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Wang W, Chen X, Chen J, Xu M, Liu Y, Yang S, Zhao W, Tan S. Engineering lentivirus envelope VSV-G for liver targeted delivery of IDOL-shRNA to ameliorate hypercholesterolemia and atherosclerosis. MOLECULAR THERAPY. NUCLEIC ACIDS 2024; 35:102115. [PMID: 38314097 PMCID: PMC10835450 DOI: 10.1016/j.omtn.2024.102115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Accepted: 01/05/2024] [Indexed: 02/06/2024]
Abstract
Lentiviral vectors (LVs) have been widely used as a tool for gene therapies. However, tissue-selective transduction after systemic delivery remains a challenge. Inducible degrader of low-density lipoprotein receptor is an attractive target for treating hypercholesterolemia. Here, a liver-targeted LV, CS8-LV-shIDOL, is developed by incorporating a hepatocyte-targeted peptide derived from circumsporozoite protein (CSP) into the lentivirus envelope for liver-targeted delivery of IDOL-shRNA (short hairpin RNA) to alleviate hypercholesterolemia. Tail-vein injection of CS8-LV-shIDOL results in extremely high accumulation in liver and nearly undetectable levels in other organs in mice. In addition, it shows superior therapeutic efficacy in lowering serum low-density lipoprotein cholesterol (LDL-C) and reducing atherosclerotic lesions over unmodified LV-shIDOL in hyperlipidemic mice. Mechanically, the envelope-engineered CS8-LV-shIDOL can enter liver cells via low-density lipoprotein receptor-related protein (LRP). Thus, this study provides a novel approach for liver-targeted delivery of IDOL-shRNA to treat hypercholesterolemia by using an envelope-engineered LV, and this delivery system has great potential for liver-targeted transgene therapy.
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Affiliation(s)
- Wei Wang
- Department of Cell and Molecular Biology, School of Life Science and Technology, State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, Nanjing 210009, China
| | - Xuemei Chen
- Department of Cell and Molecular Biology, School of Life Science and Technology, State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, Nanjing 210009, China
| | - Jiali Chen
- Department of Cell and Molecular Biology, School of Life Science and Technology, State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, Nanjing 210009, China
| | - Menglong Xu
- Department of Cell and Molecular Biology, School of Life Science and Technology, State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, Nanjing 210009, China
| | - Ying Liu
- Department of Cell and Molecular Biology, School of Life Science and Technology, State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, Nanjing 210009, China
| | - Shijie Yang
- Department of Cell and Molecular Biology, School of Life Science and Technology, State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, Nanjing 210009, China
| | - Wenfeng Zhao
- Department of Cell and Molecular Biology, School of Life Science and Technology, State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, Nanjing 210009, China
| | - Shuhua Tan
- Department of Cell and Molecular Biology, School of Life Science and Technology, State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, Nanjing 210009, China
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2
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Huang Y, Liu FY, Yang JT, Zhao Q, Zhu MQ, Wang J, Long SY, Tuo QH, Zhang CP, Lin LM, Liao DF. Curcumin nicotinate increases LDL cholesterol uptake in hepatocytes through IDOL/LDL-R pathway regulation. Eur J Pharmacol 2024; 966:176352. [PMID: 38290567 DOI: 10.1016/j.ejphar.2024.176352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 01/17/2024] [Accepted: 01/22/2024] [Indexed: 02/01/2024]
Abstract
BACKGROUND Curcumin nicotinate (Curtn), derived from curcumin and niacin, reduces serum LDL-C levels, partly due to its influence on PCSK9. This study investigates IDOL's role in Curtn's lipid-lowering effects. OBJECTIVE To elucidate Curtn's regulation of the IDOL/LDLR pathway and potential molecular mechanisms in hepatocytes. METHODS Differential metabolites in Curtn-treated HepG2 cells were identified via LC-MS. Molecular docking assessed Curtn's affinity with IDOL. Cholesterol content and LDLR expression effects were studied in high-fat diet Wistar rats. In vitro evaluations determined Curtn's influence on IDOL overexpression's LDL-C uptake and LDLR expression in hepatocytes. RESULTS Lipids were the main differential metabolites in Curtn-treated HepG2 cells. Docking showed Curtn's higher affinity to IDOL's FERM domain compared to curcumin, suggesting potential competitive inhibition of IDOL's binding to LDLR. Curtn decreased liver cholesterol in Wistar rats and elevated LDLR expression. During in vitro experiments, Curtn significantly enhanced the effects of IDOL overexpression in HepG2 cells, leading to increased LDL-C uptake and elevated expression of LDL receptors. CONCLUSION Curtn modulates the IDOL/LDLR pathway, enhancing LDL cholesterol uptake in hepatocytes. Combined with its PCSK9 influence, Curtn emerges as a potential hyperlipidemia therapy.
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Affiliation(s)
- Ying Huang
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Med-icine, Changsha, 410208, Hunan, China; Shenzhen Samii Medical Center, Shenzhen, 518118, Guangdong, China.
| | - Fang-Yuan Liu
- Department of Biochemistry & Molecular Biology, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China.
| | - Jia-Tao Yang
- Department of Biochemistry & Molecular Biology, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China.
| | - Qian Zhao
- Department of Biochemistry & Molecular Biology, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China.
| | - Mei-Qi Zhu
- Department of Biochemistry & Molecular Biology, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China.
| | - Jing Wang
- Department of Biochemistry & Molecular Biology, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China.
| | - Shi-Yin Long
- Department of Biochemistry & Molecular Biology, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China.
| | - Qin-Hui Tuo
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Med-icine, Changsha, 410208, Hunan, China.
| | - Cai-Ping Zhang
- Department of Biochemistry & Molecular Biology, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China.
| | - Li-Mei Lin
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Med-icine, Changsha, 410208, Hunan, China.
| | - Duan-Fang Liao
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Med-icine, Changsha, 410208, Hunan, China.
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Aldworth H, Hooper NM. Post-translational regulation of the low-density lipoprotein receptor provides new targets for cholesterol regulation. Biochem Soc Trans 2024; 52:431-440. [PMID: 38329179 PMCID: PMC10903450 DOI: 10.1042/bst20230918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 01/16/2024] [Accepted: 01/17/2024] [Indexed: 02/09/2024]
Abstract
The amount of the low-density lipoprotein receptor (LDLR) on the surface of hepatocytes is the primary determinant of plasma low-density lipoprotein (LDL)-cholesterol level. Although the synthesis and cellular trafficking of the LDLR have been well-documented, there is growing evidence of additional post-translational mechanisms that regulate or fine tune the surface availability of the LDLR, thus modulating its ability to bind and internalise LDL-cholesterol. Proprotein convertase subtilisin/kexin type 9 and the asialoglycoprotein receptor 1 both independently interact with the LDLR and direct it towards the lysosome for degradation. While ubiquitination by the E3 ligase inducible degrader of the LDLR also targets the receptor for lysosomal degradation, ubiquitination of the LDLR by a different E3 ligase, RNF130, redistributes the receptor away from the plasma membrane. The activity of the LDLR is also regulated by proteolysis. Proteolytic cleavage of the transmembrane region of the LDLR by γ-secretase destabilises the receptor, directing it to the lysosome for degradation. Shedding of the extracellular domain of the receptor by membrane-type 1 matrix metalloprotease and cleavage of the receptor in its LDL-binding domain by bone morphogenetic protein-1 reduces the ability of the LDLR to bind and internalise LDL-cholesterol at the cell surface. A better understanding of how the activity of the LDLR is regulated will not only unravel the complex biological mechanisms controlling LDL-cholesterol metabolism but also could help inform the development of alternative pharmacological intervention strategies for the treatment of hypercholesterolaemia.
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Affiliation(s)
- Harry Aldworth
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, U.K
| | - Nigel M Hooper
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, U.K
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4
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Gawden-Bone CM, Lehner PJ, Volkmar N. As a matter of fat: Emerging roles of lipid-sensitive E3 ubiquitin ligases. Bioessays 2023; 45:e2300139. [PMID: 37890275 DOI: 10.1002/bies.202300139] [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: 07/28/2023] [Revised: 09/22/2023] [Accepted: 09/26/2023] [Indexed: 10/29/2023]
Abstract
The dynamic structure and composition of lipid membranes need to be tightly regulated to control the vast array of cellular processes from cell and organelle morphology to protein-protein interactions and signal transduction pathways. To maintain membrane integrity, sense-and-response systems monitor and adjust membrane lipid composition to the ever-changing cellular environment, but only a relatively small number of control systems have been described. Here, we explore the emerging role of the ubiquitin-proteasome system in monitoring and maintaining membrane lipid composition. We focus on the ER-resident RNF145 E3 ubiquitin ligase, its role in regulating adiponectin receptor 2 (ADIPOR2), its lipid hydrolase substrate, and the broader implications for understanding the homeostatic processes that fine-tune cellular membrane composition.
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Affiliation(s)
- Christian M Gawden-Bone
- Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID), Jeffrey Cheah Biomedical Centre, University of Cambridge, Cambridge, UK
| | - Paul J Lehner
- Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID), Jeffrey Cheah Biomedical Centre, University of Cambridge, Cambridge, UK
| | - Norbert Volkmar
- Institute for Molecular Systems Biology (IMSB), ETH Zürich, Zürich, Switzerland
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5
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Morales SV, Mahmood A, Pollard J, Mayne J, Figeys D, Wiseman PW. The LDL receptor is regulated by membrane cholesterol as revealed by fluorescence fluctuation analysis. Biophys J 2023; 122:3783-3797. [PMID: 37559362 PMCID: PMC10541495 DOI: 10.1016/j.bpj.2023.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 06/17/2023] [Accepted: 08/07/2023] [Indexed: 08/11/2023] Open
Abstract
Membrane cholesterol-rich domains have been shown to be important for regulating a range of membrane protein activities. Low-density lipoprotein receptor (LDLR)-mediated internalization of cholesterol-rich LDL particles is tightly regulated by feedback mechanisms involving intracellular sterol sensors. Since LDLR plays a role in maintaining cellular cholesterol homeostasis, we explore the role that membrane domains may have in regulating LDLR activity. We expressed a fluorescent LDLR-mEGFP construct in HEK293T cells and imaged the unligated receptor or bound to an LDL/DiI fluorescent ligand using total internal reflection fluorescence microscopy. We studied the receptor's spatiotemporal dynamics using fluorescence fluctuation analysis methods. Image cross correlation spectroscopy reveals a lower LDL-to-LDLR binding fraction when membrane cholesterol concentrations are augmented using cholesterol esterase, and a higher binding fraction when the cells are treated with methyl-β-cyclodextrin) to lower membrane cholesterol. This suggests that LDLR's ability to metabolize LDL particles is negatively correlated to membrane cholesterol concentrations. We then tested if a change in activity is accompanied by a change in membrane localization. Image mean-square displacement analysis reveals that unligated LDLR-mEGFP and ligated LDLR-mEGFP/LDL-DiI constructs are transiently confined on the cell membrane, and the size of their confinement domains increases with augmented cholesterol concentrations. Receptor diffusion within the domains and their domain-escape probabilities decrease upon treatment with methyl-β-cyclodextrin, consistent with a change in receptor populations to more confined domains, likely clathrin-coated pits. We propose a feedback model to account for regulation of LDLR within the cell membrane: when membrane cholesterol concentrations are high, LDLR is sequestered in cholesterol-rich domains. These LDLR populations are attenuated in their efficacy to bind and internalize LDL. However, when membrane cholesterol levels drop, LDL has a higher binding affinity to its receptor and the LDLR transits to nascent clathrin-coated domains, where it diffuses at a slower rate while awaiting internalization.
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Affiliation(s)
- Sebastian V Morales
- Department of Chemistry, Faculty of Science, McGill University, Montreal, Canada
| | - Ahmad Mahmood
- Department of Physics, Faculty of Science, McGill University, Montreal, Canada
| | - Jacob Pollard
- Department of Chemistry, Faculty of Science, McGill University, Montreal, Canada
| | - Janice Mayne
- School of Pharmaceutical Sciences, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Daniel Figeys
- School of Pharmaceutical Sciences, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Paul W Wiseman
- Department of Chemistry, Faculty of Science, McGill University, Montreal, Canada; Department of Physics, Faculty of Science, McGill University, Montreal, Canada.
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Uppal S, Postnikova O, Villasmil R, Rogozin IB, Bocharov AV, Eggerman TL, Poliakov E, Redmond TM. Low-Density Lipoprotein Receptor (LDLR) Is Involved in Internalization of Lentiviral Particles Pseudotyped with SARS-CoV-2 Spike Protein in Ocular Cells. Int J Mol Sci 2023; 24:11860. [PMID: 37511618 PMCID: PMC10380832 DOI: 10.3390/ijms241411860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/16/2023] [Accepted: 07/17/2023] [Indexed: 07/30/2023] Open
Abstract
Here, we present evidence that caveolae-mediated endocytosis using LDLR is the pathway for SARS-CoV-2 virus internalization in the ocular cell line ARPE-19. Firstly, we found that, while Angiotensin-converting enzyme 2 (ACE2) is expressed in these cells, blocking ACE2 by antibody treatment did not prevent infection by SARS-CoV-2 spike pseudovirions, nor did antibody blockade of extracellular vimentin and other cholesterol-rich lipid raft proteins. Next, we implicated the role of cholesterol homeostasis in infection by showing that incubating cells with different cyclodextrins and oxysterol 25-hydroxycholesterol (25-HC) inhibits pseudovirion infection of ARPE-19. However, the effect of 25-HC is likely not via cholesterol biosynthesis, as incubation with lovastatin did not appreciably affect infection. Additionally, is it not likely to be an agonistic effect of 25-HC on LXR receptors, as the LXR agonist GW3965 had no significant effect on infection of ARPE-19 cells at up to 5 μM GW3965. We probed the role of endocytic pathways but determined that clathrin-dependent and flotillin-dependent rafts were not involved. Furthermore, 20 µM chlorpromazine, an inhibitor of clathrin-mediated endocytosis (CME), also had little effect. In contrast, anti-dynamin I/II antibodies blocked the entry of SARS-CoV-2 spike pseudovirions, as did dynasore, a noncompetitive inhibitor of dynamin GTPase activity. Additionally, anti-caveolin-1 antibodies significantly blocked spike pseudotyped lentiviral infection of ARPE-19. However, nystatin, a classic inhibitor of caveolae-dependent endocytosis, did not affect infection while indomethacin inhibited only at 10 µM at the 48 h time point. Finally, we found that anti-LDLR antibodies block pseudovirion infection to a similar degree as anti-caveolin-1 and anti-dynamin I/II antibodies, while transfection with LDLR-specific siRNA led to a decrease in spike pseudotyped lentiviral infection, compared to scrambled control siRNAs. Thus, we conclude that SARS-CoV-2 spike pseudovirion infection in ARPE-19 cells is a dynamin-dependent process that is primarily mediated by LDLR.
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Affiliation(s)
- Sheetal Uppal
- Laboratory of Retinal Cell & Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Olga Postnikova
- Laboratory of Retinal Cell & Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Rafael Villasmil
- Flow Cytometry Core Facility, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Igor B Rogozin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | | | - Thomas L Eggerman
- Clinical Center, National Institutes of Health, Bethesda, MD 20894, USA
- National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Eugenia Poliakov
- Laboratory of Retinal Cell & Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - T Michael Redmond
- Laboratory of Retinal Cell & Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
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7
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Li Z, He M, Chen G, Souaiaia T, Worgall TS, Jiang XC. Effect of Total SMS Activity on LDL Catabolism in Mice. Arterioscler Thromb Vasc Biol 2023; 43:1251-1261. [PMID: 37128925 PMCID: PMC10330209 DOI: 10.1161/atvbaha.123.319031] [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: 02/02/2023] [Accepted: 04/06/2023] [Indexed: 05/03/2023]
Abstract
BACKGROUND Sphingomyelin (SM) and cholesterol are 2 key lipid partners on cell membranes and on lipoproteins. Many studies have indicated the influence of cholesterol on SM metabolism. This study examined the influence of SM biosynthesis on cholesterol metabolism. METHODS Inducible global Sms1 KO (knockout)/global Sms2 KO mice were prepared to evaluate the effect of whole-body SM biosynthesis deficiency on lipoprotein metabolism. Tissue cholesterol, SM, ceramide, and glucosylceramide levels were measured. Triglyceride production rate and LDL (low-density lipoprotein) catabolism were measured. Lipid rafts were isolated and LDL receptor mass and function were evaluated. Also, the effects of exogenous sphingolipids on hepatocytes were investigated. RESULTS We found that total SMS (SM synthase) depletion significantly reduced plasma SM levels. Also, the total deficiency significantly induced plasma cholesterol, apoB (apolipoprotein B), and apoE (apolipoprotein E) levels. Importantly, total SMS deficiency, but not SMS2 deficiency, dramatically decreased LDL receptors in the liver and attenuated LDL uptake through the receptor. Further, we found that total SMS deficiency greatly reduced LDL receptors in the lipid rafts, which contained significantly lower SM and significantly higher glucosylceramide, as well as cholesterol. Furthermore, we treated primary hepatocytes and Huh7 cells (a human hepatoma cell line) with SM, ceramide, or glucosylceramide, and we found that only SM could upregulate LDL receptor levels in a dose-dependent fashion. CONCLUSIONS Whole-body SM biosynthesis plays an important role in LDL cholesterol catabolism. The total SMS deficiency, but not SMS2 deficiency, reduces LDL uptake and causes LDL cholesterol accumulation in the circulation. Given the fact that serum SM level is a risk factor for cardiovascular diseases, inhibiting SMS2 but not SMS1 should be the desirable approach.
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Affiliation(s)
- Zhiqiang Li
- Department of Cell Biology, State University of New York, Downstate Health Sciences University, Brooklyn (Z.L., M.H., G.C., T.S., X.-C.J.)
- Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System (Z.L., X.-C.J.)
| | - Mulin He
- Department of Cell Biology, State University of New York, Downstate Health Sciences University, Brooklyn (Z.L., M.H., G.C., T.S., X.-C.J.)
| | - Guangzhi Chen
- Department of Cell Biology, State University of New York, Downstate Health Sciences University, Brooklyn (Z.L., M.H., G.C., T.S., X.-C.J.)
| | - Tade Souaiaia
- Department of Cell Biology, State University of New York, Downstate Health Sciences University, Brooklyn (Z.L., M.H., G.C., T.S., X.-C.J.)
| | - Tilla S Worgall
- Department of Pathology and Cell Biology, Columbia University, New York (T.S.W.)
| | - Xian-Cheng Jiang
- Department of Cell Biology, State University of New York, Downstate Health Sciences University, Brooklyn (Z.L., M.H., G.C., T.S., X.-C.J.)
- Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System (Z.L., X.-C.J.)
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8
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Effect of Total Sphingomyelin Synthase Activity on Low Density Lipoprotein Catabolism in Mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.03.527088. [PMID: 36798262 PMCID: PMC9934588 DOI: 10.1101/2023.02.03.527088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Background Sphingomyelin (SM) and cholesterol are two key lipid partners on cell membranes and on lipoproteins. Many studies have indicated the influence of cholesterol on SM metabolism. This study examined the influence of SM biosynthesis on cholesterol metabolism. Methods Inducible global Sms1 KO/global Sms2 KO mice were prepared to evaluate the effect of whole-body SM biosynthesis deficiency on lipoprotein metabolism. Tissue cholesterol, SM, ceramide, and glucosylceramide levels were measured. TG production rate and LDL catabolism were measured. Lipid rafts were isolated and LDL receptor mass and function were evaluated. Also, the effects of exogenous sphingolipids on hepatocytes were investigated. Results We found that total SMS depletion significantly reduced plasma SM levels. Also, the total deficiency significantly induced plasma cholesterol, apoB, and apoE levels. Importantly, total SMS deficiency, but not SMS2 deficiency, dramatically decreased LDL receptors in the liver and attenuated LDL uptake through the receptor. Further, we found that total SMS deficiency greatly reduced LDL receptors in the lipid rafts which contained significantly lower SM and significantly higher glucosylceramide as well as cholesterol. Furthermore, we treated primary hepatocytes and Huh7 cells (a human hepatoma cell line) with SM, ceramide, or glucosylceramide, and we found that only SM could up-regulate LDL receptor levels in a dose-dependent fashion. Conclusions Whole-body SM biosynthesis plays an important role in LDL-cholesterol catabolism. The total SMS deficiency, but not SMS2 deficiency, reduces LDL uptake and causes LDL-cholesterol accumulation in the circulation. Given the fact that serum SM level is a risk factor for cardiovascular diseases, inhibiting SMS2 but not SMS1 should be the desirable approach. Graphic Abstract
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9
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Hepatitis C Virus-Lipid Interplay: Pathogenesis and Clinical Impact. Biomedicines 2023; 11:biomedicines11020271. [PMID: 36830808 PMCID: PMC9953247 DOI: 10.3390/biomedicines11020271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 01/13/2023] [Accepted: 01/16/2023] [Indexed: 01/20/2023] Open
Abstract
Hepatitis C virus (HCV) infection represents the major cause of chronic liver disease, leading to a wide range of hepatic diseases, including cirrhosis and hepatocellular carcinoma. It is the leading indication for liver transplantation worldwide. In addition, there is a growing body of evidence concerning the role of HCV in extrahepatic manifestations, including immune-related disorders and metabolic abnormalities, such as insulin resistance and steatosis. HCV depends on its host cells to propagate successfully, and every aspect of the HCV life cycle is closely related to human lipid metabolism. The virus circulates as a lipid-rich particle, entering the hepatocyte via lipoprotein cell receptors. It has also been shown to upregulate lipid biosynthesis and impair lipid degradation, resulting in significant intracellular lipid accumulation (steatosis) and circulating hypocholesterolemia. Patients with chronic HCV are at increased risk for hepatic steatosis, dyslipidemia, and cardiovascular disease, including accelerated atherosclerosis. This review aims to describe different aspects of the HCV viral life cycle as it impacts host lipoproteins and lipid metabolism. It then discusses the mechanisms of HCV-related hepatic steatosis, hypocholesterolemia, and accelerated atherosclerosis.
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10
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Qin Y, Medina MW. Mechanism of the Regulation of Plasma Cholesterol Levels by PI(4,5)P 2. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1422:89-119. [PMID: 36988878 DOI: 10.1007/978-3-031-21547-6_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
Elevated low-density lipoprotein (LDL) cholesterol (LDLc) is one of the most well-established risk factors for cardiovascular disease, while high levels of high-density lipoprotein (HDL) cholesterol (HDLc) have been associated with protection from cardiovascular disease. Cardiovascular disease remains one of the leading causes of death worldwide; thus it is important to understand mechanisms that impact LDLc and HDLc metabolism. In this chapter, we will discuss molecular processes by which phosphatidylinositol-(4,5)-bisphosphate, PI(4,5)P2, is thought to modulate LDLc or HDLc. Section 1 will provide an overview of cholesterol in the circulation, discussing processes that modulate the various forms of lipoproteins (LDL and HDL) carrying cholesterol. Section 2 will describe how a PI(4,5)P2 phosphatase, transmembrane protein 55B (TMEM55B), impacts circulating LDLc levels through its ability to regulate lysosomal decay of the low-density lipoprotein receptor (LDLR), the primary receptor for hepatic LDL uptake. Section 3 will discuss how PI(4,5)P2 interacts with apolipoprotein A-I (apoA1), the key apolipoprotein on HDL. In addition to direct mechanisms of PI(4,5)P2 action on circulating cholesterol, Sect. 4 will review how PI(4,5)P2 may indirectly impact LDLc and HDLc by affecting insulin action. Last, as cholesterol is controlled through intricate negative feedback loops, Sect. 5 will describe how PI(4,5)P2 is regulated by cholesterol.
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Affiliation(s)
- Yuanyuan Qin
- Department of Pediatrics, Division of Cardiology, University of California, San Francisco, Oakland, CA, USA
| | - Marisa W Medina
- Department of Pediatrics, Division of Cardiology, University of California, San Francisco, Oakland, CA, USA.
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11
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Ravera A, Santema BT, de Boer RA, Anker SD, Samani NJ, Lang CC, Ng L, Cleland JGF, Dickstein K, Lam CSP, Van Spall HGC, Filippatos G, van Veldhuisen DJ, Metra M, Voors AA, Sama IE. Distinct pathophysiological pathways in women and men with heart failure. Eur J Heart Fail 2022; 24:1532-1544. [PMID: 35596674 DOI: 10.1002/ejhf.2534] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 04/06/2022] [Accepted: 05/06/2022] [Indexed: 11/07/2022] Open
Abstract
AIMS Clinical differences between women and men have been described in heart failure (HF). However, less is known about the underlying pathophysiological mechanisms. In this study, we compared multiple circulating biomarkers to gain better insights into differential HF pathophysiology between women and men. METHODS AND RESULTS In 537 women and 1485 men with HF, we compared differential expression of a panel of 363 biomarkers. Then, we performed a pathway over-representation analysis to identify differential biological pathways in women and men. Findings were validated in an independent HF cohort (575 women, 1123 men). In both cohorts, women were older and had higher left ventricular ejection fraction (LVEF). In the index and validation cohorts respectively, we found 14/363 and 12/363 biomarkers that were relatively up-regulated in women, while 21/363 and 14/363 were up-regulated in men. In both cohorts, the strongest up-regulated biomarkers in women were leptin and fatty acid binding protein-4, compared to matrix metalloproteinase-3 in men. Similar findings were replicated in a subset of patients from both cohorts matched by age and LVEF. Pathway over-representation analysis revealed increased activity of pathways associated with lipid metabolism in women, and neuro-inflammatory response in men (all p < 0.0001). CONCLUSION In two independent cohorts of HF patients, biomarkers associated with lipid metabolic pathways were observed in women, while biomarkers associated with neuro-inflammatory response were more active in men. Differences in inflammatory and metabolic pathways may contribute to sex differences in clinical phenotype observed in HF, and provide useful insights towards development of tailored HF therapies.
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Affiliation(s)
- Alice Ravera
- Institute of Cardiology, ASST Spedali Civili di Brescia, and Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy.,University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Bernadet T Santema
- University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Rudolf A de Boer
- University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Stefan D Anker
- Division of Cardiology and Metabolism, Department of Cardiology (CVK) and Berlin-Brandenburg Center for Regenerative Therapies (BCRT), German Centre for Cardiovascular Research (DZHK) Partner Site Berlin, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Nilesh J Samani
- Department of Cardiovascular Sciences, University of Leicester, NIHR (National Institute for Health Research) Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, UK
| | - Chim C Lang
- School of Medicine Centre for Cardiovascular and Lung Biology, Division of Molecular and Clinical Medicine, University of Dundee, Ninewells Hospital & Medical School, Dundee, UK
| | - Leong Ng
- Department of Cardiovascular Sciences, University of Leicester, NIHR (National Institute for Health Research) Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, UK
| | - John G F Cleland
- National Heart and Lung Institute, Royal Brompton and Harefield Hospitals, Imperial College, London, UK.,Robertson Centre for Biostatistics and Clinical Trials, University of Glasgow, Glasgow, UK
| | - Kenneth Dickstein
- University of Bergen, Stavanger University Hospital, Stavanger, Norway
| | - Carolyn S P Lam
- National Heart Centre Singapore, Duke-National University of Singapore, Singapore, Singapore
| | - Harriette G C Van Spall
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada.,Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada.,Population Health Research Institute, Hamilton, Ontario, Canada
| | - Gerasimos Filippatos
- National and Kapodistrian University of Athens, Athens University Hospital Attikon, Athens, Greece
| | - Dirk J van Veldhuisen
- University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Marco Metra
- Institute of Cardiology, ASST Spedali Civili di Brescia, and Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
| | - Adriaan A Voors
- University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Iziah E Sama
- University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
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12
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Gundu C, Arruri VK, Yadav P, Navik U, Kumar A, Amalkar VS, Vikram A, Gaddam RR. Dynamin-Independent Mechanisms of Endocytosis and Receptor Trafficking. Cells 2022; 11:cells11162557. [PMID: 36010634 PMCID: PMC9406725 DOI: 10.3390/cells11162557] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 08/03/2022] [Accepted: 08/13/2022] [Indexed: 11/16/2022] Open
Abstract
Endocytosis is a fundamental mechanism by which cells perform housekeeping functions. It occurs via a variety of mechanisms and involves many regulatory proteins. The GTPase dynamin acts as a “molecular scissor” to form endocytic vesicles and is a critical regulator among the proteins involved in endocytosis. Some GTPases (e.g., Cdc42, arf6, RhoA), membrane proteins (e.g., flotillins, tetraspanins), and secondary messengers (e.g., calcium) mediate dynamin-independent endocytosis. These pathways may be convergent, as multiple pathways exist in a single cell. However, what determines the specific path of endocytosis is complex and challenging to comprehend. This review summarizes the mechanisms of dynamin-independent endocytosis, the involvement of microRNAs, and factors that contribute to the cellular decision about the specific route of endocytosis.
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Affiliation(s)
- Chayanika Gundu
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad 500037, Telangana, India
| | - Vijay Kumar Arruri
- Department of Neurological Surgery, University of Wisconsin, Madison, WI 53792, USA
| | - Poonam Yadav
- Department of Pharmacology, Central University of Punjab, Bathinda 151001, Punjab, India
| | - Umashanker Navik
- Department of Pharmacology, Central University of Punjab, Bathinda 151001, Punjab, India
| | - Ashutosh Kumar
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Kolkata 700054, West Bengal, India
| | - Veda Sudhir Amalkar
- Department of Internal Medicine, Carver College of Medicine, The University of Iowa, Iowa City, IA 52242, USA
| | - Ajit Vikram
- Department of Internal Medicine, Carver College of Medicine, The University of Iowa, Iowa City, IA 52242, USA
| | - Ravinder Reddy Gaddam
- Department of Internal Medicine, Carver College of Medicine, The University of Iowa, Iowa City, IA 52242, USA
- Correspondence:
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13
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PCSK9 deficiency results in a specific shedding of excess LDLR in female mice only: Role of hepatic cholesterol. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159217. [PMID: 35985474 DOI: 10.1016/j.bbalip.2022.159217] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 08/03/2022] [Accepted: 08/04/2022] [Indexed: 11/24/2022]
Abstract
PCSK9 promotes the lysosomal degradation of cell surface LDL receptor (LDLR). We analyzed how excess LDLR generated by PCSK9 deficiency is differently handled in male and female mice to possibly unveil the mechanism leading to the lower efficacy of PCSK9 mAb on LDL-cholesterol levels in women. Analysis of intact or ovariectomized PCSK9 knockout (KO) mice supplemented with placebo or 17β-estradiol (E2) demonstrated that female, but not male mice massively shed the soluble ectodomain of the LDLR in the plasma. Liver-specific PCSK9 KO or alirocumab-treated WT mice exhibit the same pattern. This shedding is distinct from the basal one and is inhibited by ZLDI-8, a metalloprotease inhibitor pointing at ADAM10/ADAM17. In PCSK9 KO female mice, ZLDI-8 raises by 80 % the LDLR liver content in a few hours. This specific shedding is likely cholesterol-dependent: it is prevented in PCSK9 KO male mice that exhibit low intra-hepatic cholesterol levels without activating SREBP-2, and enhanced by mevalonate or high cholesterol feeding, or by E2 known to stimulate cholesterol synthesis via the estrogen receptor-α. Liver transcriptomics demonstrates that critically low liver cholesterol in ovariectomized female or knockout male mice also hampers the cholesterol-dependent G2/M transition of the cell cycle. Finally, higher levels of shed LDLR were measured in the plasma of women treated with PCSK9 mAb. PCSK9 knockout female mice hormonally sustain cholesterol synthesis and shed excess LDLR, seemingly like women. In contrast, male mice rely on high surface LDLR to replenish their stocks, despite 80 % lower circulating LDL.
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14
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Zhang C, Xiang D, Zhao Q, Jiang S, Wang C, Yang H, Huang Y, Yuan Y, Liu X, Huang Z, Zeng Y, Wen H, Long S, Hao H, Tuo Q, Liu Z, Liao D. Curcumin nicotinate decreases serum LDL cholesterol through LDL receptor-mediated mechanism. Eur J Pharmacol 2022; 931:175195. [PMID: 35964656 DOI: 10.1016/j.ejphar.2022.175195] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Revised: 07/23/2022] [Accepted: 08/05/2022] [Indexed: 11/03/2022]
Abstract
Curcumin nicotinate (Curtn) is a synthesized ester derivative of curcumin and niacin. Our previous study has shown that Curtn lowers serum low-density lipoprotein cholesterol (LDL-C) levels in apoE-/- mice and promotes LDL-C uptake into HepG2 cells in vitro. The present study was to test the hypothesis that Curtn decreases serum LDL-C levels through decreased expression of pro-protein convertase subtilisin/kexin type 9 (PCSK9) and subsequent increase in LDL receptor expression. Male Wistar rats on high-fat diet (HFD) were treated with Curtn or rosuvastatin. Curtn or rosuvastatin treatment significantly decreased serum levels of total cholesterol (TC) and LDL-C in rats on HFD with increased liver LDL receptor expression. LDL-C-lowering effect of Curtn was not observed in LDL receptor deficient (LDLR-/-) mice on HFD, while rosuvastatin still decreased serum lipid levels in LDLR-/- mice, indicating that the reduction of serum LDL-C levels by Curtn treatment was LDL receptor-dependent. Curtn treatment also significantly decreased the protein expression of PCSK9 in Wistar rats and LDLR-/- mice. In HepG2 cells with overexpression of human PCSK9, Curtn treatment significantly increased LDL-C uptakes into hepatocytes, and increased LDL receptor distribution on cell surface in association with decreased PCSK9 protein expression. RNAi-LDLR significantly attenuated the effect of Curtn on LDLR distribution on cell surface. These data indicates that Curtn would decrease serum LDL-C level at least partially through inhibition of PCSK9 expression, and subsequent increase in LDL receptor expression and distribution in hepatocytes, serving as a potential novel compound to treat hyperlipidemia.
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Affiliation(s)
- Caiping Zhang
- Department of Biochemistry & Molecular Biology, Hengyang Medical School, University of South China, Hengyang, Hunan, China; Center for Precision Medicine and Division of Cardiovascular Medicine, Department of Medicine, University of Missouri School of Medicine, Columbia, MO, USA
| | - Debiao Xiang
- Division of Stem Cell Regulation and Application, Hunan University of Chinese Medicine, Changsha, China; Department of Pharmacy, The Third Hospital of Changsha, Changsha, China
| | - Qian Zhao
- Department of Biochemistry & Molecular Biology, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Susu Jiang
- Department of Biochemistry & Molecular Biology, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Chuyao Wang
- Department of Biochemistry & Molecular Biology, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Huixian Yang
- Department of Biochemistry & Molecular Biology, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Ying Huang
- Division of Stem Cell Regulation and Application, Hunan University of Chinese Medicine, Changsha, China
| | - Yulin Yuan
- Department of Biochemistry & Molecular Biology, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Xuanyou Liu
- Center for Precision Medicine and Division of Cardiovascular Medicine, Department of Medicine, University of Missouri School of Medicine, Columbia, MO, USA
| | - Zhixin Huang
- Center for Precision Medicine and Division of Cardiovascular Medicine, Department of Medicine, University of Missouri School of Medicine, Columbia, MO, USA
| | - Yaling Zeng
- Division of Stem Cell Regulation and Application, Hunan University of Chinese Medicine, Changsha, China
| | - Hongyan Wen
- Division of Stem Cell Regulation and Application, Hunan University of Chinese Medicine, Changsha, China
| | - Shiyin Long
- Department of Biochemistry & Molecular Biology, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Hong Hao
- Center for Precision Medicine and Division of Cardiovascular Medicine, Department of Medicine, University of Missouri School of Medicine, Columbia, MO, USA
| | - Qinhui Tuo
- Division of Stem Cell Regulation and Application, Hunan University of Chinese Medicine, Changsha, China
| | - Zhenguo Liu
- Center for Precision Medicine and Division of Cardiovascular Medicine, Department of Medicine, University of Missouri School of Medicine, Columbia, MO, USA.
| | - Duanfang Liao
- Division of Stem Cell Regulation and Application, Hunan University of Chinese Medicine, Changsha, China.
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15
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Regulation of low-density lipoprotein receptor expression in triple negative breast cancer by EGFR-MAPK signaling. Sci Rep 2021; 11:17927. [PMID: 34504181 PMCID: PMC8429745 DOI: 10.1038/s41598-021-97327-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 08/24/2021] [Indexed: 11/15/2022] Open
Abstract
Expression of the low-density lipoprotein receptor (LDLR) has been shown to play a critical role in hypercholesterolemia-associated breast cancer growth and is associated with shorter recurrence-free survival in human breast cancer studies. We sought to identify how circulating LDL cholesterol and tumor LDLR might accelerate oncogenic processes by determining whether increased LDLR expression and cholesterol uptake are associated with the activation of the epidermal growth factor receptor (EGFR) signaling pathway in triple negative breast cancer (TNBC) cell lines. EGF stimulation of MDA-MB-468 (MDA468) cells activated p44/42MAPK (MAPK), increased expression of LDLR, and fluorescent LDL cholesterol uptake. However, stimulation of MDA-MB-231 (MDA231) cells with EGF did not lead to increased expression of LDLR despite inducing phosphorylation of EGFR. Inhibition of MAPK using UO126 in MDA231 cells reduced LDLR expression, and in MDA468 cells, UO126 impaired the LDLR increase in response to EGF. MDA468 cells exposed to the transcription inhibitor, Actinomycin, prior to treatment with EGF showed reduced degradation of LDLR mRNA compared to vehicle-treated cells. Our results suggest that the EGF-associated increase in LDLR protein expression is cell line-specific. The common pathway regulating LDLR expression was MAPK in both TNBC cell lines.
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16
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Li H, Yu XH, Ou X, Ouyang XP, Tang CK. Hepatic cholesterol transport and its role in non-alcoholic fatty liver disease and atherosclerosis. Prog Lipid Res 2021; 83:101109. [PMID: 34097928 DOI: 10.1016/j.plipres.2021.101109] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 05/31/2021] [Accepted: 06/02/2021] [Indexed: 12/12/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is a quickly emerging global health problem representing the most common chronic liver disease in the world. Atherosclerotic cardiovascular disease represents the leading cause of mortality in NAFLD patients. Cholesterol metabolism has a crucial role in the pathogenesis of both NAFLD and atherosclerosis. The liver is the major organ for cholesterol metabolism. Abnormal hepatic cholesterol metabolism not only leads to NAFLD but also drives the development of atherosclerotic dyslipidemia. The cholesterol level in hepatocytes reflects the dynamic balance between endogenous synthesis, uptake, esterification, and export, a process in which cholesterol is converted to neutral cholesteryl esters either for storage in cytosolic lipid droplets or for secretion as a major constituent of plasma lipoproteins, including very-low-density lipoproteins, chylomicrons, high-density lipoproteins, and low-density lipoproteins. In this review, we describe decades of research aimed at identifying key molecules and cellular players involved in each main aspect of hepatic cholesterol metabolism. Furthermore, we summarize the recent advances regarding the biological processes of hepatic cholesterol transport and its role in NAFLD and atherosclerosis.
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Affiliation(s)
- Heng Li
- Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, Hunan International Scientific and Technological Cooperation Base of Arteriosclerotic Disease, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, University of South China, Hengyang, Hunan 421001, China
| | - Xiao-Hua Yu
- Institute of Clinical Medicine, The Second Affiliated Hospital of Hainan Medical University, Haikou, Hainan 460106, China
| | - Xiang Ou
- Department of Endocrinology, the First Hospital of Changsha, Changsha, Hunan 410005, China
| | - Xin-Ping Ouyang
- Department of Physiology, Institute of Neuroscience Research, Hengyang Key Laboratory of Neurodegeneration and Cognitive Impairment, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, University of South China, Hengyang, Hunan 421001, China.
| | - Chao-Ke Tang
- Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, Hunan International Scientific and Technological Cooperation Base of Arteriosclerotic Disease, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, University of South China, Hengyang, Hunan 421001, China.
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17
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Inducible degrader of LDLR: A potential novel therapeutic target and emerging treatment for hyperlipidemia. Vascul Pharmacol 2021; 140:106878. [PMID: 34015522 DOI: 10.1016/j.vph.2021.106878] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 05/10/2021] [Accepted: 05/14/2021] [Indexed: 11/20/2022]
Abstract
Statins are the most effective lipid-lowering drugs ever developed, and numerous patients with cardiovascular disease (CVD) have obtained remarkable benefits from statin therapy. However, issues with statin resistance and intolerance cannot be ignored in clinical practice. Additionally, adverse effects, such as an increased risk of new-onset diabetes and muscle symptoms, may limit the utilization of statins. Therefore, the development of new lipid-lowering agents is necessary to reduce CVD risk in patients who are unable to receive statin therapy. Among these new lipid-lowering strategies, inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9) is an effective way to enhance clearance of LDL-C from the circulation by impeding the degradation of LDL receptor (LDLR) in hepatocytes. Interestingly, given that upregulation of LDLR is an effective method for lowering lipid levels, the question arises as to whether other LDLR-mediated genes could serve as potential therapeutic targets for CVD. As an E3-ubiquitin ligase, inducible degrader of LDLR (IDOL) can cause ubiquitination and degradation of LDLR in lysosome and is a novel regulator of LDLR expression similar to PCSK9. Although there are no approved drugs for targeting the IDOL-LDLR pathway, recent studies demonstrate that IDOL could serve as a potential therapeutic target for hyperlipidemia. Herein, we have summarized these novel studies to present the pathological role of IDOL in CVD, further assessing its pharmacological effects for lipid-lowering therapy.
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18
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Hepatitis C Virus Uses Host Lipids to Its Own Advantage. Metabolites 2021; 11:metabo11050273. [PMID: 33925362 PMCID: PMC8145847 DOI: 10.3390/metabo11050273] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 04/11/2021] [Accepted: 04/23/2021] [Indexed: 02/06/2023] Open
Abstract
Lipids and lipoproteins constitute indispensable components for living not only for humans. In the case of hepatitis C virus (HCV), the option of using the products of our lipid metabolism is “to be, or not to be”. On the other hand, HCV infection, which is the main cause of chronic hepatitis, cirrhosis and hepatocellular carcinoma, exerts a profound influence on lipid and lipoprotein metabolism of the host. The consequences of this alternation are frequently observed as hypolipidemia and hepatic steatosis in chronic hepatitis C (CHC) patients. The clinical relevance of these changes reflects the fact that lipids and lipoprotein play a crucial role in all steps of the life cycle of HCV. The virus circulates in the bloodstream as a highly lipidated lipo-viral particle (LVP) that defines HCV hepatotropism. Thus, strict relationships between lipids/lipoproteins and HCV are indispensable for the mechanism of viral entry into hepatocytes, viral replication, viral particles assembly and secretion. The purpose of this review is to summarize the tricks thanks to which HCV utilizes host lipid metabolism to its own advantage.
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19
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Wang JQ, Lin ZC, Li LL, Zhang SF, Li WH, Liu W, Song BL, Luo J. SUMOylation of the ubiquitin ligase IDOL decreases LDL receptor levels and is reversed by SENP1. J Biol Chem 2020; 296:100032. [PMID: 33154164 PMCID: PMC7948399 DOI: 10.1074/jbc.ra120.015420] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 11/01/2020] [Accepted: 11/05/2020] [Indexed: 11/30/2022] Open
Abstract
Inducible degrader of the low-density lipoprotein receptor (IDOL) is an E3 ubiquitin ligase mediating degradation of low-density lipoprotein (LDL) receptor (LDLR). IDOL also controls its own stability through autoubiquitination, primarily at lysine 293. Whether IDOL may undergo other forms of posttranslational modification is unknown. In this study, we show that IDOL can be modified by small ubiquitin-like modifier 1 at the K293 residue at least. The SUMOylation of IDOL counteracts its ubiquitination and augments IDOL protein levels. SUMOylation and the associated increase of IDOL protein are effectively reversed by SUMO-specific peptidase 1 (SENP1) in an activity-dependent manner. We further demonstrate that SENP1 affects LDLR protein levels by modulating IDOL. Overexpression of SENP1 increases LDLR protein levels and enhances LDL uptake in cultured cells. On the contrary, loss of SENP1 lowers LDLR levels in an IDOL-dependent manner and reduces LDL endocytosis. Collectively, our results reveal SUMOylation as a new regulatory posttranslational modification of IDOL and suggest that SENP1 positively regulates the LDLR pathway via deSUMOylation of IDOL and may therefore be exploited for the treatment of cardiovascular disease.
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Affiliation(s)
- Ju-Qiong Wang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Zi-Cun Lin
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Liang-Liang Li
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Shao-Fang Zhang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Wei-Hui Li
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Wei Liu
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Bao-Liang Song
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Jie Luo
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China.
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20
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Zhao J, Ding Y, He R, Huang K, Liu L, Jiang C, Liu Z, Wang Y, Yan X, Cao F, Huang X, Peng Y, Ren R, He Y, Cui T, Zhang Q, Zhang X, Liu Q, Li Y, Ma Z, Yi X. Dose-effect relationship and molecular mechanism by which BMSC-derived exosomes promote peripheral nerve regeneration after crush injury. Stem Cell Res Ther 2020; 11:360. [PMID: 32811548 PMCID: PMC7437056 DOI: 10.1186/s13287-020-01872-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 07/28/2020] [Accepted: 08/03/2020] [Indexed: 12/13/2022] Open
Abstract
Background The development of new treatment strategies to improve peripheral nerve repair after injury, especially those that accelerate axonal nerve regeneration, is very important. The aim of this study is to elucidate the molecular mechanisms of how bone marrow stromal cell (BMSC)-derived exosomes (EXOs) participate in peripheral nerve regeneration and whether the regenerative effect of EXOs is correlated with dose. Method BMSCs were transfected with or without an siRNA targeting Ago2 (SiAgo2). EXOs extracted from the BMSCs were administered to dorsal root ganglion (DRG) neurons in vitro. After 48 h of culture, the neurite length was measured. Moreover, EXOs at four different doses were injected into the gastrocnemius muscles of rats with sciatic nerve crush injury. The sciatic nerve functional index (SFI) and latency of thermal pain (LTP) of the hind leg sciatic nerve were measured before the operation and at 7, 14, 21, and 28 days after the operation. Then, the number and diameter of the regenerated fibers in the injured distal sciatic nerve were quantified. Seven genes associated with nerve regeneration were investigated by qRT-PCR in DRG neurons extracted from rats 7 days after the sciatic nerve crush. Results We showed that after 48 h of culture, the mean number of neurites and the length of cultured DRG neurons in the SiAgo2-BMSC-EXO and SiAgo2-BMSC groups were smaller than that in the untreated and siRNA control groups. The average number and diameter of regenerated axons, LTP, and SFI in the group with 0.9 × 1010 particles/ml EXOs were better than those in other groups, while the group that received a minimum EXO dose (0.4 × 1010 particles/ml) was not significantly different from the PBS group. The expression of PMP22, VEGFA, NGFr, and S100b in DRGs from the EXO-treated group was significantly higher than that in the PBS control group. No significant difference was observed in the expression of HGF and Akt1 among the groups. Conclusions These results showed that BMSC-derived EXOs can promote the regeneration of peripheral nerves and that the mechanism may involve miRNA-mediated regulation of regeneration-related genes, such as VEGFA. Finally, a dose-effect relationship between EXO treatment and nerve regeneration was shown.
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Affiliation(s)
- Jiuhong Zhao
- Key Laboratory of Brain Science Research & Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou, China.,Department of Anatomy, Hainan Medical University, Haikou, China
| | - Yali Ding
- School of Medicine, Tibet University, Lhasa, China
| | - Rui He
- Department of Anatomy, Hainan Medical University, Haikou, China.,Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
| | - Kui Huang
- Key Laboratory of Brain Science Research & Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou, China
| | - Lu Liu
- Key Laboratory of Brain Science Research & Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou, China
| | - Chaona Jiang
- Key Laboratory of Brain Science Research & Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou, China
| | - Zhuozhou Liu
- Key Laboratory of Brain Science Research & Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou, China
| | - Yuanlan Wang
- Key Laboratory of Brain Science Research & Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou, China
| | - Xiaokai Yan
- Key Laboratory of Brain Science Research & Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou, China
| | - Fuyang Cao
- Key Laboratory of Brain Science Research & Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou, China
| | - Xueying Huang
- Key Laboratory of Brain Science Research & Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou, China
| | - Yanan Peng
- Key Laboratory of Brain Science Research & Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou, China.,Department of Anatomy, Hainan Medical University, Haikou, China
| | - Rui Ren
- Key Laboratory of Brain Science Research & Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou, China.,Department of Anatomy, Hainan Medical University, Haikou, China
| | - Yuebin He
- Key Laboratory of Brain Science Research & Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou, China.,Department of Anatomy, Hainan Medical University, Haikou, China
| | - Tianwei Cui
- Key Laboratory of Brain Science Research & Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou, China.,Department of Anatomy, Hainan Medical University, Haikou, China
| | - Quanpeng Zhang
- Key Laboratory of Brain Science Research & Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou, China.,Department of Anatomy, Hainan Medical University, Haikou, China
| | - Xianfang Zhang
- Key Laboratory of Brain Science Research & Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou, China.,Department of Anatomy, Hainan Medical University, Haikou, China
| | - Qibing Liu
- Department of Anatomy, Hainan Medical University, Haikou, China
| | - Yunqing Li
- Department of Anatomy, Hainan Medical University, Haikou, China
| | - Zhijian Ma
- Key Laboratory of Brain Science Research & Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou, China. .,Department of Anatomy, Hainan Medical University, Haikou, China.
| | - Xinan Yi
- Key Laboratory of Brain Science Research & Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou, China. .,Department of Anatomy, Hainan Medical University, Haikou, China.
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21
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Martinelli L, Adamopoulos A, Johansson P, Wan PT, Gunnarsson J, Guo H, Boyd H, Zelcer N, Sixma TK. Structural analysis of the LDL receptor-interacting FERM domain in the E3 ubiquitin ligase IDOL reveals an obscured substrate-binding site. J Biol Chem 2020; 295:13570-13583. [PMID: 32727844 PMCID: PMC7521653 DOI: 10.1074/jbc.ra120.014349] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 07/21/2020] [Indexed: 12/31/2022] Open
Abstract
Hepatic abundance of the low-density lipoprotein receptor (LDLR) is a critical determinant of circulating plasma LDL cholesterol levels and hence development of coronary artery disease. The sterol-responsive E3 ubiquitin ligase inducible degrader of the LDLR (IDOL) specifically promotes ubiquitination and subsequent lysosomal degradation of the LDLR and thus controls cellular LDL uptake. IDOL contains an extended N-terminal FERM (4.1 protein, ezrin, radixin, and moesin) domain, responsible for substrate recognition and plasma membrane association, and a second C-terminal RING domain, responsible for the E3 ligase activity and homodimerization. As IDOL is a putative lipid-lowering drug target, we investigated the molecular details of its substrate recognition. We produced and isolated full-length IDOL protein, which displayed high autoubiquitination activity. However, in vitro ubiquitination of its substrate, the intracellular tail of the LDLR, was low. To investigate the structural basis for this, we determined crystal structures of the extended FERM domain of IDOL and multiple conformations of its F3ab subdomain. These reveal the archetypal F1-F2-F3 trilobed FERM domain structure but show that the F3c subdomain orientation obscures the target-binding site. To substantiate this finding, we analyzed the full-length FERM domain and a series of truncated FERM constructs by small-angle X-ray scattering (SAXS). The scattering data support a compact and globular core FERM domain with a more flexible and extended C-terminal region. This flexibility may explain the low activity in vitro and suggests that IDOL may require activation for recognition of the LDLR.
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Affiliation(s)
- Luca Martinelli
- Division of Biochemistry, Netherlands Cancer Institute, Amsterdam, The Netherlands; Department of Medical Biochemistry, Amsterdam UMC, Amsterdam Cardiovascular Sciences and Gastroenterology and Metabolism, University of Amsterdam, Amsterdam, the Netherlands
| | | | - Patrik Johansson
- IMED Biotech Unit, Discovery Sciences, AstraZeneca, Mölndal, Sweden
| | - Paul T Wan
- IMED Biotech Unit, Discovery Sciences, AstraZeneca, Mölndal, Sweden
| | - Jenny Gunnarsson
- IMED Biotech Unit, Discovery Sciences, AstraZeneca, Mölndal, Sweden
| | - Hongwei Guo
- IMED Biotech Unit, Discovery Sciences, AstraZeneca, Mölndal, Sweden
| | - Helen Boyd
- IMED Biotech Unit, Discovery Sciences, AstraZeneca, Mölndal, Sweden
| | - Noam Zelcer
- Department of Medical Biochemistry, Amsterdam UMC, Amsterdam Cardiovascular Sciences and Gastroenterology and Metabolism, University of Amsterdam, Amsterdam, the Netherlands.
| | - Titia K Sixma
- Division of Biochemistry, Netherlands Cancer Institute, Amsterdam, The Netherlands; Oncode Institute, Utrecht, The Netherlands.
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22
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van den Boomen DJH, Volkmar N, Lehner PJ. Ubiquitin-mediated regulation of sterol homeostasis. Curr Opin Cell Biol 2020; 65:103-111. [PMID: 32580085 DOI: 10.1016/j.ceb.2020.04.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 04/03/2020] [Accepted: 04/26/2020] [Indexed: 11/19/2022]
Abstract
Cholesterol is an essential component of mammalian membranes, and its homeostasis is strictly regulated, with imbalances causing atherosclerosis, Niemann Pick disease, and familial hypercholesterolemia. Cellular cholesterol supply is mediated by LDL-cholesterol import and de novo cholesterol biosynthesis, and both pathways are adjusted to cellular demand by the cholesterol-sensitive SREBP2 transcription factor. Cholesterol homeostasis is modulated by a wide variety of metabolic pathways and the ubiquitination machinery, in particular E3 ubiquitin ligases. In this article, we review recent progress in understanding the role of E3 ubiquitin ligases in the metabolic control of cellular sterol homeostasis.
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Affiliation(s)
- Dick J H van den Boomen
- Cambridge Institute of Therapeutic Immunology & Infectious Disease, University of Cambridge, Cambridge, United Kingdom
| | - Norbert Volkmar
- Cambridge Institute of Therapeutic Immunology & Infectious Disease, University of Cambridge, Cambridge, United Kingdom
| | - Paul J Lehner
- Cambridge Institute of Therapeutic Immunology & Infectious Disease, University of Cambridge, Cambridge, United Kingdom.
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23
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Salerno AG, van Solingen C, Scotti E, Wanschel ACBA, Afonso MS, Oldebeken SR, Spiro W, Tontonoz P, Rayner KJ, Moore KJ. LDL Receptor Pathway Regulation by miR-224 and miR-520d. Front Cardiovasc Med 2020; 7:81. [PMID: 32528976 PMCID: PMC7256473 DOI: 10.3389/fcvm.2020.00081] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 04/15/2020] [Indexed: 12/27/2022] Open
Abstract
MicroRNAs (miRNA) have emerged as important post-transcriptional regulators of metabolic pathways that contribute to cellular and systemic lipoprotein homeostasis. Here, we identify two conserved miRNAs, miR-224, and miR-520d, which target gene networks regulating hepatic expression of the low-density lipoprotein (LDL) receptor (LDLR) and LDL clearance. In silico prediction of miR-224 and miR-520d target gene networks showed that they each repress multiple genes impacting the expression of the LDLR, including the chaperone molecules PCSK9 and IDOL that limit LDLR expression at the cell surface and the rate-limiting enzyme for cholesterol synthesis HMGCR, which is the target of LDL-lowering statin drugs. Using gain- and loss-of-function studies, we tested the role of miR-224 and miR-520d in the regulation of those predicted targets and their impact on LDLR expression. We show that overexpression of miR-224 or miR-520d dose-dependently reduced the activity of PCSK9, IDOL, and HMGCR 3'-untranslated region (3'-UTR)-luciferase reporter constructs and that this repression was abrogated by mutation of the putative miR-224 or miR-520d response elements in the PCSK9, IDOL, and HMGCR 3'-UTRs. Compared to a control miRNA, overexpression of miR-224 or miR-520d in hepatocytes inhibited PCSK9, IDOL, and HMGCR mRNA and protein levels and decreased PCSK9 secretion. Furthermore, miR-224 and miR-520d repression of PCSK9, IDOL, and HMGCR was associated with an increase in LDLR protein levels and cell surface expression, as well as enhanced LDL binding. Notably, the effects of miR-224 and miR-520d were additive to the effects of statins in upregulating LDLR expression. Finally, we show that overexpression of miR-224 in the livers of Ldlr +/- mice using lipid nanoparticle-mediated delivery resulted in a 15% decrease in plasma levels of LDL cholesterol, compared to a control miRNA. Together, these findings identify roles for miR-224 and miR-520d in the posttranscriptional control of LDLR expression and function.
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Affiliation(s)
- Alessandro G Salerno
- Leon H. Charney Division of Cardiology, NYU Cardiovascular Research Center, Department of Medicine, New York University School of Medicine, New York, NY, United States
| | - Coen van Solingen
- Leon H. Charney Division of Cardiology, NYU Cardiovascular Research Center, Department of Medicine, New York University School of Medicine, New York, NY, United States
| | - Elena Scotti
- Howard Hughes Medical Institute and Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Amarylis C B A Wanschel
- Leon H. Charney Division of Cardiology, NYU Cardiovascular Research Center, Department of Medicine, New York University School of Medicine, New York, NY, United States
| | - Milessa S Afonso
- Leon H. Charney Division of Cardiology, NYU Cardiovascular Research Center, Department of Medicine, New York University School of Medicine, New York, NY, United States
| | - Scott R Oldebeken
- Leon H. Charney Division of Cardiology, NYU Cardiovascular Research Center, Department of Medicine, New York University School of Medicine, New York, NY, United States
| | - Westley Spiro
- Leon H. Charney Division of Cardiology, NYU Cardiovascular Research Center, Department of Medicine, New York University School of Medicine, New York, NY, United States
| | - Peter Tontonoz
- Howard Hughes Medical Institute and Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Katey J Rayner
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - Kathryn J Moore
- Leon H. Charney Division of Cardiology, NYU Cardiovascular Research Center, Department of Medicine, New York University School of Medicine, New York, NY, United States.,Department of Cell Biology, New York University School of Medicine, New York, NY, United States
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24
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Ubiquitin-specific protease 8 (USP8/UBPy): a prototypic multidomain deubiquitinating enzyme with pleiotropic functions. Biochem Soc Trans 2020; 47:1867-1879. [PMID: 31845722 PMCID: PMC6925526 DOI: 10.1042/bst20190527] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 11/29/2019] [Accepted: 12/02/2019] [Indexed: 01/07/2023]
Abstract
Protein modification by ubiquitin is one of the most versatile posttranslational regulations and counteracted by almost 100 deubiquitinating enzymes (DUBs). USP8 was originally identified as a growth regulated ubiquitin-specific protease and is like many other DUBs characterized by its multidomain architecture. Besides the catalytic domain, specific protein-protein interaction modules were characterized which contribute to USP8 substrate recruitment, regulation and targeting to distinct protein complexes. Studies in mice and humans impressively showed the physiological relevance and non-redundant function of USP8 within the context of the whole organism. USP8 knockout (KO) mice exhibit early embryonic lethality while induced deletion in adult animals rapidly causes lethal liver failure. Furthermore, T-cell specific ablation disturbs T-cell development and function resulting in fatal autoimmune inflammatory bowel disease. In human patients, somatic mutations in USP8 were identified as the underlying cause of adrenocorticotropic hormone (ACTH) releasing pituitary adenomas causing Cushing's disease (CD). Here we provide an overview of the versatile molecular, cellular and pathology associated function and regulation of USP8 which appears to depend on specific protein binding partners, substrates and the cellular context.
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25
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Mechanisms and regulation of cholesterol homeostasis. Nat Rev Mol Cell Biol 2019; 21:225-245. [DOI: 10.1038/s41580-019-0190-7] [Citation(s) in RCA: 450] [Impact Index Per Article: 90.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/24/2019] [Indexed: 12/14/2022]
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26
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Brophy ML, Dong Y, Tao H, Yancey PG, Song K, Zhang K, Wen A, Wu H, Lee Y, Malovichko MV, Sithu SD, Wong S, Yu L, Kocher O, Bischoff J, Srivastava S, Linton MF, Ley K, Chen H. Myeloid-Specific Deletion of Epsins 1 and 2 Reduces Atherosclerosis by Preventing LRP-1 Downregulation. Circ Res 2019; 124:e6-e19. [PMID: 30595089 DOI: 10.1161/circresaha.118.313028] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
RATIONALE Atherosclerosis is, in part, caused by immune and inflammatory cell infiltration into the vascular wall, leading to enhanced inflammation and lipid accumulation in the aortic endothelium. Understanding the molecular mechanisms underlying this disease is critical for the development of new therapies. Our recent studies demonstrate that epsins, a family of ubiquitin-binding endocytic adaptors, are critical regulators of atherogenicity. Given the fundamental contribution lesion macrophages make to fuel atherosclerosis, whether and how myeloid-specific epsins promote atherogenesis is an open and significant question. OBJECTIVE We will determine the role of myeloid-specific epsins in regulating lesion macrophage function during atherosclerosis. METHODS AND RESULTS We engineered myeloid cell-specific epsins double knockout mice (LysM-DKO) on an ApoE-/- background. On Western diet, these mice exhibited marked decrease in atherosclerotic lesion formation, diminished immune and inflammatory cell content in aortas, and reduced necrotic core content but increased smooth muscle cell content in aortic root sections. Epsins deficiency hindered foam cell formation and suppressed proinflammatory macrophage phenotype but increased efferocytosis and anti-inflammatory macrophage phenotype in primary macrophages. Mechanistically, we show that epsin loss specifically increased total and surface levels of LRP-1 (LDLR [low-density lipoprotein receptor]-related protein 1), an efferocytosis receptor with antiatherosclerotic properties. We further show that epsin and LRP-1 interact via epsin's ubiquitin-interacting motif domain. ox-LDL (oxidized LDL) treatment increased LRP-1 ubiquitination, subsequent binding to epsin, and its internalization from the cell surface, suggesting that epsins promote the ubiquitin-dependent internalization and downregulation of LRP-1. Crossing ApoE-/-/LysM-DKO mice onto an LRP-1 heterozygous background restored, in part, atherosclerosis, suggesting that epsin-mediated LRP-1 downregulation in macrophages plays a pivotal role in propelling atherogenesis. CONCLUSIONS Myeloid epsins promote atherogenesis by facilitating proinflammatory macrophage recruitment and inhibiting efferocytosis in part by downregulating LRP-1, implicating that targeting epsins in macrophages may serve as a novel therapeutic strategy to treat atherosclerosis.
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Affiliation(s)
- Megan L Brophy
- From the Vascular Biology Program and Department of Surgery, Boston Children's Hospital (M.L.B., Y.D., K.S., K.Z., A.W., H.W., Y.L., S.W., L.Y., J.B., H.C.), Harvard Medical School, MA.,Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center (M.L.B.)
| | - Yunzhou Dong
- From the Vascular Biology Program and Department of Surgery, Boston Children's Hospital (M.L.B., Y.D., K.S., K.Z., A.W., H.W., Y.L., S.W., L.Y., J.B., H.C.), Harvard Medical School, MA
| | - Huan Tao
- Atherosclerosis Research Unit, Cardiovascular Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN (H.T., P.G.Y., M.F.L.)
| | - Patricia G Yancey
- Atherosclerosis Research Unit, Cardiovascular Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN (H.T., P.G.Y., M.F.L.)
| | - Kai Song
- From the Vascular Biology Program and Department of Surgery, Boston Children's Hospital (M.L.B., Y.D., K.S., K.Z., A.W., H.W., Y.L., S.W., L.Y., J.B., H.C.), Harvard Medical School, MA
| | - Kun Zhang
- From the Vascular Biology Program and Department of Surgery, Boston Children's Hospital (M.L.B., Y.D., K.S., K.Z., A.W., H.W., Y.L., S.W., L.Y., J.B., H.C.), Harvard Medical School, MA.,Department of Cardiology, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou, China (K.Z.)
| | - Aiyun Wen
- From the Vascular Biology Program and Department of Surgery, Boston Children's Hospital (M.L.B., Y.D., K.S., K.Z., A.W., H.W., Y.L., S.W., L.Y., J.B., H.C.), Harvard Medical School, MA
| | - Hao Wu
- From the Vascular Biology Program and Department of Surgery, Boston Children's Hospital (M.L.B., Y.D., K.S., K.Z., A.W., H.W., Y.L., S.W., L.Y., J.B., H.C.), Harvard Medical School, MA
| | - Yang Lee
- From the Vascular Biology Program and Department of Surgery, Boston Children's Hospital (M.L.B., Y.D., K.S., K.Z., A.W., H.W., Y.L., S.W., L.Y., J.B., H.C.), Harvard Medical School, MA
| | - Marina V Malovichko
- Division of Cardiovascular Medicine, Department of Medicine, University of Louisville, KY (M.V.M., S.D.S., S.S.)
| | - Srinivas D Sithu
- Division of Cardiovascular Medicine, Department of Medicine, University of Louisville, KY (M.V.M., S.D.S., S.S.)
| | - Scott Wong
- From the Vascular Biology Program and Department of Surgery, Boston Children's Hospital (M.L.B., Y.D., K.S., K.Z., A.W., H.W., Y.L., S.W., L.Y., J.B., H.C.), Harvard Medical School, MA
| | - Lili Yu
- From the Vascular Biology Program and Department of Surgery, Boston Children's Hospital (M.L.B., Y.D., K.S., K.Z., A.W., H.W., Y.L., S.W., L.Y., J.B., H.C.), Harvard Medical School, MA
| | - Olivier Kocher
- Department of Pathology and Center for Vascular Biology Research, Beth Israel Medical Deaconess Medical Center (O.K.), Harvard Medical School, MA
| | - Joyce Bischoff
- From the Vascular Biology Program and Department of Surgery, Boston Children's Hospital (M.L.B., Y.D., K.S., K.Z., A.W., H.W., Y.L., S.W., L.Y., J.B., H.C.), Harvard Medical School, MA
| | - Sanjay Srivastava
- Division of Cardiovascular Medicine, Department of Medicine, University of Louisville, KY (M.V.M., S.D.S., S.S.)
| | - MacRae F Linton
- Atherosclerosis Research Unit, Cardiovascular Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN (H.T., P.G.Y., M.F.L.)
| | - Klaus Ley
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, CA (K.L.)
| | - Hong Chen
- From the Vascular Biology Program and Department of Surgery, Boston Children's Hospital (M.L.B., Y.D., K.S., K.Z., A.W., H.W., Y.L., S.W., L.Y., J.B., H.C.), Harvard Medical School, MA
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27
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Yang HX, Zhang M, Long SY, Tuo QH, Tian Y, Chen JX, Zhang CP, Liao DF. Cholesterol in LDL receptor recycling and degradation. Clin Chim Acta 2019; 500:81-86. [PMID: 31770510 DOI: 10.1016/j.cca.2019.09.022] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 09/18/2019] [Accepted: 09/18/2019] [Indexed: 11/26/2022]
Abstract
The SREBP2/LDLR pathway is sensitive to cholesterol content in the endoplasmic reticulum (ER), while membrane low-density lipoprotein receptor (LDLR) is influenced by sterol response element binding protein 2 (SREBP2), pro-protein convertase subtilisin/kexin type 9 (PCSK9) and inducible degrader of LDLR (IDOL). LDL-C, one of the risk factors in cardiovascular disease, is cleared through endocytosis recycling of LDLR. Therefore, we propose that a balance between LDLR endocytosis recycling and PCSK9-mediated and IDOL-mediated lysosomal LDLR degradation is responsible for cholesterol homeostasis in the ER. For statins that decrease serum LDL-C levels via cholesterol synthesis inhibition, the mechanism by which the statins increase the membrane LDLR may be regulated by cholesterol homeostasis in the ER.
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Affiliation(s)
- Hui-Xian Yang
- Institute of Cardiovascular Disease, Medical College, University of South China, 28# W Changsheng Rd, Hengyang 421001, Hunan, China; Department of Biochemistry and Molecular Biology, Medical College, University of South China, 28# W Changsheng Rd, Hengyang 421001, Hunan, China
| | - Min Zhang
- Department of Biochemistry and Molecular Biology, Medical College, University of South China, 28# W Changsheng Rd, Hengyang 421001, Hunan, China
| | - Shi-Yin Long
- Department of Biochemistry and Molecular Biology, Medical College, University of South China, 28# W Changsheng Rd, Hengyang 421001, Hunan, China
| | - Qin-Hui Tuo
- Division of Stem Cell Regulation and Application, State Key Laboratory of Chinese Medicine Powder and Medicine Innovation in Hunan (incubation), Hunan University of Chinese Medicine, 300# Xueshi Rd., Hanpu Science & Education District, Changsha 410208, Hunan, China
| | - Ying Tian
- Department of Biochemistry and Molecular Biology, Medical College, University of South China, 28# W Changsheng Rd, Hengyang 421001, Hunan, China
| | - Jian-Xiong Chen
- Division of Stem Cell Regulation and Application, State Key Laboratory of Chinese Medicine Powder and Medicine Innovation in Hunan (incubation), Hunan University of Chinese Medicine, 300# Xueshi Rd., Hanpu Science & Education District, Changsha 410208, Hunan, China; Department Pharmacology & Toxicology, University of Mississippi Medical Center, USA
| | - Cai-Ping Zhang
- Department of Biochemistry and Molecular Biology, Medical College, University of South China, 28# W Changsheng Rd, Hengyang 421001, Hunan, China.
| | - Duan-Fang Liao
- Division of Stem Cell Regulation and Application, State Key Laboratory of Chinese Medicine Powder and Medicine Innovation in Hunan (incubation), Hunan University of Chinese Medicine, 300# Xueshi Rd., Hanpu Science & Education District, Changsha 410208, Hunan, China.
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28
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Xia H, Chen L, Shao D, Liu X, Wang Q, Zhu F, Guo Z, Gao L, Chen K. Vacuolar protein sorting 4 is required for silkworm metamorphosis. INSECT MOLECULAR BIOLOGY 2019; 28:728-738. [PMID: 30955208 DOI: 10.1111/imb.12586] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Vacuolar protein sorting 4 (Vps4) not only functions with its positive regulator vacuolar protein sorting 20-associated 1 (Vta1) in the multivesicular body (MVB) pathway but also participates alone in MVB-unrelated cellular processes. However, its physiological roles at the organism level remain rarely explored. We previously identified their respective homologues Bombyx mori Vps4 (BmVps4) and BmVta1 from the silkworm, a model organism for insect research. In this study, we performed fluorescence quantitative real-time PCR and Western blot to globally characterize the transcription and protein expression profiles of BmVps4 and BmVta1 during silkworm development and in different silkworm tissues and organs. The results showed that they were significantly up-regulated in metamorphosis, adulthood and embryogenesis relative to larval stages, and displayed a roughly similar tissue-and-organ specificity for transcriptions in silkworm larvae. Importantly, BmVps4 was down-regulated during the early period of the fifth instar, reaching the lowest level of transcription on Day 6, then up-regulated from Day 7 to the wandering, spinning and pupal stages, and down-regulated again in adulthood. Moreover, knocking down BmVps4 by RNA interference significantly inhibited silk gland growth, shortened spinning time, prolonged pupation, reduced pupal size and weight, and increased moth wing defects. Together, our data demonstrate the critical and broad requirements for BmVps4 in silkworm metamorphosis.
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Affiliation(s)
- H Xia
- Institute of Life Sciences, Jiangsu University, Zhenjiang, China
| | - L Chen
- Institute of Life Sciences, Jiangsu University, Zhenjiang, China
| | - D Shao
- Institute of Life Sciences, Jiangsu University, Zhenjiang, China
| | - X Liu
- Institute of Life Sciences, Jiangsu University, Zhenjiang, China
| | - Q Wang
- Institute of Life Sciences, Jiangsu University, Zhenjiang, China
| | - F Zhu
- Institute of Life Sciences, Jiangsu University, Zhenjiang, China
| | - Z Guo
- Institute of Life Sciences, Jiangsu University, Zhenjiang, China
| | - L Gao
- Institute of Life Sciences, Jiangsu University, Zhenjiang, China
| | - K Chen
- Institute of Life Sciences, Jiangsu University, Zhenjiang, China
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29
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Wijers M, Zanoni P, Liv N, Vos DY, Jäckstein MY, Smit M, Wilbrink S, Wolters JC, van der Veen YT, Huijkman N, Dekker D, Kloosterhuis N, van Dijk TH, Billadeau DD, Kuipers F, Klumperman J, von Eckardstein A, Kuivenhoven JA, van de Sluis B. The hepatic WASH complex is required for efficient plasma LDL and HDL cholesterol clearance. JCI Insight 2019; 4:126462. [PMID: 31167970 DOI: 10.1172/jci.insight.126462] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 04/17/2019] [Indexed: 12/21/2022] Open
Abstract
The evolutionary conserved Wiskott-Aldrich syndrome protein and SCAR homolog (WASH) complex is one of the crucial multiprotein complexes that facilitates endosomal recycling of transmembrane proteins. Defects in WASH components have been associated with inherited developmental and neurological disorders in humans. Here, we show that hepatic ablation of the WASH component Washc1 in chow-fed mice increases plasma concentrations of cholesterol in both LDLs and HDLs, without affecting hepatic cholesterol content, hepatic cholesterol synthesis, biliary cholesterol excretion, or hepatic bile acid metabolism. Elevated plasma LDL cholesterol was related to reduced hepatocytic surface levels of the LDL receptor (LDLR) and the LDLR-related protein LRP1. Hepatic WASH ablation also reduced the surface levels of scavenger receptor class B type I and, concomitantly, selective uptake of HDL cholesterol into the liver. Furthermore, we found that WASHC1 deficiency increases LDLR proteolysis by the inducible degrader of LDLR, but does not affect proprotein convertase subtilisin/kexin type 9-mediated LDLR degradation. Remarkably, however, loss of hepatic WASHC1 may sensitize LDLR for proprotein convertase subtilisin/kexin type 9-induced degradation. Altogether, these findings identify the WASH complex as a regulator of LDL as well as HDL metabolism and provide in vivo evidence for endosomal trafficking of scavenger receptor class B type I in hepatocytes.
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Affiliation(s)
- Melinde Wijers
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Paolo Zanoni
- Institute for Clinical Chemistry, University Hospital Zurich, Zurich, Switzerland; Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Nalan Liv
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Dyonne Y Vos
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Michelle Y Jäckstein
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Marieke Smit
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Sanne Wilbrink
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Justina C Wolters
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Ydwine T van der Veen
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Nicolette Huijkman
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Daphne Dekker
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Niels Kloosterhuis
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Theo H van Dijk
- Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Daniel D Billadeau
- Department of Immunology and Biochemistry, Division of Oncology Research, Mayo Clinic, Rochester, New York, USA
| | - Folkert Kuipers
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, Netherlands.,Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Judith Klumperman
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Arnold von Eckardstein
- Institute for Clinical Chemistry, University Hospital Zurich, Zurich, Switzerland; Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Jan Albert Kuivenhoven
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Bart van de Sluis
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
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30
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van Loon NM, Lindholm D, Zelcer N. The E3 ubiquitin ligase inducible degrader of the LDL receptor/myosin light chain interacting protein in health and disease. Curr Opin Lipidol 2019; 30:192-197. [PMID: 30896554 DOI: 10.1097/mol.0000000000000593] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
PURPOSE OF REVIEW The RING E3 ubiquitin ligase inducible degrader of the LDL receptor (IDOL, also known as MYLIP) promotes ubiquitylation and subsequent lysosomal degradation of the LDL receptor (LDLR), thus acting to limit uptake of lipoprotein-derived cholesterol into cells. Next to the LDLR, IDOL also promotes degradation of two related receptors, the very LDL receptor (VLDLR) and apolipoprotein E receptor 2 (APOER2), which have important signaling functions in the brain. We review here the emerging role of IDOL in lipoprotein and energy metabolism, neurodegenerative diseases, and the potential for therapeutic targeting of IDOL. RECENT FINDINGS Genetic studies suggest an association between IDOL and lipoprotein metabolism in humans. Studies in rodents and nonhuman primates support an in-vivo role for IDOL in lipoprotein metabolism, and also uncovered an unexpected role in whole-body energy metabolism. Recent evaluation of IDOL function in the brain revealed a role in memory formation and progression of Alzheimer's disease. The report of the first IDOL inhibitor may facilitate further investigations on therapeutic strategies to target IDOL. SUMMARY IDOL is emerging as an important determinant of lipid and energy metabolism in metabolic disease as well as in Alzheimer's disease. IDOL targeting may be beneficial in treating these conditions.
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Affiliation(s)
- Nienke M van Loon
- Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, the Netherlands
| | - Dan Lindholm
- Medicum, Department of Biochemistry and Developmental Biology, Medical Faculty, University of Helsinki
- Minerva Foundation Institute for Medical Research, Biomedicum-2, Helsinki, Finland
| | - Noam Zelcer
- Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, the Netherlands
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Mundi S, Massaro M, Scoditti E, Carluccio MA, van Hinsbergh VWM, Iruela-Arispe ML, De Caterina R. Endothelial permeability, LDL deposition, and cardiovascular risk factors-a review. Cardiovasc Res 2019; 114:35-52. [PMID: 29228169 DOI: 10.1093/cvr/cvx226] [Citation(s) in RCA: 192] [Impact Index Per Article: 38.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Accepted: 12/05/2017] [Indexed: 12/21/2022] Open
Abstract
Early atherosclerosis features functional and structural changes in the endothelial barrier function that affect the traffic of molecules and solutes between the vessel lumen and the vascular wall. Such changes are mechanistically related to the development of atherosclerosis. Proatherogenic stimuli and cardiovascular risk factors, such as dyslipidaemias, diabetes, obesity, and smoking, all increase endothelial permeability sharing a common signalling denominator: an imbalance in the production/disposal of reactive oxygen species (ROS), broadly termed oxidative stress. Mostly as a consequence of the activation of enzymatic systems leading to ROS overproduction, proatherogenic factors lead to a pro-inflammatory status that translates in changes in gene expression and functional rearrangements, including changes in the transendothelial transport of molecules, leading to the deposition of low-density lipoproteins (LDL) and the subsequent infiltration of circulating leucocytes in the intima. In this review, we focus on such early changes in atherogenesis and on the concept that proatherogenic stimuli and risk factors for cardiovascular disease, by altering the endothelial barrier properties, co-ordinately trigger the accumulation of LDL in the intima and ultimately plaque formation.
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Affiliation(s)
- Santa Mundi
- Department of Biological and Environmental Science and Technology (DISTEBA), University of Salento, via Monteroni, 73100, Lecce, Italy
| | - Marika Massaro
- National Research Council (CNR), Department of Biomedical sciences, Institute of Clinical Physiology, Via Monteroni, 73100, Lecce, Italy
| | - Egeria Scoditti
- National Research Council (CNR), Department of Biomedical sciences, Institute of Clinical Physiology, Via Monteroni, 73100, Lecce, Italy
| | - Maria Annunziata Carluccio
- National Research Council (CNR), Department of Biomedical sciences, Institute of Clinical Physiology, Via Monteroni, 73100, Lecce, Italy
| | - Victor W M van Hinsbergh
- Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, van der Boechorststraat, NL-1081 BT, Amsterdam, The Netherlands
| | - Marial Luisa Iruela-Arispe
- Department of Molecular, Cell and Developmental Biology and Molecular Biology Institute, University of California, 610 Charles E Young Dr S, 90095, Los Angeles, USA; and
| | - Raffaele De Caterina
- Department of Neuroscience, Imaging and Clinical Science and Institute of Advanced Biomedical Technologies, University G. D'Annunzio, via dei Vestini, 66100 Chieti, Italy
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Ma S, Sun W, Gao L, Liu S. Therapeutic targets of hypercholesterolemia: HMGCR and LDLR. Diabetes Metab Syndr Obes 2019; 12:1543-1553. [PMID: 31686875 PMCID: PMC6709517 DOI: 10.2147/dmso.s219013] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 07/25/2019] [Indexed: 12/14/2022] Open
Abstract
Cholesterol homeostasis is critical and necessary for the body's functions. Hypercholesterolemia can lead to significant clinical problems, such as cardiovascular disease (CVD). 3-Hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) and low-density lipoprotein cholesterol receptor (LDLR) are major points of control in cholesterol homeostasis. We summarize the regulatory mechanisms of HMGCR and LDLR, which may provide insight for new drug design and development.
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Affiliation(s)
- Shizhan Ma
- Department of Endocrinology and Metabolism, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan250021, People’s Republic of China
- Department of Endocrinology and Metabolism, Shandong Provincial Hospital Affiliated to Shandong University, Jinan250021, People’s Republic of China
| | - Wenxiu Sun
- Department of Pharmacy, Taishan Vocational College of Nursing, Taian271000, People’s Republic of China
| | - Ling Gao
- Department of Endocrinology and Metabolism, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan250021, People’s Republic of China
- Scientific Center, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan250021, People’s Republic of China
- Scientific Center, Shandong Provincial Hospital Affiliated to Shandong University, Jinan250021, People’s Republic of China
- Correspondence: Ling GaoScientific Center, Shandong Provincial Hospital Affiliated to Shandong University, 324 Jing 5 Road, Jinan, Shandong Province250021, People’s Republic of ChinaTel +86 531 6877 6910Email
| | - Shudong Liu
- Department of Endocrinology, Shandong Rongjun General Hospital, Jinan250013, People’s Republic of China
- Shudong LiuDepartment of Endocrinology, Shandong Rongjun General Hospital, 23 Jiefang Road, Jinan, Shandong Province250013, People’s Republic of ChinaTel +86 531 8238 2351Email
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van Loon NM, Ottenhoff R, Kooijman S, Moeton M, Scheij S, Roscam Abbing RL, Gijbels MJ, Levels JH, Sorrentino V, Berbée JF, Rensen PC, Zelcer N. Inactivation of the E3 Ubiquitin Ligase IDOL Attenuates Diet-Induced Obesity and Metabolic Dysfunction in Mice. Arterioscler Thromb Vasc Biol 2018; 38:1785-1795. [PMID: 29903737 PMCID: PMC6092113 DOI: 10.1161/atvbaha.118.311168] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 05/31/2018] [Indexed: 12/26/2022]
Abstract
Objective- The E3 ubiquitin ligase IDOL (inducible degrader of the LDLR [LDL (low-density lipoprotein) receptor]) is a post-transcriptional regulator of LDLR abundance. Model systems and human genetics support a role for IDOL in regulating circulating LDL levels. Whether IDOL plays a broader metabolic role and affects development of metabolic syndrome-associated comorbidities is unknown. Approach and Results- We studied WT (wild type) and Idol(-/-) (Idol-KO) mice in 2 models: physiological aging and diet-induced obesity. In both models, deletion of Idol protected mice from metabolic dysfunction. On a Western-type diet, Idol loss resulted in decreased circulating levels of cholesterol, triglycerides, glucose, and insulin. This was accompanied by protection from weight gain in short- and long-term dietary challenges, which could be attributed to reduced hepatosteatosis and fat mass in Idol-KO mice. Although feeding and intestinal fat uptake were unchanged in Idol-KO mice, their brown adipose tissue was protected from lipid accumulation and had elevated expression of UCP1 (uncoupling protein 1) and TH (tyrosine hydroxylase). Indirect calorimetry indicated a marked increase in locomotion and suggested a trend toward increased cumulative energy expenditure and fat oxidation. An increase in in vivo clearance of reconstituted lipoprotein particles in Idol-KO mice may sustain this energetic demand. In the BXD mouse genetic reference population, hepatic Idol expression correlates with multiple metabolic parameters, thus providing support for findings in the Idol-KO mice. Conclusions- Our study uncovers an unrecognized role for Idol in regulation of whole body metabolism in physiological aging and on a Western-type diet. These findings support Idol inhibition as a therapeutic strategy to target multiple metabolic syndrome-associated comorbidities.
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Affiliation(s)
- Nienke M. van Loon
- From the Department of Medical Biochemistry (N.M.v.L., R.O., M.M., S.S., M.J.J.G., N.Z.)
| | - Roelof Ottenhoff
- From the Department of Medical Biochemistry (N.M.v.L., R.O., M.M., S.S., M.J.J.G., N.Z.)
| | - Sander Kooijman
- Academic Medical Center, University of Amsterdam, The Netherlands; Division of Endocrinology, Department of Medicine, Einthoven Laboratory for Experimental Vascular and Regenerative Medicine, Leiden University Medical Center, The Netherlands (S.K., J.F.P.B., P.C.N.R.)
| | - Martina Moeton
- From the Department of Medical Biochemistry (N.M.v.L., R.O., M.M., S.S., M.J.J.G., N.Z.)
| | - Saskia Scheij
- From the Department of Medical Biochemistry (N.M.v.L., R.O., M.M., S.S., M.J.J.G., N.Z.)
| | | | - Marion J.J. Gijbels
- From the Department of Medical Biochemistry (N.M.v.L., R.O., M.M., S.S., M.J.J.G., N.Z.)
- Department of Molecular Genetics (M.J.J.G.)
| | | | - Vincenzo Sorrentino
- CARIM, Maastricht University, The Netherlands; and Laboratory for Integrative and Systems Physiology, EPFL, Lausanne, Switzerland (V.S.)
| | - Jimmy F.P. Berbée
- Academic Medical Center, University of Amsterdam, The Netherlands; Division of Endocrinology, Department of Medicine, Einthoven Laboratory for Experimental Vascular and Regenerative Medicine, Leiden University Medical Center, The Netherlands (S.K., J.F.P.B., P.C.N.R.)
| | - Patrick C.N. Rensen
- Academic Medical Center, University of Amsterdam, The Netherlands; Division of Endocrinology, Department of Medicine, Einthoven Laboratory for Experimental Vascular and Regenerative Medicine, Leiden University Medical Center, The Netherlands (S.K., J.F.P.B., P.C.N.R.)
| | - Noam Zelcer
- From the Department of Medical Biochemistry (N.M.v.L., R.O., M.M., S.S., M.J.J.G., N.Z.)
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Clathrin-mediated endocytosis is a candidate entry sorting mechanism for Bombyx mori cypovirus. Sci Rep 2018; 8:7268. [PMID: 29740149 PMCID: PMC5940776 DOI: 10.1038/s41598-018-25677-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 04/24/2018] [Indexed: 12/19/2022] Open
Abstract
Bombyx mori cypovirus (BmCPV), a member of the Reoviridae, specifically infects silkworms and causes extensive economic losses to the sericulture industry. To date, the entry mechanism of BmCPV into cells is unclear. Here we used electron microscopy to study the route of entry of BmCPV into cells, and the results demonstrated that the entry of BmCPV into BmN cells was mediated by endocytosis. Blocking the entry pathway with four endocytosis inhibitors, including dansylcadaverine, chlorpromazine, genistein, and PP2, significantly decreased the infectivity of BmCPV. This indicates that BmCPV enters BmN cells via endocytosis, and that clathrin-mediated sorting is the predominant entry method. After the relative expression levels of clathrin heavy chain (clathrin, GenBank accession No. NM_001142971.1) and the adaptor protein complex-1 gamma subunit AP-1 (AP-1, GenBank accession No. JQ824201.1), which are involved in clathrin-mediated endocytosis, were inhibited by RNA interference or abolishing the functions of clathrin and AP-1 with their corresponding antibodies, the infectivity of BmCPV was reduced significantly, which suggests that clathrin-mediated endocytosis contributed to the entry of BmCPV into cells. Our findings suggest that the clathrin-mediated endocytosis pathway is a candidate for the development of therapeutics for silkworm cytoplasmic polyhedrosis.
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Gulluni F, Martini M, De Santis MC, Campa CC, Ghigo A, Margaria JP, Ciraolo E, Franco I, Ala U, Annaratone L, Disalvatore D, Bertalot G, Viale G, Noatynska A, Compagno M, Sigismund S, Montemurro F, Thelen M, Fan F, Meraldi P, Marchiò C, Pece S, Sapino A, Chiarle R, Di Fiore PP, Hirsch E. Mitotic Spindle Assembly and Genomic Stability in Breast Cancer Require PI3K-C2α Scaffolding Function. Cancer Cell 2017; 32:444-459.e7. [PMID: 29017056 DOI: 10.1016/j.ccell.2017.09.002] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 07/25/2017] [Accepted: 09/05/2017] [Indexed: 12/11/2022]
Abstract
Proper organization of the mitotic spindle is key to genetic stability, but molecular components of inter-microtubule bridges that crosslink kinetochore fibers (K-fibers) are still largely unknown. Here we identify a kinase-independent function of class II phosphoinositide 3-OH kinase α (PI3K-C2α) acting as limiting scaffold protein organizing clathrin and TACC3 complex crosslinking K-fibers. Downregulation of PI3K-C2α causes spindle alterations, delayed anaphase onset, and aneuploidy, indicating that PI3K-C2α expression is required for genomic stability. Reduced abundance of PI3K-C2α in breast cancer models initially impairs tumor growth but later leads to the convergent evolution of fast-growing clones with mitotic checkpoint defects. As a consequence of altered spindle, loss of PI3K-C2α increases sensitivity to taxane-based therapy in pre-clinical models and in neoadjuvant settings.
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Affiliation(s)
- Federico Gulluni
- Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Turin 10126, Italy
| | - Miriam Martini
- Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Turin 10126, Italy.
| | - Maria Chiara De Santis
- Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Turin 10126, Italy
| | - Carlo Cosimo Campa
- Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Turin 10126, Italy
| | - Alessandra Ghigo
- Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Turin 10126, Italy
| | - Jean Piero Margaria
- Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Turin 10126, Italy
| | - Elisa Ciraolo
- Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Turin 10126, Italy
| | - Irene Franco
- Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Turin 10126, Italy
| | - Ugo Ala
- Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Turin 10126, Italy
| | - Laura Annaratone
- Department of Medical Sciences, University of Torino, Turin, Italy; Pathology Unit, Department of Laboratory Medicine, Azienda Ospedaliera Universitaria Città della Salute e della Scienza di Torino, Turin, Italy
| | - Davide Disalvatore
- IFOM, The FIRC Institute for Molecular Oncology Foundation, Milan, Italy
| | - Giovanni Bertalot
- Program of Molecular Medicine, IEO, European Institute of Oncology, Milan, Italy
| | - Giuseppe Viale
- Division of Pathology, European Institute of Oncology, Milan, Italy; Department of Oncology and Hemato-oncology (DIPO), University of Milan, Milan, Italy
| | - Anna Noatynska
- Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - Mara Compagno
- Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Turin 10126, Italy; Department of Pathology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Sara Sigismund
- IFOM, The FIRC Institute for Molecular Oncology Foundation, Milan, Italy
| | - Filippo Montemurro
- Unit of Investigative Oncology, Candiolo Cancer Institute - FPO, IRCCS, Candiolo (TO), Italy
| | - Marcus Thelen
- Institute for Research in Biomedicine, Università della Svizzera Italiana, Bellinzona, Switzerland
| | - Fan Fan
- Department of Biological Science and Bioengineering, Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China
| | - Patrick Meraldi
- Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - Caterina Marchiò
- Department of Medical Sciences, University of Torino, Turin, Italy; Pathology Unit, Department of Laboratory Medicine, Azienda Ospedaliera Universitaria Città della Salute e della Scienza di Torino, Turin, Italy
| | - Salvatore Pece
- Program of Molecular Medicine, IEO, European Institute of Oncology, Milan, Italy; Department of Oncology and Hemato-oncology (DIPO), University of Milan, Milan, Italy
| | - Anna Sapino
- Department of Medical Sciences, University of Torino, Turin, Italy; Unit of Pathology, Candiolo Cancer Institute - FPO, IRCCS, Candiolo (TO), Italy
| | - Roberto Chiarle
- Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Turin 10126, Italy; Department of Pathology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Pier Paolo Di Fiore
- IFOM, The FIRC Institute for Molecular Oncology Foundation, Milan, Italy; Program of Molecular Medicine, IEO, European Institute of Oncology, Milan, Italy; Department of Oncology and Hemato-oncology (DIPO), University of Milan, Milan, Italy
| | - Emilio Hirsch
- Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Turin 10126, Italy.
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Chen SF, Chen PY, Hsu HJ, Wu MJ, Yen JH. Xanthohumol Suppresses Mylip/Idol Gene Expression and Modulates LDLR Abundance and Activity in HepG2 Cells. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2017; 65:7908-7918. [PMID: 28812343 DOI: 10.1021/acs.jafc.7b02282] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Xanthohumol, a prenylated flavonoid found in hops (Humulus lupulus L.), exhibits multiple biological activities such as antiatherosclerosis and hypolipidemic activities. In this study, we aim to investigate the hypocholesterolemic effects and molecular mechanisms of xanthohumol in hepatic cells. We found that xanthohumol (10 and 20 μM) increased the amount of cell-surface low-density lipoprotein receptor (LDLR) from 100.0 ± 2.1% to 115.0 ± 1.3% and 135.2 ± 2.7%, and enhanced the LDL uptake activity from 100.0 ± 0.9% to 139.1 ± 13.2% in HepG2 cells (p < 0.01). The mRNA levels of LDLR, HMGCR, and PCSK9 were not altered. Xanthohumol (20 μM) reduced the expression of inducible degrader of the LDL receptor (Mylip/Idol) mRNA and protein by approximately 45% (p < 0.01), which was reported to be associated with increases of LDLR level. We demonstrated that xanthohumol suppressed hepatic Mylip/Idol expression via counteracting liver X receptor (LXR) activation. The molecular docking results predicted that xanthohumol has a high binding affinity to interact with the LXRα ligand-binding domain, which may result in attenuation of LXRα-induced Mylip/Idol expression. Finally, we demonstrated that the Mylip/Idol expression and LDLR activity were synergistically changed by a combination of xanthohumol and simvastatin treatment. Our findings indicated that xanthohumol may regulate the LXR-Mylip/Idol axis to modulate hepatic LDLR abundance and activity.
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Affiliation(s)
- Shih-Fen Chen
- Department of Molecular Biology and Human Genetics, Tzu Chi University , Hualien 970, Taiwan
| | - Pei-Yi Chen
- Center of Medical Genetics, Buddhist Tzu Chi General Hospital , Hualien 970, Taiwan
| | - Hao-Jen Hsu
- Department of Life Science, Tzu Chi University , Hualien 970, Taiwan
| | - Ming-Jiuan Wu
- Department of Biotechnology, Chia-Nan University of Pharmacy and Science , Tainan 717, Taiwan
| | - Jui-Hung Yen
- Department of Molecular Biology and Human Genetics, Tzu Chi University , Hualien 970, Taiwan
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Hypercholesterolemia: The role of PCSK9. Arch Biochem Biophys 2017; 625-626:39-53. [DOI: 10.1016/j.abb.2017.06.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 05/29/2017] [Accepted: 06/02/2017] [Indexed: 01/06/2023]
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Bian F, Cui J, Zheng T, Jin S. Reactive oxygen species mediate angiotensin II-induced transcytosis of low-density lipoprotein across endothelial cells. Int J Mol Med 2017; 39:629-635. [PMID: 28204818 PMCID: PMC5360350 DOI: 10.3892/ijmm.2017.2887] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 01/03/2017] [Indexed: 11/06/2022] Open
Abstract
The retention of plasma low-density lipoprotein (LDL) particles to subendothelial spaces through transcytosis across the endothelium is the initial step of atherosclerosis (AS). Angiotensin II (Ang II), as the principal effector molecule of the renin-angiotensin system (RAS), is implicated in several important steps of AS development. However, whether or not Ang II can directly exert a pro‑atherogenic effect by promoting LDL transcytosis across endothelial barriers, has not been defined. In the present study, we found that Ang II upregulated intracellular reactive oxygen species (ROS) levels in endothelial cells (ECs) by measuring fluorescence of 2',7'-dichlorofluorescein (DCF‑DA). Based on our transcytosis model, we observed that Ang II significantly accelerated LDL transcytosis, whereas transcytosis inhibitor methyl-β-cyclodextrin (MβCD) and ROS inhibitor dithiothreitol (DTT), markedly blocked the Ang II-stimulated increase in LDL transcytosis. Confocal imaging analysis revealed that both LDL uptake by cells and LDL retention in human umbilical venous walls were highly elevated after Ang II exposure, while MβCD and DTT significantly inhibited the effects of Ang II. What is more, proteins involved in caveolae-mediated transcytosis, including LDL receptor (LDLR), caveolin-1 and cavin-1, were associated with Ang II-induced LDL transcytosis across the ECs. Nevertheless, this process was independent of clathrin in our study. Of note, ROS inhibitor, DTT, markedly decreased the expression levels of those proteins. Consequently, ROS are critical mediators in Ang II-induced LDL transcytosis. Hopefully, these findings will provide novel insight into the crosstalk between dyslipidemia and RAS in atherogenesis.
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Affiliation(s)
- Fang Bian
- Department of Pharmacy, The Affiliated Hospital of Xiangyang Central Hospital of Hubei University of Arts and Science, Xiangyang, Hubei 441000, P.R. China
| | - Jun Cui
- Department of Cardiothoracic Surgery, The Affiliated Hospital of Xiangyang Central Hospital of Hubei University of Arts and Science, Xiangyang, Hubei 441000, P.R. China
| | - Tao Zheng
- Department of Endocrinology, Institute of Geriatric Medicine, Liyuan Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Si Jin
- Department of Endocrinology, Institute of Geriatric Medicine, Liyuan Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
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Courtney R, Landreth GE. LXR Regulation of Brain Cholesterol: From Development to Disease. Trends Endocrinol Metab 2016; 27:404-414. [PMID: 27113081 PMCID: PMC4986614 DOI: 10.1016/j.tem.2016.03.018] [Citation(s) in RCA: 120] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 03/31/2016] [Accepted: 03/31/2016] [Indexed: 01/07/2023]
Abstract
Liver X receptors (LXRs) are master regulators of cholesterol homeostasis and inflammation in the central nervous system (CNS). The brain, which contains a disproportionately large amount of the body's total cholesterol (∼25%), requires a complex and delicately balanced cholesterol metabolism to maintain neuronal function. Dysregulation of cholesterol metabolism has been implicated in numerous neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD). Due to their cholesterol-sensing and anti-inflammatory activities, LXRs are positioned centrally in the everyday maintenance of CNS function. This review focuses on recent research into the role of LXRs in the CNS during normal development and homeostasis and in disease states.
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Affiliation(s)
- Rebecca Courtney
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Gary E Landreth
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH 44106, USA.
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40
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Grassi G, Di Caprio G, Fimia GM, Ippolito G, Tripodi M, Alonzi T. Hepatitis C virus relies on lipoproteins for its life cycle. World J Gastroenterol 2016; 22:1953-1965. [PMID: 26877603 PMCID: PMC4726671 DOI: 10.3748/wjg.v22.i6.1953] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 10/19/2015] [Accepted: 12/21/2015] [Indexed: 02/06/2023] Open
Abstract
Hepatitis C virus (HCV) infects over 150 million people worldwide. In most cases, HCV infection becomes chronic causing liver disease ranging from fibrosis to cirrhosis and hepatocellular carcinoma. Viral persistence and pathogenesis are due to the ability of HCV to deregulate specific host processes, mainly lipid metabolism and innate immunity. In particular, HCV exploits the lipoprotein machineries for almost all steps of its life cycle. The aim of this review is to summarize current knowledge concerning the interplay between HCV and lipoprotein metabolism. We discuss the role played by members of lipoproteins in HCV entry, replication and virion production.
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Nelson JK, Cook ECL, Loregger A, Hoeksema MA, Scheij S, Kovacevic I, Hordijk PL, Ovaa H, Zelcer N. Deubiquitylase Inhibition Reveals Liver X Receptor-independent Transcriptional Regulation of the E3 Ubiquitin Ligase IDOL and Lipoprotein Uptake. J Biol Chem 2015; 291:4813-25. [PMID: 26719329 DOI: 10.1074/jbc.m115.698688] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Indexed: 01/05/2023] Open
Abstract
Cholesterol metabolism is subject to complex transcriptional and nontranscriptional regulation. Herein, the role of ubiquitylation is emerging as an important post-translational modification that regulates cholesterol synthesis and uptake. Similar to other post-translational modifications, ubiquitylation is reversible in a process dependent on activity of deubiquitylating enzymes (DUBs). Yet whether these play a role in cholesterol metabolism is largely unknown. As a first step to test this possibility, we used pharmacological inhibition of cellular DUB activity. Short term (2 h) inhibition of DUBs resulted in accumulation of high molecular weight ubiquitylated proteins. This was accompanied by a dramatic decrease in abundance of the LDLR and attenuated LDL uptake into hepatic cells. Importantly, this occurred in the absence of changes in the mRNA levels of the LDLR or other SREBP2-regulated genes, in line with this phenotype being a post-transcriptional event. Mechanistically, we identify transcriptional induction of the E3 ubiquitin ligase IDOL in human and rodent cells as the underlying cause for ubiquitylation-dependent lysosomal degradation of the LDLR following DUB inhibition. In contrast to the established transcriptional regulation of IDOL by the sterol-responsive liver X receptor (LXR) transcription factors, induction of IDOL by DUB inhibition is LXR-independent and occurs in Lxrαβ(-/-) MEFs. Consistent with the role of DUBs in transcriptional regulation, we identified a 70-bp region in the proximal promoter of IDOL, distinct from that containing the LXR-responsive element, which mediates the response to DUB inhibition. In conclusion, we identify a sterol-independent mechanism to regulate IDOL expression and IDOL-mediated lipoprotein receptor degradation.
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Affiliation(s)
- Jessica Kristine Nelson
- From the Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
| | - Emma Clare Laura Cook
- From the Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
| | - Anke Loregger
- From the Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
| | - Marten Anne Hoeksema
- From the Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
| | - Saskia Scheij
- From the Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
| | - Igor Kovacevic
- the Department of Molecular Cell Biology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, 1066 CX Amsterdam, The Netherlands, and
| | - Peter Lodewijk Hordijk
- the Department of Molecular Cell Biology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, 1066 CX Amsterdam, The Netherlands, and
| | - Huib Ovaa
- the Department of Cell Biology, The Netherlands Cancer Institute, 1066 CX Amsterdam, The Netherlands
| | - Noam Zelcer
- From the Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands,
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Nelson JK, Sorrentino V, Avagliano Trezza R, Heride C, Urbe S, Distel B, Zelcer N. The Deubiquitylase USP2 Regulates the LDLR Pathway by Counteracting the E3-Ubiquitin Ligase IDOL. Circ Res 2015; 118:410-9. [PMID: 26666640 DOI: 10.1161/circresaha.115.307298] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 12/14/2015] [Indexed: 12/26/2022]
Abstract
RATIONALE The low-density lipoprotein (LDL) receptor (LDLR) is a central determinant of circulating LDL-cholesterol and as such subject to tight regulation. Recent studies and genetic evidence implicate the inducible degrader of the LDLR (IDOL) as a regulator of LDLR abundance and of circulating levels of LDL-cholesterol in humans. Acting as an E3-ubiquitin ligase, IDOL promotes ubiquitylation and subsequent lysosomal degradation of the LDLR. Consequently, inhibition of IDOL-mediated degradation of the LDLR represents a potential strategy to increase hepatic LDL-cholesterol clearance. OBJECTIVE To establish whether deubiquitylases counteract IDOL-mediated ubiquitylation and degradation of the LDLR. METHODS AND RESULTS Using a genetic screening approach, we identify the ubiquitin-specific protease 2 (USP2) as a post-transcriptional regulator of IDOL-mediated LDLR degradation. We demonstrate that both USP2 isoforms, USP2-69 and USP2-45, interact with IDOL and promote its deubiquitylation. IDOL deubiquitylation requires USP2 enzymatic activity and leads to a marked stabilization of IDOL protein. Paradoxically, this also markedly attenuates IDOL-mediated degradation of the LDLR and the ability of IDOL to limit LDL uptake into cells. Conversely, loss of USP2 reduces LDLR protein in an IDOL-dependent manner and limits LDL uptake. We identify a tri-partite complex encompassing IDOL, USP2, and LDLR and demonstrate that in this context USP2 promotes deubiquitylation of the LDLR and prevents its degradation. CONCLUSIONS Our findings identify USP2 as a novel regulator of lipoprotein clearance owing to its ability to control ubiquitylation-dependent degradation of the LDLR by IDOL.
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Affiliation(s)
- Jessica Kristine Nelson
- From the Department of Medical Biochemistry, Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands (J.K.N., V.S., R.A.T., B.D., N.Z.); and Department of Cellular and Molecular Physiology, University of Liverpool, Liverpool, United Kingdom (C.H., S.U.)
| | - Vincenzo Sorrentino
- From the Department of Medical Biochemistry, Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands (J.K.N., V.S., R.A.T., B.D., N.Z.); and Department of Cellular and Molecular Physiology, University of Liverpool, Liverpool, United Kingdom (C.H., S.U.)
| | - Rossella Avagliano Trezza
- From the Department of Medical Biochemistry, Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands (J.K.N., V.S., R.A.T., B.D., N.Z.); and Department of Cellular and Molecular Physiology, University of Liverpool, Liverpool, United Kingdom (C.H., S.U.)
| | - Claire Heride
- From the Department of Medical Biochemistry, Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands (J.K.N., V.S., R.A.T., B.D., N.Z.); and Department of Cellular and Molecular Physiology, University of Liverpool, Liverpool, United Kingdom (C.H., S.U.)
| | - Sylvie Urbe
- From the Department of Medical Biochemistry, Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands (J.K.N., V.S., R.A.T., B.D., N.Z.); and Department of Cellular and Molecular Physiology, University of Liverpool, Liverpool, United Kingdom (C.H., S.U.)
| | - Ben Distel
- From the Department of Medical Biochemistry, Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands (J.K.N., V.S., R.A.T., B.D., N.Z.); and Department of Cellular and Molecular Physiology, University of Liverpool, Liverpool, United Kingdom (C.H., S.U.)
| | - Noam Zelcer
- From the Department of Medical Biochemistry, Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands (J.K.N., V.S., R.A.T., B.D., N.Z.); and Department of Cellular and Molecular Physiology, University of Liverpool, Liverpool, United Kingdom (C.H., S.U.).
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Lu X, Meima ME, Nelson JK, Sorrentino V, Loregger A, Scheij S, Dekkers DHW, Mulder MT, Demmers JAA, M-Dallinga-Thie G, Zelcer N, Danser AHJ. Identification of the (Pro)renin Receptor as a Novel Regulator of Low-Density Lipoprotein Metabolism. Circ Res 2015; 118:222-9. [PMID: 26582775 DOI: 10.1161/circresaha.115.306799] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 11/18/2015] [Indexed: 01/16/2023]
Abstract
RATIONALE The (pro)renin receptor ([P]RR) interacts with (pro)renin at concentrations that are >1000× higher than observed under (patho)physiological conditions. Recent studies have identified renin-angiotensin system-independent functions for (P)RR related to its association with the vacuolar H(+)-ATPase. OBJECTIVE To uncover renin-angiotensin system-independent functions of the (P)RR. METHODS AND RESULTS We used a proteomics-based approach to purify and identify (P)RR-interacting proteins. This resulted in identification of sortilin-1 (SORT1) as a high-confidence (P)RR-interacting protein, a finding which was confirmed by coimmunoprecipitation of endogenous (P)RR and SORT1. Functionally, silencing (P)RR expression in hepatocytes decreased SORT1 and low-density lipoprotein (LDL) receptor protein abundance and, as a consequence, resulted in severely attenuated cellular LDL uptake. In contrast to LDL, endocytosis of epidermal growth factor or transferrin remained unaffected by silencing of the (P)RR. Importantly, reduction of LDL receptor and SORT1 protein abundance occurred in the absence of changes in their corresponding transcript level. Consistent with a post-transcriptional event, degradation of the LDL receptor induced by (P)RR silencing could be reversed by lysosomotropic agents, such as bafilomycin A1. CONCLUSIONS Our study identifies a renin-angiotensin system-independent function for the (P)RR in the regulation of LDL metabolism by controlling the levels of SORT1 and LDL receptor.
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Affiliation(s)
- Xifeng Lu
- From the Astra Zeneca-Shenzhen University Joint Institute of Nephrology, Shenzhen University Medical Center, Shenzhen University, Shenzhen, China (X.L.); Division of Pharmacology and Vascular Medicine, Department of Internal Medicine (X.L., M.E.M., M.T.M., A.H.J.D.) and Proteomics Center (D.H.W.D., J.A.A.D.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Medical Biochemistry (X.L., J.K.N., V.S., A.L., S.S., N.Z.) and Laboratory of Experimental Vascular Medicine (G.M.D-.T.), Academic Medical Center, Amsterdam, The Netherlands
| | - Marcel E Meima
- From the Astra Zeneca-Shenzhen University Joint Institute of Nephrology, Shenzhen University Medical Center, Shenzhen University, Shenzhen, China (X.L.); Division of Pharmacology and Vascular Medicine, Department of Internal Medicine (X.L., M.E.M., M.T.M., A.H.J.D.) and Proteomics Center (D.H.W.D., J.A.A.D.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Medical Biochemistry (X.L., J.K.N., V.S., A.L., S.S., N.Z.) and Laboratory of Experimental Vascular Medicine (G.M.D-.T.), Academic Medical Center, Amsterdam, The Netherlands
| | - Jessica K Nelson
- From the Astra Zeneca-Shenzhen University Joint Institute of Nephrology, Shenzhen University Medical Center, Shenzhen University, Shenzhen, China (X.L.); Division of Pharmacology and Vascular Medicine, Department of Internal Medicine (X.L., M.E.M., M.T.M., A.H.J.D.) and Proteomics Center (D.H.W.D., J.A.A.D.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Medical Biochemistry (X.L., J.K.N., V.S., A.L., S.S., N.Z.) and Laboratory of Experimental Vascular Medicine (G.M.D-.T.), Academic Medical Center, Amsterdam, The Netherlands
| | - Vincenzo Sorrentino
- From the Astra Zeneca-Shenzhen University Joint Institute of Nephrology, Shenzhen University Medical Center, Shenzhen University, Shenzhen, China (X.L.); Division of Pharmacology and Vascular Medicine, Department of Internal Medicine (X.L., M.E.M., M.T.M., A.H.J.D.) and Proteomics Center (D.H.W.D., J.A.A.D.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Medical Biochemistry (X.L., J.K.N., V.S., A.L., S.S., N.Z.) and Laboratory of Experimental Vascular Medicine (G.M.D-.T.), Academic Medical Center, Amsterdam, The Netherlands
| | - Anke Loregger
- From the Astra Zeneca-Shenzhen University Joint Institute of Nephrology, Shenzhen University Medical Center, Shenzhen University, Shenzhen, China (X.L.); Division of Pharmacology and Vascular Medicine, Department of Internal Medicine (X.L., M.E.M., M.T.M., A.H.J.D.) and Proteomics Center (D.H.W.D., J.A.A.D.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Medical Biochemistry (X.L., J.K.N., V.S., A.L., S.S., N.Z.) and Laboratory of Experimental Vascular Medicine (G.M.D-.T.), Academic Medical Center, Amsterdam, The Netherlands
| | - Saskia Scheij
- From the Astra Zeneca-Shenzhen University Joint Institute of Nephrology, Shenzhen University Medical Center, Shenzhen University, Shenzhen, China (X.L.); Division of Pharmacology and Vascular Medicine, Department of Internal Medicine (X.L., M.E.M., M.T.M., A.H.J.D.) and Proteomics Center (D.H.W.D., J.A.A.D.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Medical Biochemistry (X.L., J.K.N., V.S., A.L., S.S., N.Z.) and Laboratory of Experimental Vascular Medicine (G.M.D-.T.), Academic Medical Center, Amsterdam, The Netherlands
| | - Dick H W Dekkers
- From the Astra Zeneca-Shenzhen University Joint Institute of Nephrology, Shenzhen University Medical Center, Shenzhen University, Shenzhen, China (X.L.); Division of Pharmacology and Vascular Medicine, Department of Internal Medicine (X.L., M.E.M., M.T.M., A.H.J.D.) and Proteomics Center (D.H.W.D., J.A.A.D.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Medical Biochemistry (X.L., J.K.N., V.S., A.L., S.S., N.Z.) and Laboratory of Experimental Vascular Medicine (G.M.D-.T.), Academic Medical Center, Amsterdam, The Netherlands
| | - Monique T Mulder
- From the Astra Zeneca-Shenzhen University Joint Institute of Nephrology, Shenzhen University Medical Center, Shenzhen University, Shenzhen, China (X.L.); Division of Pharmacology and Vascular Medicine, Department of Internal Medicine (X.L., M.E.M., M.T.M., A.H.J.D.) and Proteomics Center (D.H.W.D., J.A.A.D.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Medical Biochemistry (X.L., J.K.N., V.S., A.L., S.S., N.Z.) and Laboratory of Experimental Vascular Medicine (G.M.D-.T.), Academic Medical Center, Amsterdam, The Netherlands
| | - Jeroen A A Demmers
- From the Astra Zeneca-Shenzhen University Joint Institute of Nephrology, Shenzhen University Medical Center, Shenzhen University, Shenzhen, China (X.L.); Division of Pharmacology and Vascular Medicine, Department of Internal Medicine (X.L., M.E.M., M.T.M., A.H.J.D.) and Proteomics Center (D.H.W.D., J.A.A.D.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Medical Biochemistry (X.L., J.K.N., V.S., A.L., S.S., N.Z.) and Laboratory of Experimental Vascular Medicine (G.M.D-.T.), Academic Medical Center, Amsterdam, The Netherlands
| | - Geesje M-Dallinga-Thie
- From the Astra Zeneca-Shenzhen University Joint Institute of Nephrology, Shenzhen University Medical Center, Shenzhen University, Shenzhen, China (X.L.); Division of Pharmacology and Vascular Medicine, Department of Internal Medicine (X.L., M.E.M., M.T.M., A.H.J.D.) and Proteomics Center (D.H.W.D., J.A.A.D.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Medical Biochemistry (X.L., J.K.N., V.S., A.L., S.S., N.Z.) and Laboratory of Experimental Vascular Medicine (G.M.D-.T.), Academic Medical Center, Amsterdam, The Netherlands
| | - Noam Zelcer
- From the Astra Zeneca-Shenzhen University Joint Institute of Nephrology, Shenzhen University Medical Center, Shenzhen University, Shenzhen, China (X.L.); Division of Pharmacology and Vascular Medicine, Department of Internal Medicine (X.L., M.E.M., M.T.M., A.H.J.D.) and Proteomics Center (D.H.W.D., J.A.A.D.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Medical Biochemistry (X.L., J.K.N., V.S., A.L., S.S., N.Z.) and Laboratory of Experimental Vascular Medicine (G.M.D-.T.), Academic Medical Center, Amsterdam, The Netherlands.
| | - A H Jan Danser
- From the Astra Zeneca-Shenzhen University Joint Institute of Nephrology, Shenzhen University Medical Center, Shenzhen University, Shenzhen, China (X.L.); Division of Pharmacology and Vascular Medicine, Department of Internal Medicine (X.L., M.E.M., M.T.M., A.H.J.D.) and Proteomics Center (D.H.W.D., J.A.A.D.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Medical Biochemistry (X.L., J.K.N., V.S., A.L., S.S., N.Z.) and Laboratory of Experimental Vascular Medicine (G.M.D-.T.), Academic Medical Center, Amsterdam, The Netherlands.
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IDOL, inducible degrader of low-density lipoprotein receptor, serves as a potential therapeutic target for dyslipidemia. Med Hypotheses 2015; 86:138-42. [PMID: 26601593 DOI: 10.1016/j.mehy.2015.11.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 07/19/2015] [Accepted: 11/08/2015] [Indexed: 11/24/2022]
Abstract
Low-density lipoprotein cholesterol (LDL-C) is the hall marker for the atherosclerotic cardiovascular disease (ASCVD). It has been shown that over 70% of circulating LDL-C is metabolized through binding and activation of hepatic LDL receptor (LDLR). Genetic LDLR mutations cause hypercholesterolemia in the patients. Therefore, elevation of LDLR levels is beneficial for the treatment of dyslipidemia. LDLR expression is regulated by the SREBP2/PCSK9 pathways. Targeting SREBP2/PCSK9 pathways by statins and human monoclonal PCSK9 antibody has been shown to reduce the progression of ASVCD. Recent studies identified that inducible degrader of LDLR (IDOL) is a novel regulator of LDLR. IDOL is an E3-ubiquitin ligase regulated via liver X receptors (LXRs) binding to the upstream of translation start site of IDOL. IDOL modulates LDLR distribution through ubiquitination and degradation of LDLR in lysosomes. Genome-wide association studies (GWAS) have revealed that the nonsynonymous substitution rs9370867 of IDOL probably contributes to the variability of circulating LDL levels. Recently studies also demonstrated that IDOL influences PCSK9 expression in a LDLR/SREBP2-dependent manner. Based upon these novel findings, we hypothesize that IDOL and PCSK9 would have a synergistic effect on LDLR distribution. Specifically, loss of IDOL increases LDLR distribution in the hepatic cell, and subsequently reduces serum LDL-C levels in dyslipidemic patients. IDOL might be a potential therapeutic target for the treatment of ASCVD.
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A MARCH6 and IDOL E3 Ubiquitin Ligase Circuit Uncouples Cholesterol Synthesis from Lipoprotein Uptake in Hepatocytes. Mol Cell Biol 2015; 36:285-94. [PMID: 26527619 DOI: 10.1128/mcb.00890-15] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 10/27/2015] [Indexed: 11/20/2022] Open
Abstract
Cholesterol synthesis and lipoprotein uptake are tightly coordinated to ensure that the cellular level of cholesterol is adequately maintained. Hepatic dysregulation of these processes is associated with pathological conditions, most notably cardiovascular disease. Using a genetic approach, we have recently identified the E3 ubiquitin ligase MARCH6 as a regulator of cholesterol biosynthesis, owing to its ability to promote degradation of the rate-limiting enzymes 3-hydroxy-3-methyl-glutaryl coenzyme A reductase (HMGCR) and squalene epoxidase (SQLE). Here, we present evidence for MARCH6 playing a multifaceted role in the control of cholesterol homeostasis in hepatocytes. We identify MARCH6 as an endogenous inhibitor of the sterol regulatory element binding protein (SREBP) transcriptional program. Accordingly, loss of MARCH6 increases expression of SREBP-regulated genes involved in cholesterol biosynthesis and lipoprotein uptake. Unexpectedly, this is associated with a decrease in cellular lipoprotein uptake, induced by enhanced lysosomal degradation of the low-density lipoprotein receptor (LDLR). Finally, we provide evidence that induction of the E3 ubiquitin ligase IDOL represents the molecular mechanism underlying this MARCH6-induced phenotype. Our study thus highlights a MARCH6-dependent mechanism to direct cellular cholesterol accretion that relies on uncoupling of cholesterol synthesis from lipoprotein uptake.
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46
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Di Taranto MD, D'Agostino MN, Fortunato G. Functional characterization of mutant genes associated with autosomal dominant familial hypercholesterolemia: integration and evolution of genetic diagnosis. Nutr Metab Cardiovasc Dis 2015; 25:979-987. [PMID: 26165249 DOI: 10.1016/j.numecd.2015.06.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 06/15/2015] [Indexed: 12/18/2022]
Abstract
AIMS Familial Hypercholesterolemia (FH) is one of the most frequent dyslipidemias, the autosomal dominant form of which is primarily caused by mutations in the LDL receptor (LDLR), apolipoprotein B (APOB), and proprotein convertase subtilisin/kexin type 9 (PCSK9) genes, although in around 20% of patients the genetic cause remains unidentified. Genetic testing has notably improved the identification of patients suffering from FH, the most frequent cause of which is the presence of mutations in the LDLR gene. Although more than 1200 different mutations have been identified in this gene, about 80% are recognized to be pathogenic. We aim to overview the current methods used to perform the functional characterization of mutations causing FH and to highlight the conditions requiring a functional characterization of the variant in order to obtain a diagnostic report. DATA SYNTHESIS In the current review, we summarize the different types of functional assays - including their advantages and disadvantages - performed to characterize mutations in the LDLR, APOB and PCSK9 genes helping to better define their pathogenic role. We describe the evaluation of splicing alterations and two major procedures for functional characterization: 1. ex vivo methods, using cells from FH patients; 2. in vitro methods using cell lines. CONCLUSIONS Functional characterization of the LDLR, APOB and PCSK9 mutant genes associated with FH can be considered a necessary integration of its genetic diagnosis.
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Affiliation(s)
| | - M N D'Agostino
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Via Sergio Pansini 5, 80131 Napoli, Italy
| | - G Fortunato
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Via Sergio Pansini 5, 80131 Napoli, Italy; CEINGE Biotecnologie Avanzate S.C.a r.l., Via Gaetano Salvatore 486, 80145 Napoli, Italy.
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47
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Kuder CH, Weivoda MM, Zhang Y, Zhu J, Neighbors JD, Wiemer DF, Hohl RJ. 3-Deoxyschweinfurthin B Lowers Cholesterol Levels by Decreasing Synthesis and Increasing Export in Cultured Cancer Cell Lines. Lipids 2015; 50:1195-207. [PMID: 26494560 DOI: 10.1007/s11745-015-4083-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 10/02/2015] [Indexed: 01/12/2023]
Abstract
The schweinfurthins have potent antiproliferative activity in multiple glioblastoma multiforme (GBM) cell lines; however, the mechanism by which growth is impeded is not fully understood. Previously, we demonstrated that the schweinfurthins reduce the level of key isoprenoid intermediates in the cholesterol biosynthetic pathway. Herein, we describe the effects of the schweinfurthins on cholesterol homeostasis. Intracellular cholesterol levels are greatly reduced in cells incubated with 3-deoxyschweinfurthin B (3dSB), an analog of the natural product schweinfurthin B. Decreased cholesterol levels are due to decreased cholesterol synthesis and increased cholesterol efflux; both of these cellular actions can be influenced by liver X-receptor (LXR) activation. The effects of 3dSB on ATP-binding cassette transporter 1 levels and other LXR targets are similar to that of 25-hydroxycholesterol, an LXR agonist. Unlike 25-hydroxycholesterol, 3dSB does not act as a direct agonist for LXR α or β. These data suggest that cholesterol homeostasis plays a significant role in the growth inhibitory activity of the schweinfurthins and may elucidate a mechanism that can be targeted in human cancers such as GBM.
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Affiliation(s)
- Craig H Kuder
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Megan M Weivoda
- Department of Pharmacology, University of Iowa, Iowa City, IA, 52242, USA.,Department of Endocrinology, Mayo Clinic, Rochester, MN, USA
| | - Ying Zhang
- Department of Public Health Sciences, Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - Junjia Zhu
- Department of Public Health Sciences, Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - Jeffrey D Neighbors
- Department of Chemistry, University of Iowa, Iowa City, IA, 52242, USA.,Department of Pharmacology, Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - David F Wiemer
- Department of Pharmacology, University of Iowa, Iowa City, IA, 52242, USA.,Department of Chemistry, University of Iowa, Iowa City, IA, 52242, USA
| | - Raymond J Hohl
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA. .,Department of Pharmacology, University of Iowa, Iowa City, IA, 52242, USA. .,, Mail Code CH72, 500 University Drive, Hershey, PA, 17033-0850, USA. .,Departments of Medicine and Pharmacology, Pennsylvania State University College of Medicine, Hershey, PA, USA.
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Starr AE, Lemieux V, Noad J, Moore JI, Dewpura T, Raymond A, Chrétien M, Figeys D, Mayne J. β-Estradiol results in a proprotein convertase subtilisin/kexin type 9-dependent increase in low-density lipoprotein receptor levels in human hepatic HuH7 cells. FEBS J 2015; 282:2682-96. [PMID: 25913303 PMCID: PMC5008176 DOI: 10.1111/febs.13309] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 03/28/2015] [Accepted: 04/22/2015] [Indexed: 12/23/2022]
Abstract
The lower risk of coronary artery disease in premenopausal women than in men and postmenopausal women implicates sex steroids in cardioprotective processes. β-Estradiol upregulates liver low-density lipoprotein receptor (LDLR), which, in turn, decreases circulating levels of low-density lipoprotein, which is a risk factor for coronary artery disease. Conversely, LDLR protein is negatively regulated by proprotein convertase subtilisin/kexin type 9 (PCSK9). Herein, we investigated PCSK9 regulation by β-estradiol and its impact on LDLR in human hepatocarcinoma HuH7 cells grown in the presence or absence of β-estradiol. Immunoblot analysis showed upregulation of LDLR at 3 μm β-estradiol (140%), and the upregulation reached 220% at 10 μm β-estradiol; only at the latter dose was an increase in LDLR mRNA detected by qPCR, suggesting post-translational regulation of LDLR. No changes in PCSK9 mRNA or secreted protein levels were detected by qPCR or ELISA, respectively. β-estradiol-conditioned medium devoid of PCSK9 failed to upregulate LDLR. Similarly, PCSK9 knockdown cells showed no upregulation of LDLR by β-estradiol. Together, these results indicate a requirement for PCSK9 in the β-estradiol-induced upregulation of LDLR. A radiolabeling assay showed a significant, dose-dependent decrease in the ratio of secreted phosphoPCSK9 to total secreted PCSK9 with increasing β-estradiol levels, suggesting a change in the functional state of PCSK9 in the presence of β-estradiol. Our results indicate that the protein upregulation of LDLR at subtranscriptionally effective doses of β-estradiol, and its supratranscriptional upregulation at 10 μm β-estradiol, occur through an extracellular PCSK9-dependent mechanism.
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Affiliation(s)
- Amanda E Starr
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ontario, Canada
| | - Valérie Lemieux
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ontario, Canada
| | - Jenny Noad
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ontario, Canada
| | - Jasmine I Moore
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ontario, Canada
| | - Thilina Dewpura
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ontario, Canada
| | - Angela Raymond
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ontario, Canada
| | - Michel Chrétien
- Chronic Disease Program, Ottawa Hospital Research Institute, The Ottawa Hospital, Ontario, Canada.,Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, Quebec, Canada
| | - Daniel Figeys
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ontario, Canada
| | - Janice Mayne
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ontario, Canada
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49
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Hong C, Marshall SM, McDaniel AL, Graham M, Layne JD, Cai L, Scotti E, Boyadjian R, Kim J, Chamberlain BT, Tangirala RK, Jung ME, Fong L, Lee R, Young SG, Temel RE, Tontonoz P. The LXR-Idol axis differentially regulates plasma LDL levels in primates and mice. Cell Metab 2014; 20:910-918. [PMID: 25440061 PMCID: PMC4261644 DOI: 10.1016/j.cmet.2014.10.001] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 07/22/2014] [Accepted: 10/06/2014] [Indexed: 11/25/2022]
Abstract
The LXR-regulated E3 ubiquitin ligase IDOL controls LDLR receptor stability independent of SREBP and PCSK9, but its relevance to plasma lipid levels is unknown. Here we demonstrate that the effects of the LXR-IDOL axis are both tissue and species specific. In mice, LXR agonist induces Idol transcript levels in peripheral tissues but not in liver, and does not change plasma LDL levels. Accordingly, Idol-deficient mice exhibit elevated LDLR protein levels in peripheral tissues, but not in the liver. By contrast, LXR activation in cynomolgus monkeys induces hepatic IDOL expression, reduces LDLR protein levels, and raises plasma LDL levels. Knockdown of IDOL in monkeys with an antisense oligonucleotide blunts the effect of LXR agonist on LDL levels. These results implicate IDOL as a modulator of plasma lipid levels in primates and support further investigation into IDOL inhibition as a potential strategy for LDL lowering in humans.
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Affiliation(s)
- Cynthia Hong
- Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Stephanie M Marshall
- Department of Pathology, Section on Lipid Sciences, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
| | - Allison L McDaniel
- Department of Pathology, Section on Lipid Sciences, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
| | - Mark Graham
- Cardiovascular Antisense Drug Discovery Group, Isis Pharmaceuticals, Carlsbad, CA 92010, USA
| | - Joseph D Layne
- Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY 40536, USA
| | - Lei Cai
- Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY 40536, USA
| | - Elena Scotti
- Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Rima Boyadjian
- Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Jason Kim
- Division of Endocrinology, Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Brian T Chamberlain
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Rajendra K Tangirala
- Division of Endocrinology, Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Michael E Jung
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Loren Fong
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Richard Lee
- Cardiovascular Antisense Drug Discovery Group, Isis Pharmaceuticals, Carlsbad, CA 92010, USA
| | - Stephen G Young
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Human Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Ryan E Temel
- Department of Pathology, Section on Lipid Sciences, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA; Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY 40536, USA.
| | - Peter Tontonoz
- Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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50
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Sharpe LJ, Cook ECL, Zelcer N, Brown AJ. The UPS and downs of cholesterol homeostasis. Trends Biochem Sci 2014; 39:527-35. [PMID: 25220377 DOI: 10.1016/j.tibs.2014.08.008] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 08/18/2014] [Accepted: 08/21/2014] [Indexed: 11/26/2022]
Abstract
An emerging theme in the regulation of cholesterol homeostasis is the role of the ubiquitin proteasome system (UPS), through which proteins are ubiquitylated and then degraded in response to specific signals. The UPS controls all aspects of cholesterol metabolism including its synthesis, uptake, and efflux. We review here recent work uncovering the ubiquitylation and degradation of key players in cholesterol homeostasis. This includes the low-density lipoprotein (LDL) receptor, transcription factors (sterol regulatory element binding proteins and liver X receptors), flux-controlling enzymes in cholesterol synthesis (3-hydroxy-3-methylglutaryl-CoA reductase and squalene monooxygenase), and cholesterol exporters (ATP-binding cassette transporters ABCA1 and ABCG1). We explore which E3 ligases are involved, and identify areas deserving of further research.
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Affiliation(s)
- Laura J Sharpe
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Emma C L Cook
- Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105AZ Amsterdam, The Netherlands
| | - Noam Zelcer
- Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105AZ Amsterdam, The Netherlands.
| | - Andrew J Brown
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2052, Australia.
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