DOCSLIB.ORG

Down-Regulation of ATP-Binding Cassette Transporter G1 Expression by Unmethylated Cpg Oligodeoxynucleotides in RAW 264.7 Macrophages

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Down-Regulation of ATP-Binding Cassette Transporter G1 Expression by Unmethylated Cpg Oligodeoxynucleotides in RAW 264.7 Macrophages EXPERIMENTAL and MOLECULAR MEDICINE, Vol. 43, No. 9, 510-516, September 2011 Down-regulation of ATP-binding cassette transporter G1 expression by unmethylated CpG oligodeoxynucleotides in RAW 264.7 macrophages Jeong Min Seo1, Ji-Young Lee2, Geun Eog Ji3 of ABCG1 protein expression by CpG 2006. In addition, and Ji Chang You1,4 we also determined the protein level of peroxisome proliferator activated receptor γ (PPARγ), which is rec- 1National Research Laboratory of Molecular Virology ognized as a transcriptional activator of ABC trans- Department of Pathology porters, was also reduced by CpG 2006. Thus, these re- The Catholic University of Korea, School of Medicine sults suggest that ABCG1 is specifically down-regu- Seoul 137-701, Korea lated by CpG 2006 in a PPARγ-dependent manner in 2Department of Nutritional Sciences macrophages. University of Connecticut Storrs CT 06269, USA Keywords: atherosclerosis; ATP-binding cassette 3Department of Food and Nutrition transpoters; cholesterol; CpG oligonucleotide; macro- Research Institute of Human Ecology phages Seoul National University Seoul 151-742, Korea 4Corresponding author: Tel, 82-2-2258-7312; Introduction Fax, 82-2-2258-7790; E-mail, [email protected] http://dx.doi.org/10.3858/emm.2011.43.9.058 All plants and animals, including humans, have in- nate defense systems for protection against viral Accepted 6 July 2011 and bacterial invasions. The innate immune sys- Available Online 8 July 2011 tem is initiated by pattern recognition molecules (PRMs) that recognize pathogen-associated mo- Abbreviations: ABCA1, ATP-binding cassette transporter A1; lecular patterns (PAMPs) such as peptidoglycan, ABCG1, ATP-binding cassette transporter G1; CpG ODN, lipopolysaccharide (LPS), and unmethylated cyti- cytidine-phosphate-guanosine oligodeoxynucleotide; LXRα, dine-phosphate-guanosine (CpG) DNA. Recent liver X receptor α; PO, phosphodiester; PPARγ, peroxisome studies have demonstrated that immunostimulation proliferator activated receptor γ; PS, phosphorothioate; TLR, can be induced through toll-like receptor 9 (TLR9) toll-like receptor by synthetic CpG oligodeoxynucleotides (CpG ODNs) as well as bacterial DNA. To date, many studies have demonstrated that synthetic CpG Abstract ODNs containing ‘CpG motifs’ are able to activate dendritic cells, natural killer (NK) cells, monocytes, We have investigated the effect of various forms of macrophages and B cells, inducing the release phosphodiester cytidine-phosphate-guanosine oli- and secretion of various cytokines and immuno- godeoxynucleotides (CpG ODNs) on the production of globulins (Krieg, 1995; Krug et al., 2001; Iwasaki pro-inflammatory cytokines and related genes in RAW and Medzhitov, 2004; Blaas et al., 2009; El Kebir et 264.7 macrophages. Treatment with the CpG ODNs in- al., 2009; Mangsbo et al., 2009; Vollmer et al., creased the expression of tumor necrosis factor α 2009). Lately, it has been being also reported that (TNF-α), IL-6, and inducible nitric oxide synthase but TLRs and their signaling cascades are involved in not interleukin-1β (IL-1β). We also investigated the ef- the perpetuation of a chronic inflammatory milieu that characterizes obesity and high fat feeding fect of CpG ODNs on the expression of ATP-binding (Shoelson et al., 2007; Ajuwon et al., 2009). For cassette transporter A1 (ABCA1) and G1 (ABCG1) these reasons, safety concerns might be raised genes which are known to facilitate cholesterol efflux concerning the use of CpG ODNs as therapeutic from macrophages for anti-atherosclerosis. CpG 2006 agents for patients with diabetes and inflammatory significantly reduced the levels of ABCG1 mRNA as de- arthritis as well as atherosclerosis (Zeuner et al., termined by real-time polymerase chain reaction, 2003). whereas ABCA1 mRNA level was not changed. It has been reported that macrophages may play Western blot analysis further confirmed the reduction a major role in atherosclerosis (Davies, 1996). Down-regulation of ABCG1 by CpG ODNs 511 When the function of macrophages is not properly controlled, they can trigger low-grade inflammation in the artery by producing various pro-inflammatory cytokines, chemokines and enzymes that amplify the progression of atherosclerosis. In addition to eliciting chronic low-grade inflammation, macro- phages are involved in the pathological deposition of cholesterol during atherogenesis as a result of the uptake of modified low-density lipoproteins (LDLs) (van Reyk and Jessup, 1999). Macrophages with cholesterol accumulation become foam cells, a hallmark of the early atherosclerotic lesion (Rigamonti et al., 2008). ATP-binding cassette trans- porter A1 (ABCA1) and G1 (ABCG1) are known to facilitate cholesterol efflux from macrophages to ex- tracellular acceptors such as lipid-free apolipopro- tein A-I (apoA-I) and high-density lipoprotein (HDL). The ability of apoA-I and HDL to stimulate cholesterol efflux from macrophages in the arterial wall represents the first step in reverse cholesterol transport (RCT), a process that transports excess cholesterol from the periphery to the liver for ulti- mate excretion from the body. The role of HDL in the RCT is central to its anti-atherogenic effects (Tall et al., 2008). ABCG1 was recently shown to be capable of mediating an active efflux of cholesterol Figure 1. Expression of pro-inflammatory cytokine, TNF-α induced by and phospholipids in macrophages (Brewer et al., TLR9 agonist CpG ODNs in RAW 264.7 cells. Cells were incubated with or without CpG ODNs for 12 and 24 h. Supernatants were recovered for 2003). each time point and assayed for TNF-α protein secretion by ELISA. (A) In this study, we hypothesized if CpG ODNs Cells were treated with each CpG ODN (15 μmol/ml) for 12 h to evaluate could be involved in regulating the expression of the effects on TNF-α compared with untreated (mock) and CpG 2006(-) ABCA1 or ABCG1 in macrophages, as little is known controls. (B-D) Cells were treated with CpG 1826, which include murine CpG motifs, and CpG 2006 which includes human CpG motifs. The CpG about the regulation of ABC transporter genes by ODNs induced secretion of TNF-α in a time- and dose-dependent CpG ODN. Therefore, we investigated the effec- manner. Values are means ± standard error of the mean (SEM; n = 6). tiveness of CpG ODNs in a phosphodiester form Bars with different letters are significantly different (P ＜ 0.05). (PO-ODNs), to be more biologically relevant, in the modulation of ABCA1 and ABCG1 gene ex- pression as well as in inducing various pro-in- virus-originated CpG ODN (virus CpG), and CpG flammatory cytokine production in RAW 264.7 mur- 1826 all showed a significant increase in TNF-α ine macrophages. secretion, compared to the mock and CpG 2006 (-) (Figure 1A). Among the CpG ODNs that were used in this study, CpG 2006 had the greatest effect on Results TNF-α production in RAW264.7 macrophages and PE2059 showed an effect similar to that of CpG Immuno-stimulatory effect of natural PO-formed 2006. Compared with PE2059, CpG2006 has one CpG ODNs additional nucleotide, T, at the 3'-terminus. In order to verify first the effectiveness of the CpG The fact that CpG 2006, which contains human ODNs used in this study in inducing alledgedly CpG motif sequences GTCGTT, showed a strong known pro-inflammatory cytokines, RAW 264.7 immuno-stimulatory effect even in murine macro- macrophage cells were treated with various CpG phages is consistent with previous findings ob- ODNs (15 μg/ml) for 12 h, along with a negative served with phosphorothioate-modified ODNs (PS- control CpG 2006 (-) and an untreated control ODNs) in primary B cell and isolated murine car- (mock) (Figure 1A). The tumor necrosis factor diomyocytes (Hartmann and Krieg, 2000; Hartmann (TNF)-α concentration in media after the treatment et al., 2000; Knuefermann et al., 2008). Of noted was measured using an enzyme-linked im- interestingly, CpG 2006 elicited a significantly high- munosorvent assay (ELISA). The results showed er pro-inflammatory response than that of CpG that macrophages treated with CpG 2006, PE2059, 1826 which is generally recognized as a murine 512 Exp. Mol. Med. Vol. 43(9), 510-516, 2011 Figure 2. Comparison of TNF-α and IL-1β induction by CpG 1826 and CpG 2006. Both CpG 1826 and CpG 2006 up-regulated TNF-α sig- nificantly but did not alter IL-1β levels compared to LPS (positive control). Cells were treated with 10 μg/ml of each CpG ODN or 0.1 μg/ml LPS for 24 h. Supernatants were recovered and assayed for the secretion of TNF-α (A) and IL-1β (B) by ELISA. CpG ODN. It was observed that CpG 2006 had a more prominent effect on TNF-α production than CpG 1826 for both cases of 12 h and 24 h treat- ments (Figures 1A-1D); the immunostimulatory ef- fect of CpG 2006 was 61.4 % higher than that of CpG 1826 for 24-h treatment at a concentration of Figure 3. Transcriptional modulation of pro-inflammatory genes by CpG 1826 and CpG 2006. CpG 1826 and CpG 2006 induced mRNA levels of 15 μg/ml (Figure 1B). In addition, a 24-h treatment TNF-α (A), IL-6 (B), and iNOS (C). In contrast, the CpG ODNs did not with CpG 2006 ODN (10 μg/ml) (Figure 1D) up-regulate the mRNA level of IL-1β significantly (D). The mRNA levels of showed further induction of TNF-α than a 12-h the indicated genes were quantified by real-time RT-PCR after treating treatment (Figure 1C). Thus, these results demon- macrophages with 10 μg/ml of each CpG ODN or 0.1 μg/ml LPS for 12 h. strate clearly that PO CpG 2006 is able to increase TNF-α expression in a dose- and time-dependent manner and is superior to CpG 1826 for that matter comparison. RAW 264.7 macrophages were in- in RAW 264.7 macrophage cells. cubated with CpG 1826 or CpG 2006 for 12 h, and We also compared the same immunostimulatory the pro-inflammatory genes TNF-α, IL-6 were eval- effect of CpG ODNs with that of LPS at a concen- uated by quantitative real-time PCR (RT qPCR).
Load more

Recommended publications
  • The Pharmacogenomics of Vincristine-Induced Neurotoxicity
    THE PHARMACOGENOMICS OF VINCRISTINE-INDUCED NEUROTOXICITY IN PAEDIATRIC CANCER PATIENTS WITH WILMS TUMOR OR RHABDOMYOSARCOMA by Tenneille Loo A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE STUDIES (Experimental Medicine) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) July 2011 © Tenneille Loo, 2011 Abstract Vincristine is one of the most effective and widely utilized antineoplastic agents. However, the clinical utility of this drug is limited by severely debilitating vincristine- induced neurotoxicities (VIN). Previous studies have associated VIN with genetic polymorphisms in genes involved in the metabolism and transportation of vincristine, including CYP3A4, CYP3A5, and ABCB1. However, the findings of such studies have not been consistently reproduced. This study hypothesizes that there are specific variants in genes involved in general drug absorption, metabolism, distribution, excretion, and toxicity (ADME-Tox) that affect the individual susceptibility to VIN in patients with Wilms tumor and rhabdomyosarcoma. Detailed clinical data was collected from 140 patients with Wilms tumor and rhabdomyosarcoma by retrospective chart review. VIN cases were characterized by type of neurotoxicity, and severity was evaluated using a validated clinical grading system for adverse events (NCI-CTCAE v4.03). A customized Illumina GoldenGate Panel was used to genotype 4,536 single nucleotide polymorphisms (SNPs) in candidate genes involved in the metabolism and transportation pathway of vincristine, as well as in genes broadly involved in ADME-Tox. None of the SNPs that were previously reported to be associated with VIN were found to be significantly associated (p-value < 0.05). With similar effect sizes, six novel genetic variants in five genes (PON1, ABCA4, ABCG1, CY51A1, SLCO1C1) were significantly associated with VIN in both tumor types.
    [Show full text]
  • ABCG1 (ABC8), the Human Homolog of the Drosophila White Gene, Is a Regulator of Macrophage Cholesterol and Phospholipid Transport
    ABCG1 (ABC8), the human homolog of the Drosophila white gene, is a regulator of macrophage cholesterol and phospholipid transport Jochen Klucken*, Christa Bu¨ chler*, Evelyn Orso´ *, Wolfgang E. Kaminski*, Mustafa Porsch-Ozcu¨ ¨ ru¨ mez*, Gerhard Liebisch*, Michael Kapinsky*, Wendy Diederich*, Wolfgang Drobnik*, Michael Dean†, Rando Allikmets‡, and Gerd Schmitz*§ *Institute for Clinical Chemistry and Laboratory Medicine, University of Regensburg, 93042 Regensburg, Germany; †National Cancer Institute, Laboratory of Genomic Diversity, Frederick, MD 21702-1201; and ‡Departments of Ophthalmology and Pathology, Columbia University, Eye Research Addition, New York, NY 10032 Edited by Jan L. Breslow, The Rockefeller University, New York, NY, and approved November 3, 1999 (received for review June 14, 1999) Excessive uptake of atherogenic lipoproteins such as modified low- lesterol transport. Although several effector molecules have been density lipoprotein complexes by vascular macrophages leads to proposed to participate in macrophage cholesterol efflux (6, 9), foam cell formation, a critical step in atherogenesis. Cholesterol efflux including endogenous apolipoprotein E (10) and the cholesteryl mediated by high-density lipoproteins (HDL) constitutes a protective ester transfer protein (11), the detailed molecular mechanisms mechanism against macrophage lipid overloading. The molecular underlying cholesterol export in these cells have not yet been mechanisms underlying this reverse cholesterol transport process are characterized. currently not fully understood. To identify effector proteins that are Recently, mutations of the ATP-binding cassette (ABC) trans- involved in macrophage lipid uptake and release, we searched for porter ABCA1 gene have been causatively linked to familial HDL genes that are regulated during lipid influx and efflux in human deficiency and Tangier disease (12–14).
    [Show full text]
  • Ligand, Receptor, and Cell Type–Dependent Regulation of ABCA1 and ABCG1 Mrna in Prostate Cancer Epithelial Cells
    Published OnlineFirst June 16, 2009; DOI: 10.1158/1535-7163.MCT-09-0020 Published Online First on June 16, 2009 as 10.1158/1535-7163.MCT-09-0020 OF1 Ligand, receptor, and cell type–dependent regulation of ABCA1 and ABCG1 mRNA in prostate cancer epithelial cells Steven E. Trasino,1 Young S. Kim,2 that ABCA1 gene expression is differentially regulated by and Thomas T.Y. Wang1 synthetic and natural LXR ligands, possibly involving kinase mediated signal transduction. [Mol Cancer Ther 2009;8(7): 1 Diet, Genomics, and Immunology Laboratory, Beltsville Human OF1–12] Nutrition Research Center, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland and 2Nutritional Sciences Research Group, Division of Cancer Introduction Prevention, National Cancer Institute, NIH, Bethesda, Maryland Advanced and metastatic prostate cancer (PCa) remains the most prominent cancer type and the second leading cause of Abstract all cancer deaths among males in the United States (1). Recent evidence suggests that the liver X receptor (LXR) Treatment of recurrent or advanced PCa with hormone ab- is a potential anticancer target in prostate carcinoma. lation therapy typically results in disease regression with There is little characterization, however, of which of the eventual recurrence of PCa with a more aggressive and two LXR isoforms, LXRα or LXRβ, regulates the LXR- untreatable phenotype (2). In the absence of any effective responsive genes ATP-binding cassette subfamily members long-term therapy and with such an overwhelming social A1 (ABCA1)andG1(ABCG1) in transformed prostatic ep- burden, characterization of novel targets for effective che- ithelial cells. In this study, small interfering RNA (siRNA) moprevention or treatment of PCa has been a priority for α β cancer researchers.
    [Show full text]
  • Overall and Sex-Specific Associations Between Methylation of the ABCG1
    Qin et al. Clinical Epigenetics (2019) 11:189 https://doi.org/10.1186/s13148-019-0784-0 RESEARCH Open Access Overall and sex-specific associations between methylation of the ABCG1 and APOE genes and ischemic stroke or other atherosclerosis-related traits in a sibling study of Chinese population Xueying Qin1*† , Jin Li1, Tao Wu1, Yiqun Wu1, Xun Tang1, Pei Gao1, Lin Li2, Mengying Wang1, Yao Wu1, Xiaowen Wang1, Dafang Chen1 and Yonghua Hu1*† Abstract Background: Identifying subjects with a high risk of ischemic stroke is fundamental for prevention of the disease. Both genetic and environmental risk factors contribute to ischemic stroke, but the underlying epigenetic mechanisms which mediate genetic and environmental risk effects are not fully understood. The aim of this study was to explore whether DNA methylation loci located in the ATP-binding cassette G1 (ABCG1) and apolipoprotein E (APOE)genes, both involved in the metabolism of lipids in the body, are related to ischemic stroke, using the Fangshan/Family-based Ischemic Stroke Study in China. We also tested if these CpG sites were associated with early signs of cardiovascular atherosclerosis (carotid intima–media thickness (cIMT), ankle–brachial index (ABI), and brachial–ankle pulse wave velocity (baPWV)). Results: DNA methylation at the cg02494239 locus in ABCG1 was correlated with ischemic stroke after adjusting for gender, previous history of diabetes and hypertension, smoking, drinking, body mass index, and blood lipid levels (above vs below mean, OR = 2.416, 95% CI 1.024–5.700, P =0.044;75–100% percentile vs 0–25% percentile, OR = 4.461, 95% CI 1.226–16.225, P = 0.023).
    [Show full text]
  • Interindividual Differences in the Expression of ATP-Binding
    Supplemental material to this article can be found at: http://dmd.aspetjournals.org/content/suppl/2018/02/02/dmd.117.079061.DC1 1521-009X/46/5/628–635$35.00 https://doi.org/10.1124/dmd.117.079061 DRUG METABOLISM AND DISPOSITION Drug Metab Dispos 46:628–635, May 2018 Copyright ª 2018 by The American Society for Pharmacology and Experimental Therapeutics Special Section on Transporters in Drug Disposition and Pharmacokinetic Prediction Interindividual Differences in the Expression of ATP-Binding Cassette and Solute Carrier Family Transporters in Human Skin: DNA Methylation Regulates Transcriptional Activity of the Human ABCC3 Gene s Tomoki Takechi, Takeshi Hirota, Tatsuya Sakai, Natsumi Maeda, Daisuke Kobayashi, and Ichiro Ieiri Downloaded from Department of Clinical Pharmacokinetics, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan (T.T., T.H., T.S., N.M., I.I.); Drug Development Research Laboratories, Kyoto R&D Center, Maruho Co., Ltd., Kyoto, Japan (T.T.); and Department of Clinical Pharmacy and Pharmaceutical Care, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan (D.K.) Received October 19, 2017; accepted January 30, 2018 dmd.aspetjournals.org ABSTRACT The identification of drug transporters expressed in human skin and levels. ABCC3 expression levels negatively correlated with the methylation interindividual differences in gene expression is important for understanding status of the CpG island (CGI) located approximately 10 kilobase pairs the role of drug transporters in human skin. In the present study, we upstream of ABCC3 (Rs: 20.323, P < 0.05). The reporter gene assay revealed evaluated the expression of ATP-binding cassette (ABC) and solute carrier a significant increase in transcriptional activity in the presence of CGI.
    [Show full text]
  • ABCA7 and Pathogenic Pathways of Alzheimer's Disease
    brain sciences Review ABCA7 and Pathogenic Pathways of Alzheimer’s Disease Tomonori Aikawa, Marie-Louise Holm ID and Takahisa Kanekiyo * Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA; [email protected] (T.A.); [email protected] (M.-L.H.) * Correspondence: [email protected]; Tel.: +1-904-953-2483 Received: 28 December 2017; Accepted: 3 February 2018; Published: 5 February 2018 Abstract: The ATP-binding cassette (ABC) reporter family functions to regulate the homeostasis of phospholipids and cholesterol in the central nervous system, as well as peripheral tissues. ABCA7 belongs to the A subfamily of ABC transporters, which shares 54% sequence identity with ABCA1. While ABCA7 is expressed in a variety of tissues/organs, including the brain, recent genome-wide association studies (GWAS) have identified ABCA7 gene variants as susceptibility loci for late-onset Alzheimer’s disease (AD). More important, subsequent genome sequencing analyses have revealed that premature termination codon mutations in ABCA7 are associated with the increased risk for AD. Alzheimer’s disease is a progressive neurodegenerative disease and the most common cause of dementia, where the accumulation and deposition of amyloid-β (Aβ) peptides cleaved from amyloid precursor protein (APP) in the brain trigger the pathogenic cascade of the disease. In consistence with human genetic studies, increasing evidence has demonstrated that ABCA7 deficiency exacerbates Aβ pathology using in vitro and in vivo models. While ABCA7 has been shown to mediate phagocytic activity in macrophages, ABCA7 is also involved in the microglial Aβ clearance pathway. Furthermore, ABCA7 deficiency results in accelerated Aβ production, likely by facilitating endocytosis and/or processing of APP.
    [Show full text]
  • Ohnologs in the Human Genome Are Dosage Balanced and Frequently Associated with Disease
    Ohnologs in the human genome are dosage balanced and frequently associated with disease Takashi Makino1 and Aoife McLysaght2 Smurfit Institute of Genetics, University of Dublin, Trinity College, Dublin 2, Ireland Edited by Michael Freeling, University of California, Berkeley, CA, and approved April 9, 2010 (received for review December 21, 2009) About 30% of protein-coding genes in the human genome are been duplicated by WGD, subsequent loss of individual genes related through two whole genome duplication (WGD) events. would result in a dosage imbalance due to insufficient gene Although WGD is often credited with great evolutionary impor- product, thus leading to biased retention of dosage-balanced tance, the processes governing the retention of these genes and ohnologs. In fact, evidence for preferential retention of dosage- their biological significance remain unclear. One increasingly pop- balanced genes after WGD is accumulating (4, 7, 11–20). Copy ular hypothesis is that dosage balance constraints are a major number variation [copy number polymorphism (CNV)] describes determinant of duplicate gene retention. We test this hypothesis population level polymorphism of small segmental duplications and show that WGD-duplicated genes (ohnologs) have rarely and is known to directly correlate with gene expression levels (21– experienced subsequent small-scale duplication (SSD) and are also 24). Thus, CNV of dosage-balanced genes is also expected to be refractory to copy number variation (CNV) in human populations deleterious. This model predicts that retained ohnologs should be and are thus likely to be sensitive to relative quantities (i.e., they are enriched for dosage-balanced genes that are resistant to sub- dosage-balanced).
    [Show full text]
  • Hedgehog-GLI Signalling Promotes Chemoresistance Through The
    www.nature.com/scientificreports OPEN Hedgehog‑GLI signalling promotes chemoresistance through the regulation of ABC transporters in colorectal cancer cells Agnese Po1, Anna Citarella1, Giuseppina Catanzaro2, Zein Mersini Besharat2, Sofa Trocchianesi1, Francesca Gianno1, Claudia Sabato2, Marta Moretti2, Enrico De Smaele2, Alessandra Vacca2, Micol Eleonora Fiori3 & Elisabetta Ferretti2,4* Colorectal cancer (CRC) is a leading cause of cancer death. Chemoresistance is a pivotal feature of cancer cells leading to treatment failure and ATP-binding cassette (ABC) transporters are responsible for the efux of several molecules, including anticancer drugs. The Hedgehog-GLI (HH-GLI) pathway is a major signalling in CRC, however its role in chemoresistance has not been fully elucidated. Here we show that the HH-GLI pathway favours resistance to 5-fuorouracil and Oxaliplatin in CRC cells. We identifed potential GLI1 binding sites in the promoter region of six ABC transporters, namely ABCA2, ABCB1, ABCB4, ABCB7, ABCC2 and ABCG1. Next, we investigated the binding of GLI1 using chromatin immunoprecipitation experiments and we demonstrate that GLI1 transcriptionally regulates the identifed ABC transporters. We show that chemoresistant cells express high levels of GLI1 and of the ABC transporters and that GLI1 inhibition disrupts the transporters up-regulation. Moreover, we report that human CRC tumours express high levels of the ABCG1 transporter and that its expression correlates with worse patients’ prognosis. This study identifes a new mechanism where HH‑GLI signalling regulates CRC chemoresistance features. Our results indicate that the inhibition of Gli1 regulates the ABC transporters expression and therefore should be considered as a therapeutic option in chemoresistant patients. Colorectal cancer (CRC) is a leading cause of cancer-related death worldwide and is characterized by resistance mechanisms that lead to disease progression 1.
    [Show full text]
  • Rosmarinic Acid Increases Macrophage Cholesterol Efflux
    International Journal of Molecular Sciences Article Rosmarinic Acid Increases Macrophage Cholesterol Efflux through Regulation of ABCA1 and ABCG1 in Different Mechanisms Jean-Baptiste Nyandwi 1,2,3 , Young Shin Ko 1, Hana Jin 1, Seung Pil Yun 1, Sang Won Park 1,2 and Hye Jung Kim 1,2,* 1 Department of Pharmacology, Institute of Health Sciences, College of Medicine, Gyeongsang National University, Jinju 52727, Korea; [email protected] (J.-B.N.); [email protected] (Y.S.K.); [email protected] (H.J.); [email protected] (S.P.Y.); [email protected] (S.W.P.) 2 Department of Convergence Medical Science (BK21 Plus), Gyeongsang National University, Jinju 52727, Korea 3 Department of Pharmacy, School of Medicine and Pharmacy, College of Medicine and Health Sciences, University of Rwanda, Kigali 4285, Rwanda * Correspondence: [email protected] Abstract: Lipid dysregulation in diabetes mellitus escalates endothelial dysfunction, the initial event in the development and progression of diabetic atherosclerosis. In addition, lipid-laden macrophage accumulation in the arterial wall plays a significant role in the pathology of diabetes-associated atherosclerosis. Therefore, inhibition of endothelial dysfunction and enhancement of macrophage cholesterol efflux is the important antiatherogenic mechanism. Rosmarinic acid (RA) possesses benefi- cial properties, including its anti-inflammatory, antioxidant, antidiabetic and cardioprotective effects. We previously reported that RA effectively inhibits diabetic endothelial dysfunction by inhibiting inflammasome activation in endothelial cells. However, its effect on cholesterol efflux remains Citation: Nyandwi, J.-B.; Ko, Y.S.; unknown. Therefore, in this study, we aimed to assess the effect of RA on cholesterol efflux and its Jin, H.; Yun, S.P.; Park, S.W.; Kim, H.J.
    [Show full text]
  • ABC Transporter Genes and Risk of Type 2 Diabetes a Study of 40,000 Individuals from the General Population
    Cardiovascular and Metabolic Risk ORIGINAL ARTICLE ABC Transporter Genes and Risk of Type 2 Diabetes A study of 40,000 individuals from the general population 1,2 2,3,4,6 JESPER SCHOU, MSC BØRGE G. NORDESTGAARD, MD, DMSC secretion in mice (2). In humans, family 1,2,3,4 1,2,4 ANNE TYBJÆRG-HANSEN, MD, DMSC RUTH FRIKKE-SCHMIDT, MD, DMSC 5 studies and small case-control studies HOLGER J. MØLLER, MD, PHD have suggested that loss-of-function muta- tions in ABCA1 associate with decreased in- sulin secretion (8) or type 2 diabetes (9). OBJECTIVEd b b Alterations of pancreatic -cell cholesterol content may contribute to -cell Further, macrophages from diabetic mice dysfunction. Two important determinants of intracellular cholesterol content are the ATP- (10) and humans (11) display decreased binding cassette (ABC) transporters A1 (ABCA1) and -G1 (ABCG1). Whether genetic variation ABCG1 expression. Finally, we recently re- in ABCA1 and ABCG1 predicts risk of type 2 diabetes in the general population is unknown. ported that two functional variants, ABCA1 RESEARCH DESIGN AND METHODSdWe tested whether genetic variation in the N1800H and ABCG1 g.-376C.T, were as- promoter and coding regions of ABCA1 and ABCG1 predicted risk of type 2 diabetes in the sociated with, respectively, substantial re- general population. Twenty-seven variants, identified by previous resequencing of both genes, ductions in levels of HDL cholesterol or were genotyped in the Copenhagen City Heart Study (CCHS) (n = 10,185). Two loss-of-function reduced ABCG1 mRNA expression levels mutations (ABCA1 N1800H and ABCG1 g.-376C.T) (n = 322) and a common variant (ABCG1 .
    [Show full text]
  • Characterizing the Interaction of the ATP Binding Cassette Transporters (G Subfamily) with the Intracellular Protein Lipid Environment
    Characterizing the Interaction of the ATP Binding Cassette Transporters (G subfamily) with the Intracellular Protein Lipid Environment Sonia Gulati Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy under the Executive Committee of the Graduate School of Arts and Sciences Columbia University 2011 © 2011 Sonia Gulati All Rights Reserved Abstract Characterizing the Interaction of the ATP Binding Cassette Transporters (G subfamily) with the Intracellular Protein Lipid Environment Sonia Gulati Cholesterol is an essential molecule that mediates a myriad of critical cellular processes, such as signal transduction in eukaryotes, membrane fluidity, and steroidogenesis. As such it is not surprising that cholesterol homeostasis is tightly regulated, striking a precise balance between endogenous synthesis and regulated uptake/efflux to and from extracellular acceptors. In mammalian cells, sterol efflux is a key component of the homeostatic equation and is mediated by members of the ATP binding cassette (ABC) transporter superfamily. ATP-binding cassette (ABC) transporters represent a group of evolutionarily highly conserved cellular transmembrane proteins that mediate the ATP-dependent translocation of substrates across membranes. Members of this superfamily, ABCA1 and ABCG1, are key components of the reverse cholesterol transport pathway. ABCG1 acts in concert with ABCA1 to maximize the removal of excess cholesterol from cells by promoting cholesterol efflux onto mature and nascent HDL particles, respectively. To date, mammalian ABC transporters are exclusively associated with efflux of cholesterol. In Saccharomyces cerevisiae, we have demonstrated that the opposite (i.e inward) transport of sterol in yeast is also dependent on two ABC transporters (Aus1p and Pdr11p). This prompts the question what dictates directionality of sterol transport by ABC transporters.
    [Show full text]
  • Identification of Placental Nutrient Transporters Associated With
    Huang et al. BMC Genomics (2018) 19:173 https://doi.org/10.1186/s12864-018-4518-z RESEARCHARTICLE Open Access Identification of placental nutrient transporters associated with intrauterine growth restriction and pre-eclampsia Xiao Huang1,2, Pascale Anderle3,4, Lu Hostettler2, Marc U. Baumann1,5, Daniel V. Surbek1,5, Edgar C. Ontsouka1,2 and Christiane Albrecht1,2* Abstract Background: Gestational disorders such as intrauterine growth restriction (IUGR) and pre-eclampsia (PE) are main causes of poor perinatal outcomes worldwide. Both diseases are related with impaired materno-fetal nutrient transfer, but the crucial transport mechanisms underlying IUGR and PE are not fully elucidated. In this study, we aimed to identify membrane transporters highly associated with transplacental nutrient deficiencies in IUGR/PE. Results: In silico analyses on the identification of differentially expressed nutrient transporters were conducted using seven eligible microarray datasets (from Gene Expression Omnibus), encompassing control and IUGR/PE placental samples. Thereby 46 out of 434 genes were identified as potentially interesting targets. They are involved in the fetal provision with amino acids, carbohydrates, lipids, vitamins and microelements. Targets of interest were clustered into a substrate-specific interaction network by using Search Tool for the Retrieval of Interacting Genes. The subsequent wet-lab validation was performed using quantitative RT-PCR on placentas from clinically well- characterized IUGR/PE patients (IUGR, n =8;PE,n =5;PE+IUGR,n = 10) and controls (term, n = 13; preterm, n = 7), followed by 2D-hierarchical heatmap generation. Statistical evaluation using Kruskal-Wallis tests was then applied to detect significantly different expression patterns, while scatter plot analysis indicated which transporters were predominantly influenced by IUGR or PE, or equally affected by both diseases.
    [Show full text]