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Chen L, Hong C, Chen EC, Yee SW, Xu L, Almof EU, Wen C, Fujii K, Johns SJ, Stryke D, Ferrin TE, Simko J, Chen X, Costello JF, Giacomini KM. Genetic and epigenetic regulation of the organic cation transporter 3, SLC22A3. THE PHARMACOGENOMICS JOURNAL 2012; 13:110-20. [PMID: 22231567 PMCID: PMC3396779 DOI: 10.1038/tpj.2011.60] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Human organic cation transporter 3 (OCT3 and SLC22A3) mediates the uptake of many important endogenous amines and basic drugs in a variety of tissues. OCT3 is identified as one of the important risk loci for prostate cancer, and is markedly underexpressed in aggressive prostate cancers. The goal of this study was to identify genetic and epigenetic factors in the promoter region that influence the expression level of OCT3. Haplotypes that contained the common variants, g.-81G>delGA (rs60515630) (minor allele frequency 11.5% in African American) and g.-2G>A (rs555754) (minor allele frequency>30% in all ethnic groups) showed significant increases in luciferase reporter activities and exhibited stronger transcription factor-binding affinity than the haplotypes that contained the major alleles. Consistent with the reporter assays, OCT3 messenger RNA expression levels were significantly higher in Asian (P<0.001) and Caucasian (P<0.05) liver samples from individuals who were homozygous for g.-2A/A in comparison with those homozygous for the g.-2G/G allele. Studies revealed that the methylation level in the basal promoter region of OCT3 was associated with OCT3 expression level and tumorigenesis capability in various prostate cancer cell lines. The methylation level of the OCT3 promoter was higher in 62% of prostate tumor samples compared with matched normal samples. Our studies demonstrate that genetic polymorphisms in the proximal promoter region of OCT3 alter the transcription rate of the gene and may be associated with altered expression levels of OCT3 in human liver. Aberrant methylation contributes to the reduced expression of OCT3 in prostate cancer.
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Hong C, Kidani Y, A-Gonzalez N, Phung T, Ito A, Rong X, Ericson K, Mikkola H, Beaven SW, Miller LS, Shao WH, Cohen PL, Castrillo A, Tontonoz P, Bensinger SJ. Coordinate regulation of neutrophil homeostasis by liver X receptors in mice. J Clin Invest 2011; 122:337-47. [PMID: 22156197 DOI: 10.1172/jci58393] [Citation(s) in RCA: 110] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Accepted: 10/24/2011] [Indexed: 12/21/2022] Open
Abstract
The most abundant immune cell type is the neutrophil, a key first responder after pathogen invasion. Neutrophil numbers in the periphery are tightly regulated to prevent opportunistic infections and aberrant inflammation. In healthy individuals, more than 1 × 10⁹ neutrophils per kilogram body weight are released from the bone marrow every 24 hours. To maintain homeostatic levels, an equivalent number of senescent cells must be cleared from circulation. Recent studies indicate that clearance of senescent neutrophils by resident tissue macrophages and DCs helps to set homeostatic levels of neutrophils via effects on the IL-23/IL-17/G-CSF cytokine axis, which stimulates neutrophil production in the bone marrow. However, the molecular events in phagocytes underlying this feedback loop have remained indeterminate. Liver X receptors (LXRs) are members of the nuclear receptor superfamily that regulate both lipid metabolic and inflammatory gene expression. Here, we demonstrate that LXRs contribute to the control of neutrophil homeostasis. Using gain- and loss-of-function models, we found that LXR signaling regulated the efficient clearance of senescent neutrophils by peripheral tissue APCs in a Mer-dependent manner. Furthermore, activation of LXR by engulfed neutrophils directly repressed the IL-23/IL-17/G-CSF granulopoietic cytokine cascade. These results provide mechanistic insight into the molecular events orchestrating neutrophil homeostasis and advance our understanding of LXRs as integrators of phagocyte function, lipid metabolism, and cytokine gene expression.
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103
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Locasale JW, Melman T, Song SS, Yang X, Swanson KD, Cantley LC, Asara JM, Wong ET, Adams S, Braidy N, Teo C, Guillemin G, Philippe M, Carole C, David T, Eric G, Isabelle NM, de Paula Andre M, Marylin B, Olivier C, L'Houcine O, Dominique FB, Leukel P, Seliger C, Vollmann A, Jachnik B, Bogdahn U, Hau P, Liu X, Kumar VS, McPherson CM, Chow L, Kendler A, Dasgupta B, Piya S, White E, Klein S, Jiang H, Lang F, Alfred Yung WK, Gomez-Manzano C, Fueyo J, Vartanian A, Guha A, Fenton KE, Abdelwahab M, Scheck AC, Guo D, Reinitz F, Youssef M, Hong C, Nathanson D, Akhavan D, Kuga D, Amzajerdi AN, Soto H, Zhu S, Babic I, Iwanami A, Tanaka K, Gini B, DeJesus J, Lisiero DD, Huang T, Prins R, Wen P, Robbins HI, Prados M, DeAngelis L, Mellinghoff I, Mehta M, James CD, Chakravarti A, Cloughesy T, Tontonoz P, Mischel P, Phillips J, Mukherjee J, Cowdrey C, Wiencke J, Pieper RO, Bachoo R, Marin-Valencia I, Cho S, Rakheja D, Hatanpaa K, Mashimo T, Vemireddy V, Kapur P, Good L, Sun X, Pascual J, Takahashi M, Togao O, Raisanen J, Maher EA, DeBerardinis R, Malloy C, Maher EA, Bachoo R, Marin-Valencia I, Hatanpaa K, Choi C, Mashimo T, Raisanen J, Mathews D, Pascual J, Madden C, Mickey B, Malloy C, DeBerardinis R, Mukherjee J, Zheng S, Phillips J, Cowdrey C, Ronen S, Wiencke J, Pieper RO, Park I, Jalbert LE, Ito M, Ozawa T, James CD, Phillips JJ, Vigneron DB, Pieper RO, Ronen SM, Nelson SJ. METABOLIC PATHWAYS. Neuro Oncol 2011; 13:iii69-iii72. [PMCID: PMC3199168 DOI: 10.1093/neuonc/nor153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/14/2023] Open
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104
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Jun-xian S, Jing-yi R, Guan-ping H, Hong C. Transient receptor potential vanilloid 1 is involved in the transfer of cardioprotection by remote limb ischemic postconditioning in rats. BRITISH HEART JOURNAL 2011. [DOI: 10.1136/heartjnl-2011-300867.237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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105
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Guan-ping H, Jun-xian S, Jing-yi R, Hong C. Dual activation of AKT kinase and STAT-3 kinase is involved in the cardioprotection by remote limb ischemic postconditionin in rats. BRITISH HEART JOURNAL 2011. [DOI: 10.1136/heartjnl-2011-300867.238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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106
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Xiu-Juan Z, Bang-Qing L, Jing-Yi R, Hong C. Diagnostic accuracy and influence factors of mutislice CT in women versus men with suspected or proven coronary artery disease. BRITISH HEART JOURNAL 2011. [DOI: 10.1136/heartjnl-2011-300867.412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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107
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Ceacareanu AC, Hong C, Brennan JJ, Epstein M, Kossoff E, Nimako GK, Patel K, Forrest A. Statin treatment use in diabetic patients with breast cancer: A potential C-reactive protein mediated benefit. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.27_suppl.173] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
173 Background: Statin treatment has not yet been evaluated in relation to breast cancer (BC) prognosis in diabetes mellitus (DM) patients. Reported decreased survival following BC in women with metabolic syndrome, led us to investigate whether specific statin therapy may lead to improved BC survival. Reported associations between elevated C-reactive protein (CRP) levels at the time of diagnosis with worse cancer prognosis, and CRP-lowering properties of statin treatment in non-cancer patients, led us to investigate whether statin use is associated with lower CRP levels at the time of BC diagnosis and with improved BC outcomes. Methods: All DM patients newly diagnosed with BC between 2003 and 2007 (Roswell Park Cancer Institute) were retrospectively reviewed (n = 225). BC pathology, outcomes, existing comorbidities and drug therapy were documented. Follow up began at BC diagnosis and ended with first confirmed recurrence and/or death, or last date of follow-up. Hazard ratios (HR) and 95% confidence intervals (CI)s representing the association between statins, BC and a defined event were computed with Cox proportional hazards model. CRP plasma levels were determined by enzyme-linked immunosorbent assay in specimens donated at the time of BC diagnosis. A total of 98 study patients, DM+BC, and their matched controls, BC only (n = 196) were analyzed. Results: After a median follow up of 30 months, patients receiving statins for cholesterol management were found to have better disease-free survival (HR 0.27, 95% CI: 0.10, 0.71, X2 = 7.31, p = 0.06), and lower overall mortality (HR 0.23, 95% CI: 0.08, 0.66, X2 = 7.80, p = 0.05) compared to patients not receiving any cholesterol management medication. CRP levels have ranged between 0.2 and 21 mg/L and clinically relevant levels ( > 3mg/L) were noted in the study group. Conclusions: This study explored for the first time the association between statin therapy and BC prognosis in DM. We observed improved outcomes in statin-treated patients. While we currently analyze statin therapy in relationship with baseline CRP levels and BC prognosis, our existing findings suggest that statins have the potential to improve BC outcomes potentially through lowering overall inflammation.
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Guo D, Reinitz F, Youssef M, Hong C, Nathanson D, Akhavan D, Kuga D, Amzajerdi AN, Soto H, Zhu S, Babic I, Tanaka K, Dang J, Iwanami A, Gini B, Dejesus J, Lisiero DD, Huang TT, Prins RM, Wen PY, Robins HI, Prados MD, Deangelis LM, Mellinghoff IK, Mehta MP, James CD, Chakravarti A, Cloughesy TF, Tontonoz P, Mischel PS. An LXR agonist promotes glioblastoma cell death through inhibition of an EGFR/AKT/SREBP-1/LDLR-dependent pathway. Cancer Discov 2011; 1:442-56. [PMID: 22059152 DOI: 10.1158/2159-8290.cd-11-0102] [Citation(s) in RCA: 310] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Glioblastoma (GBM) is the most common malignant primary brain tumor of adults and one of the most lethal of all cancers. Epidermal growth factor receptor (EGFR) mutations (EGFRvIII) and phosphoinositide 3-kinase (PI3K) hyperactivation are common in GBM, promoting tumor growth and survival, including through sterol regulatory element-binding protein 1 (SREBP-1)-dependent lipogenesis. The role of cholesterol metabolism in GBM pathogenesis, its association with EGFR/PI3K signaling, and its potential therapeutic targetability are unknown. In our investigation, studies of GBM cell lines, xenograft models, and GBM clinical samples, including those from patients treated with the EGFR tyrosine kinase inhibitor lapatinib, uncovered an EGFRvIII-activated, PI3K/SREBP-1-dependent tumor survival pathway through the low-density lipoprotein receptor (LDLR). Targeting LDLR with the liver X receptor (LXR) agonist GW3965 caused inducible degrader of LDLR (IDOL)-mediated LDLR degradation and increased expression of the ABCA1 cholesterol efflux transporter, potently promoting tumor cell death in an in vivo GBM model. These results show that EGFRvIII can promote tumor survival through PI3K/SREBP-1-dependent upregulation of LDLR and suggest a role for LXR agonists in the treatment of GBM patients.
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109
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Min D, Cho J, Hong C, Yoo T. UP-03.085 One Day Ureteral Catheter Placement after Ureteroscopic Lithotripsy: A Prospective Study. Urology 2011. [DOI: 10.1016/j.urology.2011.07.1175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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110
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Zhang L, Fairall L, Goult BT, Calkin AC, Hong C, Millard CJ, Tontonoz P, Schwabe JWR. The IDOL-UBE2D complex mediates sterol-dependent degradation of the LDL receptor. Genes Dev 2011; 25:1262-74. [PMID: 21685362 DOI: 10.1101/gad.2056211] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We previously identified the E3 ubiquitin ligase IDOL as a sterol-dependent regulator of the LDL receptor (LDLR). The molecular pathway underlying IDOL action, however, remains to be determined. Here we report the identification and biochemical and structural characterization of an E2-E3 ubiquitin ligase complex for LDLR degradation. We identified the UBE2D family (UBE2D1-4) as E2 partners for IDOL that support both autoubiquitination and IDOL-dependent ubiquitination of the LDLR in a cell-free system. NMR chemical shift mapping and a 2.1 Å crystal structure of the IDOL RING domain-UBE2D1 complex revealed key interactions between the dimeric IDOL protein and the E2 enzyme. Analysis of the IDOL-UBE2D1 interface also defined the stereochemical basis for the selectivity of IDOL for UBE2Ds over other E2 ligases. Structure-based mutations that inhibit IDOL dimerization or IDOL-UBE2D interaction block IDOL-dependent LDLR ubiquitination and degradation. Furthermore, expression of a dominant-negative UBE2D enzyme inhibits the ability of IDOL to degrade the LDLR in cells. These results identify the IDOL-UBE2D complex as an important determinant of LDLR activity, and provide insight into molecular mechanisms underlying the regulation of cholesterol uptake.
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111
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Ju S, Hong C, Han Y, Shin E, Shin J, Kim J, Park H, Huh W, Choi D. SU-E-T-504: Development of An Offline Based Internal Organ Motion Verification System during Treatment Using Sequential Cine EPID Images. Med Phys 2011. [DOI: 10.1118/1.3612457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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112
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Hong C, Ju S, Kim J, Shin J, Shin E, Han Y, Ahn Y, Park H, Choi D, Huh W. SU-E-T-263: Development of a Video Guided Real-Time Patient Motion Monitoring System. Med Phys 2011. [DOI: 10.1118/1.3612214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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113
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Sawant A, Hong C, Preston S, Joshi S. 1204 poster REAL-TIME MR IMAGING STRATEGIES FOR TRACKING MOVING AND DEFORMING LUNG TUMORS. Radiother Oncol 2011. [DOI: 10.1016/s0167-8140(11)71326-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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114
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Beaven SW, Wroblewski K, Wang J, Hong C, Bensinger S, Tsukamoto H, Tontonoz P. Liver X receptor signaling is a determinant of stellate cell activation and susceptibility to fibrotic liver disease. Gastroenterology 2011; 140:1052-62. [PMID: 21134374 PMCID: PMC3049833 DOI: 10.1053/j.gastro.2010.11.053] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2010] [Revised: 11/14/2010] [Accepted: 11/22/2010] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS Liver X receptors (LXRs) are lipid-activated nuclear receptors with important roles in cholesterol transport, lipogenesis, and anti-inflammatory signaling. Hepatic stellate cells activate during chronic liver injury and mediate the fibrotic response. These cells are also major repositories for lipids, but the role of lipid metabolism during stellate cell activation remains unclear. We investigated the role of LXR signaling stellate cell activation and susceptibility to fibrotic liver disease. METHODS Immortalized and primary stellate cells purified from mice were treated with highly specific LXR ligands. Carbon tetrachloride and methionine/choline deficiency were used as chronic liver injury models. Reciprocal bone marrow transplants were performed to test the importance of hematopoietically derived cells to the fibrotic response. RESULTS LXR ligands suppressed markers of fibrosis and stellate cell activation in primary mouse stellate cells. Lxrαβ(-/-) stellate cells produce increased levels of inflammatory mediators, and conditioned media from Lxrαβ(-/-) cells increases the fibrogenic program of wild-type cells. Furthermore, Lxrαβ(-/-) stellate cells exhibit altered lipid morphology and increased expression of fibrogenic genes, suggesting they are primed for activation. In vivo, Lxrαβ(-/-) mice have marked susceptibility to fibrosis in 2 injury models. Bone marrow transplants point to altered stellate cell function, rather than hematopoietic cell inflammation, as the primary basis for the Lxrαβ(-/-) phenotype. CONCLUSIONS These results reveal an unexpected role for LXR signaling and lipid metabolism in the modulation of hepatic stellate cell function.
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115
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Feig JE, Pineda-Torra I, Sanson M, Bradley MN, Vengrenyuk Y, Bogunovic D, Gautier EL, Rubinstein D, Hong C, Liu J, Wu C, van Rooijen N, Bhardwaj N, Garabedian M, Tontonoz P, Fisher EA. LXR promotes the maximal egress of monocyte-derived cells from mouse aortic plaques during atherosclerosis regression. J Clin Invest 2011; 120:4415-24. [PMID: 21041949 DOI: 10.1172/jci38911] [Citation(s) in RCA: 150] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Accepted: 09/15/2010] [Indexed: 12/20/2022] Open
Abstract
We have previously shown that mouse atherosclerosis regression involves monocyte-derived (CD68+) cell emigration from plaques and is dependent on the chemokine receptor CCR7. Concurrent with regression, mRNA levels of the gene encoding LXRalpha are increased in plaque CD68+ cells, suggestive of a functional relationship between LXR and CCR7. To extend these results, atherosclerotic Apoe-/- mice sufficient or deficient in CCR7 were treated with an LXR agonist, resulting in a CCR7-dependent decrease in plaque CD68+ cells. To test the requirement for LXR for CCR7-dependent regression, we transplanted aortic arches from atherosclerotic Apoe-/- mice, or from Apoe-/- mice with BM deficiency of LXRalpha or LXRbeta, into WT recipients. Plaques from both LXRalpha and LXRbeta-deficient Apoe-/- mice exhibited impaired regression. In addition, the CD68+ cells displayed reduced emigration and CCR7 expression. Using an immature DC line, we found that LXR agonist treatment increased Ccr7 mRNA levels. This increase was blunted when LXRalpha and LXRbeta levels were reduced by siRNAs. Moreover, LXR agonist treatment of primary human immature DCs resulted in functionally significant upregulation of CCR7. We conclude that LXR is required for maximal effects on plaque CD68+ cell expression of CCR7 and monocyte-derived cell egress during atherosclerosis regression in mice.
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116
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Hong C, Walczak R, Dhamko H, Bradley MN, Marathe C, Boyadjian R, Salazar JV, Tontonoz P. Constitutive activation of LXR in macrophages regulates metabolic and inflammatory gene expression: identification of ARL7 as a direct target. J Lipid Res 2010; 52:531-9. [PMID: 21187453 PMCID: PMC3035689 DOI: 10.1194/jlr.m010686] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Ligand activation of liver X receptors (LXRs) has been shown to impact both lipid metabolism and inflammation. One complicating factor in studies utilizing synthetic LXR agonists is the potential for pharmacologic and receptor-independent effects. Here, we describe an LXR gain-of-function system that does not depend on the addition of exogenous ligand. We generated transgenic mice expressing a constitutively active VP16-LXRα protein from the aP2 promoter. These mice exhibit increased LXR signaling selectively in adipose and macrophages. Analysis of gene expression in primary macrophages derived from two independent VP16-LXRα transgenic lines confirmed the ability of LXR to drive expression of genes involved in cholesterol efflux and fatty acid synthesis. Moreover, VP16-LXRα expression also suppressed the induction of inflammatory genes by lipopolysaccharide to a comparable degree as synthetic agonist. We further utilized VP16-LXRα-expressing macrophages to identify and validate new targets for LXRs, including the gene encoding ADP-ribosylation factor-like 7 (ARL7). ARL7 has previously been shown to transport cholesterol to the membrane for ABCA1-associated removal and thus may be integral to the LXR-dependent efflux pathway. We show that the ARL7 promoter contains a functional LXRE and can be transactivated by LXRs in a sequence-specific manner, indicating that ARL7 is a direct target of LXR. These findings provide further support for an important role of LXRs in the coordinated regulation of lipid metabolic and inflammatory gene programs in macrophages.
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117
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Fang-Fang Z, Fang-Fang Z, Hong C. e0028 The effect of acute activation of ALDH2 on myocardial ischaemia/reperfusion injury in rat. BRITISH HEART JOURNAL 2010. [DOI: 10.1136/hrt.2010.208967.28] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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118
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Jun-Xian S, Hong C. e0063 Cardioprotection by ischaemic preconditioning is lost in isolated diabetic hearts: role of transient receptor potential vanilloid 1. BRITISH HEART JOURNAL 2010. [DOI: 10.1136/hrt.2010.208967.63] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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119
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Hong C, Fang-fang Z. e0371 The effect of ALDH2 genetic polymorphism on myocardial ischaemia reperfusion injury in Chinese. BRITISH HEART JOURNAL 2010. [DOI: 10.1136/hrt.2010.208967.371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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120
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Ying C, Hong C. e0430 Highsensitivity Creactive protein levels at admission can not be used to predict inhospital mortality in patients with acute myocardial infarction a retrospective study. BRITISH HEART JOURNAL 2010. [DOI: 10.1136/hrt.2010.208967.430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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121
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Hong C, Sawant A, Keall P. TU-D-204B-09: Rapid MR Imaging for Real-Time Target Tracking Using Temporal Sparsity. Med Phys 2010. [DOI: 10.1118/1.3469267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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122
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Hong C, Duit S, Jalonen P, Out R, Scheer L, Sorrentino V, Boyadjian R, Rodenburg KW, Foley E, Korhonen L, Lindholm D, Nimpf J, van Berkel TJC, Tontonoz P, Zelcer N. The E3 ubiquitin ligase IDOL induces the degradation of the low density lipoprotein receptor family members VLDLR and ApoER2. J Biol Chem 2010; 285:19720-6. [PMID: 20427281 PMCID: PMC2888382 DOI: 10.1074/jbc.m110.123729] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have previously identified the E3 ubiquitin ligase-inducible degrader of the low density lipoprotein receptor (LDLR) (Idol) as a post-translational modulator of LDLR levels. Idol is a direct target for regulation by liver X receptors (LXRs), and its expression is responsive to cellular sterol status independent of the sterol-response element-binding proteins. Here we demonstrate that Idol also targets two closely related LDLR family members, VLDLR and ApoE receptor 2 (ApoER2), proteins implicated in both neuronal development and lipid metabolism. Idol triggers ubiquitination of the VLDLR and ApoER2 on their cytoplasmic tails, leading to their degradation. We further show that the level of endogenous VLDLR is sensitive to cellular sterol content, Idol expression, and activation of the LXR pathway. Pharmacological activation of the LXR pathway in mice leads to increased Idol expression and to decreased Vldlr levels in vivo. Finally, we establish an unexpected functional link between LXR and Reelin signaling. We demonstrate that LXR activation results in decreased Reelin binding to VLDLR and reduced Dab1 phosphorylation. The identification of VLDLR and ApoER2 as Idol targets suggests potential roles for this LXR-inducible E3 ligase in the central nervous system in addition to lipid metabolism.
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123
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Hong C, Seetzen H, Burton AM, Chaudhuri A. Face recognition is robust against incongruent image resolution. J Vis 2010. [DOI: 10.1167/2.7.610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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124
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Kim D, Al-Dawsari G, Jung C, Hong C, Kamel-Reid S, Galal A, Gupta V, Kuruvilla J, Lipton J, Messner H. Clinical Relevance Of Large Granular Lymphocyte Expansion Following Allogeneic Hematopoietic Stem Cell Transplantation With HLA Identical Sibling Donors. Biol Blood Marrow Transplant 2010. [DOI: 10.1016/j.bbmt.2009.12.217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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125
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Akimoto T, Kim K, Yamauchi R, Izawa S, Hong C, Aizawa K, Lee H, Suzuki K. Exercise in, and adaptations to a cold environment have no effect on SIgA. J Sports Med Phys Fitness 2009; 49:315-319. [PMID: 19861939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
AIM The authors hypothesized that inconsistent SIgA response to exercise is caused by the different adaptative status of subjects to a cold environment. The purposes of the study were to examine whether moderate-intense exercise in a cold environment decreases SIgA and whether adaptation to a cold environment has any effect on SIgA. METHODS Young male skaters, short track (N=9) and inline (N=10), participated in this study. All subjects cycled for 60 min at 65% VO(2max) in cold (ambient temperature: 5 +or - 1 degrees Celsius, relative humidity 41 + or - 9%) and thermoneutral (ambient temperature: 21 + or - 1 degrees Celsius, relative humidity 35 + or - 5%) conditions. Saliva samples were collected as follows: before and after 1hour of environmental exposure; immediately, 30-min, 60-min and 120-min after the exercise. RESULTS AND CONCLUSIONS Salivary SIgA and saliva flow rate decreased after the exercise in both groups only in thermoneutral conditions. The SIgA secretion rate did not decrease after moderate-high intensity exercise in a cold environment, and the SIgA response to exercise was not affected by the different adaptative status of subjects to the cold environment.
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