucosa. GW7647 (a peroxisome proliferator activated receptor α (PPARα) agonist) and GW3965 (a dual agonist for LXRα and β) significantly caused PTX3 induction in the fibroblast cells. GW3965 induced PTX3 mRNA and protein expression, and the induction substantially led to PTX3 secretion. Meanwhile, an endogenous agonist-cholesterol had a similar enhancing effect on the induction of PTX3 protein. LXR siRNA knockdown to lower LXRα or β expression significantly compromised PTX3 induction. Interestingly, GW3965 also induced phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) activation and its inhibition reduced PTX3 expression. Collectively, we demonstrated here for the first time that CRSsNP nasal mucosa differentially expresses LXRα and β and deposits lipids/fats that may contain cholesterol metabolites to activate LXRs. Activation of LXRs leads to PTX3 production in sinonasal mucosa-derived fibroblasts. Our previous study showed PTX3 overexpression in the nasal cavity of CRSsNP, whereas this study highlights that cholesterol metabolites and LXR activation regulate PTX3 production and may contribute to antimicrobial activity and tissue repair during CRSsNP progression.
Collapse
|
4
|
Wang D, Yang Y, Lei Y, Tzvetkov NT, Liu X, Yeung AWK, Xu S, Atanasov AG. Targeting Foam Cell Formation in Atherosclerosis: Therapeutic Potential of Natural Products. Pharmacol Rev 2019; 71:596-670. [PMID: 31554644 DOI: 10.1124/pr.118.017178] [Citation(s) in RCA: 114] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Foam cell formation and further accumulation in the subendothelial space of the vascular wall is a hallmark of atherosclerotic lesions. Targeting foam cell formation in the atherosclerotic lesions can be a promising approach to treat and prevent atherosclerosis. The formation of foam cells is determined by the balanced effects of three major interrelated biologic processes, including lipid uptake, cholesterol esterification, and cholesterol efflux. Natural products are a promising source for new lead structures. Multiple natural products and pharmaceutical agents can inhibit foam cell formation and thus exhibit antiatherosclerotic capacity by suppressing lipid uptake, cholesterol esterification, and/or promoting cholesterol ester hydrolysis and cholesterol efflux. This review summarizes recent findings on these three biologic processes and natural products with demonstrated potential to target such processes. Discussed also are potential future directions for studying the mechanisms of foam cell formation and the development of foam cell-targeted therapeutic strategies.
Collapse
Affiliation(s)
- Dongdong Wang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
| | - Yang Yang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
| | - Yingnan Lei
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
| | - Nikolay T Tzvetkov
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
| | - Xingde Liu
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
| | - Andy Wai Kan Yeung
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
| | - Suowen Xu
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
| | - Atanas G Atanasov
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
| |
Collapse
|
5
|
Coates HW, Chua NK, Brown AJ. Consulting prostate cancer cohort data uncovers transcriptional control: Regulation of the MARCH6 gene. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:1656-1668. [PMID: 31422115 DOI: 10.1016/j.bbalip.2019.08.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 08/01/2019] [Accepted: 08/14/2019] [Indexed: 12/28/2022]
Abstract
Cholesterol accumulation is a hallmark of prostate cancer (PCa) enabled by the upregulation of its synthesis, which presents a potential therapeutic target. This pathway is suppressed by the E3 ubiquitin ligase membrane-associated RING-CH-type finger 6 (MARCH6); however, little is known of MARCH6 regulation, particularly at the transcriptional level. Here, we consulted large transcriptomic PCa datasets to investigate transcription factors and DNA sequence elements that regulate the MARCH6 gene. Amongst 498 primary PCa tissues of The Cancer Genome Atlas, we identified a striking positive correlation between MARCH6 and androgen receptor (AR) gene expression (r = 0.81, p < 1 × 10-117) that held in other primary tumour datasets. Two putative androgen response elements were identified in the MARCH6 gene using motif prediction and mining of publicly accessible chromatin immunoprecipitation-sequencing data. However, MARCH6 expression was not androgen-responsive in luciferase reporter and qRT-PCR assays. Instead, we established that the MARCH6-AR correlation in primary PCa is due to common regulation by the transcription factor Sp1. We located a region 100 bp downstream of the MARCH6 transcriptional start site that contains three Sp1 binding sites and strongly upregulates promoter activity. The functionality of this region, and Sp1-mediated upregulation of MARCH6, was confirmed using pharmacological and genetic inhibition of Sp1. Moreover, modulation of Sp1 activity affected the stability of squalene monooxygenase, a cholesterol biosynthesis enzyme and MARCH6 substrate. We thus establish Sp1 as the first known regulator of the MARCH6 gene and demonstrate that interrogation of transcriptomic datasets can assist in the de novo inference of transcriptional regulation.
Collapse
Affiliation(s)
- Hudson W Coates
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia
| | - Ngee Kiat Chua
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia
| | - Andrew J Brown
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia.
| |
Collapse
|
6
|
Rigalli JP, Tocchetti GN, Weiss J. Modulation of ABC Transporters by Nuclear Receptors: Physiological, Pathological and Pharmacological Aspects. Curr Med Chem 2019; 26:1079-1112. [DOI: 10.2174/0929867324666170920141707] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 07/24/2017] [Accepted: 08/08/2017] [Indexed: 12/11/2022]
Abstract
ABC transporters are membrane proteins mediating the efflux of endo- and xenobiotics. Transporter expression is not static but instead is subject to a dynamic modulation aiming at responding to changes in the internal environment and thus at maintaining homeostatic conditions. Nuclear receptors are ligand modulated transcription factors that get activated upon changes in the intracellular concentrations of the respective agonists and bind to response elements within the promoter of ABC transporters, thus modulating their expression and, consequently, their activity. This review compiles information about transporter regulation by nuclear receptors classified according to the perpetrator compounds and the biological effects resulting from the regulation. Modulation by hormone receptors is involved in maintaining endocrine homeostasis and may also lead to an altered efflux of other substrates in cases of altered hormonal levels. Xenobiotic receptors play a key role in limiting the accumulation of potentially harmful compounds. In addition, their frequent activation by therapeutic agents makes them common molecular elements mediating drug-drug interactions and cancer multidrug resistance. Finally, lipid and retinoid receptors are usually activated by endogenous molecules, thus sensing metabolic changes and inducing ABC transporters to counteract potential alterations. Furthermore, the axis nuclear receptor-ABC transporter constitutes a promising therapeutic target for the treatment of several disease states like cancer, atherosclerosis and dyslipidemia. In the current work, we summarize the information available on the pharmacological potential of nuclear receptor modulators and discuss their applicability in the clinical practice.
Collapse
Affiliation(s)
- Juan Pablo Rigalli
- Department of Clinical Pharmacology and Pharmacoepidemiology. University of Heidelberg. Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Guillermo Nicolás Tocchetti
- Department of Clinical Pharmacology and Pharmacoepidemiology. University of Heidelberg. Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Johanna Weiss
- Department of Clinical Pharmacology and Pharmacoepidemiology. University of Heidelberg. Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| |
Collapse
|
7
|
Sáenz J, Alba G, Reyes-Quiroz ME, Geniz I, Jiménez J, Sobrino F, Santa-María C. Curcumin enhances LXRα in an AMP-activated protein kinase-dependent manner in human macrophages. J Nutr Biochem 2018; 54:48-56. [DOI: 10.1016/j.jnutbio.2017.11.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 09/11/2017] [Accepted: 11/11/2017] [Indexed: 12/19/2022]
|
8
|
Huwait EA, Singh NN, Michael DR, Davies TS, Moss JW, Ramji DP. Protein Kinase C Is Involved in the Induction of ATP-Binding Cassette Transporter A1 Expression by Liver X Receptor/Retinoid X Receptor Agonist in Human Macrophages. J Cell Biochem 2015; 116:2032-8. [DOI: 10.1002/jcb.25157] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 03/03/2015] [Indexed: 11/12/2022]
Affiliation(s)
- Etimad A. Huwait
- Cardiff School of Biosciences; Cardiff University; Sir Martin Evans Building Museum Avenue Cardiff CF10 3AX United Kingdom
| | - Nishi N. Singh
- Cardiff School of Biosciences; Cardiff University; Sir Martin Evans Building Museum Avenue Cardiff CF10 3AX United Kingdom
| | - Daryn R. Michael
- Cardiff School of Biosciences; Cardiff University; Sir Martin Evans Building Museum Avenue Cardiff CF10 3AX United Kingdom
| | - Thomas S. Davies
- Cardiff School of Biosciences; Cardiff University; Sir Martin Evans Building Museum Avenue Cardiff CF10 3AX United Kingdom
| | - Joe W.E. Moss
- Cardiff School of Biosciences; Cardiff University; Sir Martin Evans Building Museum Avenue Cardiff CF10 3AX United Kingdom
| | - Dipak P. Ramji
- Cardiff School of Biosciences; Cardiff University; Sir Martin Evans Building Museum Avenue Cardiff CF10 3AX United Kingdom
| |
Collapse
|
9
|
Kardassis D, Gafencu A, Zannis VI, Davalos A. Regulation of HDL genes: transcriptional, posttranscriptional, and posttranslational. Handb Exp Pharmacol 2015; 224:113-179. [PMID: 25522987 DOI: 10.1007/978-3-319-09665-0_3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
HDL regulation is exerted at multiple levels including regulation at the level of transcription initiation by transcription factors and signal transduction cascades; regulation at the posttranscriptional level by microRNAs and other noncoding RNAs which bind to the coding or noncoding regions of HDL genes regulating mRNA stability and translation; as well as regulation at the posttranslational level by protein modifications, intracellular trafficking, and degradation. The above mechanisms have drastic effects on several HDL-mediated processes including HDL biogenesis, remodeling, cholesterol efflux and uptake, as well as atheroprotective functions on the cells of the arterial wall. The emphasis is on mechanisms that operate in physiologically relevant tissues such as the liver (which accounts for 80% of the total HDL-C levels in the plasma), the macrophages, the adrenals, and the endothelium. Transcription factors that have a significant impact on HDL regulation such as hormone nuclear receptors and hepatocyte nuclear factors are extensively discussed both in terms of gene promoter recognition and regulation but also in terms of their impact on plasma HDL levels as was revealed by knockout studies. Understanding the different modes of regulation of this complex lipoprotein may provide useful insights for the development of novel HDL-raising therapies that could be used to fight against atherosclerosis which is the underlying cause of coronary heart disease.
Collapse
Affiliation(s)
- Dimitris Kardassis
- Department of Biochemistry, University of Crete Medical School and Institute of Molecular Biology and Biotechnology, Foundation of Research and Technology of Hellas, Heraklion, Crete, 71110, Greece,
| | | | | | | |
Collapse
|
10
|
He F, Han C, Liu D, Wan H, Wang J, Liu H, Li L, Xu H, He H. Effect of a Synthetic Liver X Receptor Agonist TO901317 on Cholesterol Concentration in Goose Primary Hepatocytes. ITALIAN JOURNAL OF ANIMAL SCIENCE 2014. [DOI: 10.4081/ijas.2014.2979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
11
|
Wang SF, Chou YC, Mazumder N, Kao FJ, Nagy LD, Guengerich FP, Huang C, Lee HC, Lai PS, Ueng YF. 7-Ketocholesterol induces P-glycoprotein through PI3K/mTOR signaling in hepatoma cells. Biochem Pharmacol 2013; 86:548-60. [PMID: 23792120 PMCID: PMC4164904 DOI: 10.1016/j.bcp.2013.06.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 06/10/2013] [Accepted: 06/10/2013] [Indexed: 12/30/2022]
Abstract
7-Ketocholesterol (7-KC) is found at an elevated level in patients with cancer and chronic liver disease. The up-regulation of an efflux pump, P-glycoprotein (P-gp) leads to drug resistance. To elucidate the effect of 7-KC on P-gp, P-gp function and expression were investigated in hepatoma cell lines Huh-7 and HepG2 and in primary hepatocyte-derived HuS-E/2 cells. At a subtoxic concentration, 48-h exposure to 7-KC reduced the intracellular accumulation and cytotoxicity of P-gp substrate doxorubicin in hepatoma cells, but not in HuS-E/2 cells. In Huh-7 cells, 7-KC elevated efflux function through the activation of phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) pathway. 7-KC activated the downstream protein synthesis initiation factor 4E-BP1 and induced P-gp expression post-transcriptionally. The stimulation of efflux was reversible and could not be prevented by N-acetyl cysteine. Total cellular ATP content remained the same, whereas the lactate production was increased and fluorescence lifetime of protein-bound NADH was shortened. These changes suggested a metabolic shift to glycolysis, but glycolytic inhibitors did not eliminate 7-KC-mediated P-gp induction. These results demonstrate that 7-KC induces P-gp through PI3K/mTOR signaling and decreased the cell-killing efficacy of doxorubicin in hepatoma cells.
Collapse
Affiliation(s)
- Sheng-Fan Wang
- National Research Institute of Chinese Medicine, No. 155-1, Li-Nong Street, Sec. 2, Taipei 112, Taiwan, ROC
- Department and Institute of Pharmacology, School of Medicine, National Yang-Ming University, No. 155, Li-Nong Street, Sec. 2,Taipei 112, Taiwan, ROC
- Department of Pharmacy, Taipei Veterans General Hospital, No. 201, Sec. 2, Shih-Pai Road, Taipei 112, Taiwan, ROC
| | - Yueh-Ching Chou
- Department and Institute of Pharmacology, School of Medicine, National Yang-Ming University, No. 155, Li-Nong Street, Sec. 2,Taipei 112, Taiwan, ROC
- Department of Pharmacy, Taipei Veterans General Hospital, No. 201, Sec. 2, Shih-Pai Road, Taipei 112, Taiwan, ROC
- Department of Pharmacy, Taipei Medical University, No. 250, Wuxing Street, Taipei 110, Taiwan, ROC
| | - Nirmal Mazumder
- Institute of Biophotonics, School of Biomedical Science and Engineering, National Yang-Ming University, No. 155, Li-Nong Street, Sec. 2, Taipei 112, Taiwan, ROC
| | - Fu-Jen Kao
- Institute of Biophotonics, School of Biomedical Science and Engineering, National Yang-Ming University, No. 155, Li-Nong Street, Sec. 2, Taipei 112, Taiwan, ROC
| | - Leslie D. Nagy
- Department of Biochemistry and Center in Molecular Toxicology, Vanderbilt University, School of Medicine, Nashville, TN 37232-0146, USA
| | - F. Peter Guengerich
- Department of Biochemistry and Center in Molecular Toxicology, Vanderbilt University, School of Medicine, Nashville, TN 37232-0146, USA
| | - Cheng Huang
- National Research Institute of Chinese Medicine, No. 155-1, Li-Nong Street, Sec. 2, Taipei 112, Taiwan, ROC
| | - Hsin-Chen Lee
- Department and Institute of Pharmacology, School of Medicine, National Yang-Ming University, No. 155, Li-Nong Street, Sec. 2,Taipei 112, Taiwan, ROC
| | - Ping-Shan Lai
- Department of Chemistry, College of Science, National Chung Hsin University, 250 Kuo Kuang Rd., Taichung 402, Taiwan, ROC
| | - Yune-Fang Ueng
- National Research Institute of Chinese Medicine, No. 155-1, Li-Nong Street, Sec. 2, Taipei 112, Taiwan, ROC
- Department and Institute of Pharmacology, School of Medicine, National Yang-Ming University, No. 155, Li-Nong Street, Sec. 2,Taipei 112, Taiwan, ROC
- Institute of Medical Sciences, Taipei Medical University, No. 250, Wuxing Street, Taipei 110, Taiwan, ROC
| |
Collapse
|
12
|
Yan JQ, Tan CZ, Wu JH, Zhang DC, Chen JL, Zeng BY, Jiang YP, Nie J, Liu W, Liu Q, Dai H. Neopterin negatively regulates expression of ABCA1 and ABCG1 by the LXRα signaling pathway in THP-1 macrophage-derived foam cells. Mol Cell Biochem 2013; 379:123-31. [PMID: 23564066 DOI: 10.1007/s11010-013-1634-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Accepted: 03/27/2013] [Indexed: 12/15/2022]
Abstract
To investigate the effects of neopterin on ABCA1 expression and cholesterol efflux in human THP-1 macrophage-derived foam cells, and to explore the role of the liver X receptor alpha (LXRα) involved. In the present study, THP-1 cells were pre-incubated with ox-LDL to become foam cells. The protein and mRNA expression were examined by Western blot assays and real-time quantitative PCR, respectively. Liquid scintillation counting and high performance liquid chromatography assays were used to test cellular cholesterol efflux and cholesterol content. Neopterin decreased ABCA1 expression and cholesterol efflux in a time- and concentration-dependent manner in THP-1 macrophage-derived foam cells, and the LXRα siRNA can reverse the inhibitory effects induced by neopterin. Neoterin has a negative regulation on ABCA1 expression via the LXRα signaling pathway, which suggests the aggravated effects of neopterin on atherosclerosis.
Collapse
Affiliation(s)
- Jin-quan Yan
- Affiliated Hospital of Shaoyang Medical College, Shaoyang, Hunan, China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Foster JG, Blunt MD, Carter E, Ward SG. Inhibition of PI3K signaling spurs new therapeutic opportunities in inflammatory/autoimmune diseases and hematological malignancies. Pharmacol Rev 2013; 64:1027-54. [PMID: 23023033 DOI: 10.1124/pr.110.004051] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The phosphoinositide 3-kinase/mammalian target of rapamycin/protein kinase B (PI3K/mTOR/Akt) signaling pathway is central to a plethora of cellular mechanisms in a wide variety of cells including leukocytes. Perturbation of this signaling cascade is implicated in inflammatory and autoimmune disorders as well as hematological malignancies. Proteins within the PI3K/mTOR/Akt pathway therefore represent attractive targets for therapeutic intervention. There has been a remarkable evolution of PI3K inhibitors in the past 20 years from the early chemical tool compounds to drugs that are showing promise as anticancer agents in clinical trials. The use of animal models and pharmacological tools has expanded our knowledge about the contribution of individual class I PI3K isoforms to immune cell function. In addition, class II and III PI3K isoforms are emerging as nonredundant regulators of immune cell signaling revealing potentially novel targets for disease treatment. Further complexity is added to the PI3K/mTOR/Akt pathway by a number of novel signaling inputs and feedback mechanisms. These can present either caveats or opportunities for novel drug targets. Here, we consider recent advances in 1) our understanding of the contribution of individual PI3K isoforms to immune cell function and their relevance to inflammatory/autoimmune diseases as well as lymphoma and 2) development of small molecules with which to inhibit the PI3K pathway. We also consider whether manipulating other proximal elements of the PI3K signaling cascade (such as class II and III PI3Ks or lipid phosphatases) are likely to be successful in fighting off different immune diseases.
Collapse
Affiliation(s)
- John G Foster
- Inflammatory Cell Biology Laboratory, Department of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath, UK.
| | | | | | | |
Collapse
|
14
|
Abstract
Liver X receptors (LXRs) belong to the nuclear receptor superfamily of ligand-dependent transcription factors. LXRs are activated by oxysterols, metabolites of cholesterol, and therefore act as intracellular sensors of this lipid. There are two LXR genes (α and β) that display distinct tissue/cell expression profiles. LXRs interact with regulatory sequences in target genes as heterodimers with retinoid X receptor. Such direct targets of LXR actions include important genes implicated in the control of lipid homeostasis, particularly reverse cholesterol transport. In addition, LXRs attenuate the transcription of genes associated with the inflammatory response indirectly by transrepression. In this review, we describe recent evidence that both highlights the key roles of LXRs in atherosclerosis and inflammation and provides novel insights into the mechanisms underlying their actions. In addition, we discuss the major limitations of LXRs as therapeutic targets for the treatment of atherosclerosis and how these are being addressed.
Collapse
|
15
|
de Nigris F, Rienzo M, Sessa M, Infante T, Cesario E, Ignarro LJ, Al-Omran M, Giordano A, Palinski W, Napoli C. Glycoxydation promotes vascular damage via MAPK-ERK/JNK pathways. J Cell Physiol 2012; 227:3639-47. [PMID: 22331607 DOI: 10.1002/jcp.24070] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Oxidation and glycation enhance foam cell formation via MAPK/JNK in euglycemic and diabetic subjects. Here, we investigated the effects of glycated and oxidized LDL (glc-oxLDL) on MAPK-ERK and JNK signaling pathways using human coronary smooth muscle cells. Glc-oxLDL induced a broad cascade of MAPK/JNK-dependent signaling transduction pathways and the AP-1 complex. In glc-oxLDL treated coronary arterioles, tumor necrosis factor (TNF) α increased JNK phosphorylation, whereas protein kinase inhibitor dimethylaminopurine (DMAP) prevented the TNF-induced increase in JNK phosphorylation. The role of MKK4 and JNK were then investigated in vivo, using apolipoprotein E knockout (ApoE(-/-)) mice. Peritoneal macrophages, isolated from spontaneously hyperlipidemic but euglycemic mice showed increases in both proteins and phosphorylated proteins. Compared to streptozotocin-treated diabetic C57BL6 and nondiabetic C57BL6 Wt mice, in streptozotocin-diabetic ApoE(-/-) mice, the increment of foam cell formation corresponded to an increment of phosphorylation of JNK1, JNK2, and MMK4. Thus, we provide a first line of evidence that MAPK-ERK/JNK pathways are involved in vascular damage induced by glycoxidation.
Collapse
Affiliation(s)
- Filomena de Nigris
- Department of General Pathology, U.O.C. Immunohematology, and Excellence Research Centre on Cardiovascular Disease, 1st School of Medicine, Second University of Naples, Naples, Italy
| | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Kang J, Rivest S. Lipid metabolism and neuroinflammation in Alzheimer's disease: a role for liver X receptors. Endocr Rev 2012; 33:715-46. [PMID: 22766509 DOI: 10.1210/er.2011-1049] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Liver X receptors (LXR) are nuclear receptors that have emerged as key regulators of lipid metabolism. In addition to their functions as cholesterol sensors, LXR have also been found to regulate inflammatory responses in macrophages. Alzheimer's disease (AD) is a neurodegenerative disease characterized by a progressive cognitive decline associated with inflammation. Evidence indicates that the initiation and progression of AD is linked to aberrant cholesterol metabolism and inflammation. Activation of LXR can regulate neuroinflammation and decrease amyloid-β peptide accumulation. Here, we highlight the role of LXR in orchestrating lipid homeostasis and neuroinflammation in the brain. In addition, diabetes mellitus is also briefly discussed as a significant risk factor for AD because of the appearing beneficial effects of LXR on glucose homeostasis. The ability of LXR to attenuate AD pathology makes them potential therapeutic targets for this neurodegenerative disease.
Collapse
Affiliation(s)
- Jihong Kang
- Department of Physiology and Pathophysiology and Key Laboratory of Molecular Cardiovascular Sciences, State Education Ministry, Peking University Health Science Center, Beijing 100191, China
| | | |
Collapse
|
17
|
García-Mediavilla MV, Pisonero-Vaquero S, Lima-Cabello E, Benedicto I, Majano PL, Jorquera F, González-Gallego J, Sánchez-Campos S. Liver X receptor α-mediated regulation of lipogenesis by core and NS5A proteins contributes to HCV-induced liver steatosis and HCV replication. J Transl Med 2012; 92:1191-202. [PMID: 22641099 DOI: 10.1038/labinvest.2012.88] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Molecular mechanisms contributing to hepatitis C virus (HCV)-associated steatosis are not well established, although HCV gene expression has been shown to alter host cell cholesterol/lipid metabolism. As liver X receptors (LXRs) play a role as key modulators of metabolism signaling in the development of steatosis, we aimed to investigate in an HCV in vitro model the effect of HCV NS5A protein, core protein, and viral replication on the intracellular lipid accumulation and the LXRα-regulated expression of lipogenic genes. The effects of LXRα siRNA or agonist GW3965 treatment on lipogenesis and HCV replication capacity in our HCV replicon system were also examined. NS5A- and core-expressing cells and replicon-containing cells exhibited an increase of lipid accumulation by inducing the gene expression and the transcriptional activity of LXRα, and leading to an increased expression of its lipogenic target genes sterol regulatory element binding protein-1c, peroxisome proliferator-activated receptor-γ, and fatty acid synthase. Transcriptional induction by NS5A protein, core protein, and viral replication occurred via LXR response element activation in the lipogenic gene promoter. No physical association between HCV proteins and LXRα was observed, whereas NS5A and core proteins indirectly upregulated LXRα through the phosphatidylinositol 3-kinase pathway. Finally, it was found that LXRα knockdown or agonist-mediated LXRα induction directly regulated HCV-induced lipogenesis and HCV replication efficiency in replicon-containing cells. Combined, our data suggest that LXRα-mediated regulation of lipogenesis by core and NS5A proteins may contribute to HCV-induced liver steatosis and to the efficient replication of HCV.
Collapse
|
18
|
PAPP-A negatively regulates ABCA1, ABCG1 and SR-B1 expression by inhibiting LXRα through the IGF-I-mediated signaling pathway. Atherosclerosis 2012; 222:344-54. [DOI: 10.1016/j.atherosclerosis.2012.03.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2011] [Revised: 02/16/2012] [Accepted: 03/06/2012] [Indexed: 01/14/2023]
|
19
|
Zhu R, Ou Z, Ruan X, Gong J. Role of liver X receptors in cholesterol efflux and inflammatory signaling (review). Mol Med Rep 2012; 5:895-900. [PMID: 22267249 PMCID: PMC3493071 DOI: 10.3892/mmr.2012.758] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Accepted: 12/27/2011] [Indexed: 01/10/2023] Open
Abstract
Liver X receptors (LXRs) are nuclear receptors that play a central role in cholesterol metabolism. When activated, LXRs induce a series of genes that are involved in cholesterol efflux, absorption, transport and excretion. In recent studies, LXRs have also been shown to play an important role in inflammatory signaling. LXR agonists show promise as potential therapeutics, given their anti-atherogenic and anti-inflammatory properties. The function of LXRs in cholesterol efflux and inflammatory signaling make them attractive as therapies for cardiovascular and inflammatory diseases.
Collapse
Affiliation(s)
- Rongtao Zhu
- Department of Hepatobiliary Surgery, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, PR China
| | | | | | | |
Collapse
|
20
|
Subramanian G, Chaudhury P, Malu K, Fowler S, Manmode R, Gotur D, Zwerger M, Ryan D, Roberti R, Gaines P. Lamin B receptor regulates the growth and maturation of myeloid progenitors via its sterol reductase domain: implications for cholesterol biosynthesis in regulating myelopoiesis. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2012; 188:85-102. [PMID: 22140257 PMCID: PMC3244548 DOI: 10.4049/jimmunol.1003804] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Lamin B receptor (LBR) is a bifunctional nuclear membrane protein with N-terminal lamin B and chromatin-binding domains plus a C-terminal sterol Δ(14) reductase domain. LBR expression increases during neutrophil differentiation, and deficient expression disrupts neutrophil nuclear lobulation characteristic of Pelger-Huët anomaly. Thus, LBR plays a critical role in regulating myeloid differentiation, but how the two functional domains of LBR support this role is currently unclear. We previously identified abnormal proliferation and deficient functional maturation of promyelocytes (erythroid, myeloid, and lymphoid [EML]-derived promyelocytes) derived from EML-ic/ic cells, a myeloid model of ichthyosis (ic) bone marrow that lacks Lbr expression. In this study, we provide new evidence that cholesterol biosynthesis is important to myeloid cell growth and is supported by the sterol reductase domain of Lbr. Cholesterol biosynthesis inhibitors caused growth inhibition of EML cells that increased in EML-derived promyelocytes, whereas cells lacking Lbr exhibited complete growth arrest at both stages. Lipid production increased during wild-type neutrophil maturation, but ic/ic cells exhibited deficient levels of lipid and cholesterol production. Ectopic expression of a full-length Lbr in EML-ic/ic cells rescued both nuclear lobulation and growth arrest in cholesterol starvation conditions. Lipid production also was rescued, and a deficient respiratory burst was corrected. Expression of just the C-terminal sterol reductase domain of Lbr in ic/ic cells also improved each of these phenotypes. Our data support the conclusion that the sterol Δ(14) reductase domain of LBR plays a critical role in cholesterol biosynthesis and that this process is essential to both myeloid cell growth and functional maturation.
Collapse
Affiliation(s)
- Gayathri Subramanian
- Department of Biological Sciences, University of Massachusetts Lowell, Lowell, MA, USA
| | - Pulkit Chaudhury
- Department of Biological Sciences, University of Massachusetts Lowell, Lowell, MA, USA
| | - Krishnakumar Malu
- Department of Biological Sciences, University of Massachusetts Lowell, Lowell, MA, USA
| | - Samantha Fowler
- Department of Biological Sciences, University of Massachusetts Lowell, Lowell, MA, USA
| | - Rahul Manmode
- Department of Chemistry, University of Massachusetts Lowell, Lowell, MA, USA
| | - Deepali Gotur
- Department of Biological Sciences, University of Massachusetts Lowell, Lowell, MA, USA
| | - Monika Zwerger
- Department of Molecular Genetics, German Cancer Research Center, 69120 Heidelberg, Germany
| | - David Ryan
- Department of Chemistry, University of Massachusetts Lowell, Lowell, MA, USA
| | - Rita Roberti
- Department of Internal Medicine, Laboratory of Biochemistry, University of Perugia, via del Giochetto, 06122 Perugia, Italy
| | - Peter Gaines
- Department of Biological Sciences, University of Massachusetts Lowell, Lowell, MA, USA
| |
Collapse
|
21
|
Curcumin promotes cholesterol efflux from adipocytes related to PPARgamma-LXRalpha-ABCA1 passway. Mol Cell Biochem 2011; 358:281-5. [PMID: 21748336 DOI: 10.1007/s11010-011-0978-z] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Accepted: 06/29/2011] [Indexed: 12/20/2022]
Abstract
Curcumin affects the functions of adipocytes. But it is not known whether curcumin has some effect on the cholesterol efflux process of adipocytes. Rabbit subcutaneous adipocytes were incubated with 5, 10 and 20 μg/ml curcumin for 24 h. The cholesterol efflux onto apoAI was assessed, and the peroxisome proliferators-activated receptor (PPAR) γ, liver X receptor (LXR) α and ATP-binding cassette transporter A1 (ABCA1) mRNA expression in adipocytes were quantified by reverse-transcription polymerase chain reaction (RT-PCR). Curcumin increased the cholesterol efflux from adipocytes in dose-dependent manner. The increased expression of PPARγ, LXRα and ABCA1 caused by curcumin were parallel. When the adipocytes were pre-treated by GW9662, the increased expression of PPARγ induced by curcumin was partially prevented, subsequent to the down-regulation of LXRα and ABCA1. Curcumin can affect the cholesterol efflux from adipocytes by regulating the PPARγ-LXR-ABCA1 passway.
Collapse
|