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Donovan MG, Rachubinski AL, Smith KP, Araya P, Waugh KA, Enriquez-Estrada B, Britton EC, Lyford HR, Granrath RE, Schade KA, Kinning KT, Paul Eduthan N, Sullivan KD, Galbraith MD, Espinosa JM. Multimodal analysis of dysregulated heme metabolism, hypoxic signaling, and stress erythropoiesis in Down syndrome. Cell Rep 2024; 43:114599. [PMID: 39120971 DOI: 10.1016/j.celrep.2024.114599] [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: 01/24/2024] [Revised: 06/25/2024] [Accepted: 07/23/2024] [Indexed: 08/11/2024] Open
Abstract
Down syndrome (DS), the genetic condition caused by trisomy 21 (T21), is characterized by delayed neurodevelopment, accelerated aging, and increased risk of many co-occurring conditions. Hypoxemia and dysregulated hematopoiesis have been documented in DS, but the underlying mechanisms and clinical consequences remain ill defined. We report an integrative multi-omic analysis of ∼400 research participants showing that people with DS display transcriptomic signatures indicative of elevated heme metabolism and increased hypoxic signaling across the lifespan, along with chronic overproduction of erythropoietin, elevated biomarkers of tissue-specific hypoxia, and hallmarks of stress erythropoiesis. Elevated heme metabolism, transcriptional signatures of hypoxia, and stress erythropoiesis are conserved in a mouse model of DS and associated with overexpression of select triplicated genes. These alterations are independent of the hyperactive interferon signaling characteristic of DS. These results reveal lifelong dysregulation of key oxygen-related processes that could contribute to the developmental and clinical hallmarks of DS.
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Affiliation(s)
- Micah G Donovan
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Angela L Rachubinski
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Department of Pediatrics, Section of Developmental Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Keith P Smith
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Paula Araya
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Katherine A Waugh
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Department of Cell Biology and Physiology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Belinda Enriquez-Estrada
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Eleanor C Britton
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Hannah R Lyford
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Ross E Granrath
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Kyndal A Schade
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Kohl T Kinning
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Neetha Paul Eduthan
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Kelly D Sullivan
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Department of Pediatrics, Section of Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Matthew D Galbraith
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
| | - Joaquin M Espinosa
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
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2
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Dean M, Moitra K, Allikmets R. The human ATP-binding cassette (ABC) transporter superfamily. Hum Mutat 2022; 43:1162-1182. [PMID: 35642569 PMCID: PMC9357071 DOI: 10.1002/humu.24418] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 05/26/2022] [Accepted: 05/27/2022] [Indexed: 11/12/2022]
Abstract
The ATP-binding cassette (ABC) transporter superfamily comprises membrane proteins that efflux various substrates across extra- and intracellular membranes. Mutations in ABC genes cause 21 human disorders or phenotypes with Mendelian inheritance, including cystic fibrosis, adrenoleukodystrophy, retinal degeneration, cholesterol, and bile transport defects. To provide tools to study the function of human ABC transporters we compiled data from multiple genomics databases. We analyzed ABC gene conservation within human populations and across vertebrates and surveyed phenotypes of ABC gene mutations in mice. Most mouse ABC gene disruption mutations have a phenotype that mimics human disease, indicating they are applicable models. Interestingly, several ABCA family genes, whose human function is unknown, have cholesterol level phenotypes in the mouse. Genome-wide association studies confirm and extend ABC traits and suggest several new functions to investigate. Whole-exome sequencing of tumors from diverse cancer types demonstrates that mutations in ABC genes are not common in cancer, but specific genes are overexpressed in select tumor types. Finally, an analysis of the frequency of loss-of-function mutations demonstrates that many human ABC genes are essential with a low level of variants, while others have a higher level of genetic diversity.
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Affiliation(s)
- Michael Dean
- Laboratory of Translational Genomics, National Cancer Institute, Gaithersburg, Maryland 21702
| | | | - Rando Allikmets
- Department of Ophthalmology, Columbia University, New York, New York, 10032
- Department of Pathology & Cell Biology, Columbia University, New York, New York, 10032
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3
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Kroll T, Prescher M, Smits SHJ, Schmitt L. Structure and Function of Hepatobiliary ATP Binding Cassette Transporters. Chem Rev 2020; 121:5240-5288. [PMID: 33201677 DOI: 10.1021/acs.chemrev.0c00659] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The liver is beyond any doubt the most important metabolic organ of the human body. This function requires an intensive crosstalk within liver cellular structures, but also with other organs. Membrane transport proteins are therefore of upmost importance as they represent the sensors and mediators that shuttle signals from outside to the inside of liver cells and/or vice versa. In this review, we summarize the known literature of liver transport proteins with a clear emphasis on functional and structural information on ATP binding cassette (ABC) transporters, which are expressed in the human liver. These primary active membrane transporters form one of the largest families of membrane proteins. In the liver, they play an essential role in for example bile formation or xenobiotic export. Our review provides a state of the art and comprehensive summary of the current knowledge of hepatobiliary ABC transporters. Clearly, our knowledge has improved with a breath-taking speed over the last few years and will expand further. Thus, this review will provide the status quo and will lay the foundation for new and exciting avenues in liver membrane transporter research.
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Affiliation(s)
- Tim Kroll
- Institute of Biochemistry, Heinrich Heine University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Martin Prescher
- Institute of Biochemistry, Heinrich Heine University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Sander H J Smits
- Institute of Biochemistry, Heinrich Heine University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany.,Center for Structural Studies, Heinrich Heine University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Lutz Schmitt
- Institute of Biochemistry, Heinrich Heine University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany
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Mao X, He Z, Zhou F, Huang Y, Zhu G. Prognostic significance and molecular mechanisms of adenosine triphosphate-binding cassette subfamily C members in gastric cancer. Medicine (Baltimore) 2019; 98:e18347. [PMID: 31852133 PMCID: PMC6922578 DOI: 10.1097/md.0000000000018347] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Gastric cancer (GC) is one of the major leading causes of tumor-related deaths worldwide. Adenosine triphosphate-binding cassette subfamily C (ABCC) consists of 13 members, ABCC1 to 13, which were examined for their associations with GC.The online Kaplan-Meier Plotter database was used to determine the prognostic significance of ABCC subfamily members in GC. Stratified analyses were performed using gender, disease stage, degree of tumor differentiation, expression of human epidermal growth factor receptor 2 (HER2), and Lauren classification. Molecular mechanisms were examined using the database for annotation, visualization, and integrated discovery database.ABCC1, ABCC3, ABCC7, ABCC8, ABCC9, and ABCC10 expression showed prognostic significance in the whole population and in male and female subpopulations (all P ≤ .05). Furthermore, high expression of most ABCC family members always suggested a poor prognosis, except for ABCC7 (P > .05). Stratified analyses revealed that ABCC1, ABCC3, ABCC7, ABCC8, ABCC9, and ABCC10 expression showed prognostic significance for the whole population, as well as male and female populations. ABCC2 and ABCC9 were significantly correlated with all disease stages, while ABCC2 and ABCC6 were significantly correlated with all Lauren classifications. Expression of ABCC1, ABCC3, ABCC5, ABCC7, ABCC8, ABCC9, and ABCC10 was significantly correlated with either negative or positive of HER2 status (all P ≤ .05). Enrichment analysis indicated that these genes were involved in ATPase activity, transmembrane transport, or were ABC transporters (all P ≤ .05).ABCC1, ABCC3, ABCC7, ABCC8, ABCC9, and ABCC10 may be potential prognosis biomarkers for GC, acting as ABC transporters and via ATPase activity.
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Affiliation(s)
- Xianshuang Mao
- Department of Hepatobiliary Gastrointestinal Surgery, The People's Hospital of Hezhou City, Hezhou
| | - Zhenhua He
- Department of Hepatobiliary Gastrointestinal Surgery, The People's Hospital of Hezhou City, Hezhou
| | - Fengsheng Zhou
- Department of Hepatobiliary Gastrointestinal Surgery, The People's Hospital of Hezhou City, Hezhou
| | - Yongchu Huang
- Department of Hepatobiliary Gastrointestinal Surgery, The People's Hospital of Hezhou City, Hezhou
| | - Guangzhi Zhu
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Province, China
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Ren J, Chung-Davidson YW, Yeh CY, Scott C, Brown T, Li W. Genome-wide analysis of the ATP-binding cassette (ABC) transporter gene family in sea lamprey and Japanese lamprey. BMC Genomics 2015; 16:436. [PMID: 26047617 PMCID: PMC4458048 DOI: 10.1186/s12864-015-1677-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 06/01/2015] [Indexed: 11/26/2022] Open
Abstract
Background Lampreys are extant representatives of the jawless vertebrate lineage that diverged from jawed vertebrates around 500 million years ago. Lamprey genomes contain information crucial for understanding the evolution of gene families in vertebrates. The ATP-binding cassette (ABC) gene family is found from prokaryotes to eukaryotes. The recent availability of two lamprey draft genomes from sea lamprey Petromyzon marinus and Japanese lamprey Lethenteron japonicum presents an opportunity to infer early evolutionary events of ABC genes in vertebrates. Results We conducted a genome-wide survey of the ABC gene family in two lamprey draft genomes. A total of 37 ABC transporters were identified and classified into seven subfamilies; namely seven ABCA genes, 10 ABCB genes, 10 ABCC genes, three ABCD genes, one ABCE gene, three ABCF genes, and three ABCG genes. The ABCA subfamily has expanded from three genes in sea squirts, seven and nine in lampreys and zebrafish, to 13 and 16 in human and mouse. Conversely, the multiple copies of ABCB1-, ABCG1-, and ABCG2-like genes found in sea squirts have contracted in the other species examined. ABCB2 and ABCB3 seem to be new additions in gnathostomes (not in sea squirts or lampreys), which coincides with the emergence of the gnathostome-specific adaptive immune system. All the genes in the ABCD, ABCE and ABCF subfamilies were conserved and had undergone limited duplication and loss events. In the sea lamprey transcriptomes, the ABCE and ABCF gene subfamilies were ubiquitously and highly expressed in all tissues while the members in other gene subfamilies were differentially expressed. Conclusions Thirteen more lamprey ABC transporter genes were identified in this study compared with a previous study. By concatenating the same gene sequences from the two lampreys, more full length sequences were obtained, which significantly improved both the assignment of gene names and the phylogenetic trees compared with a previous analysis using partial sequences. The ABC gene subfamilies in chordates have undergone obvious expansion or contraction. The ABCA subfamily showed the highest gene expansion rate during chordate evolution. The evolution of ABC transporters in lampreys requires further evaluation because the present results are based on a draft genome. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1677-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jianfeng Ren
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, College of Fisheries and Life Sciences, Shanghai Ocean University, Shanghai, 201306, China.
| | - Yu-Wen Chung-Davidson
- Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI, 48824, USA.
| | - Chu-Yin Yeh
- Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI, 48824, USA.
| | - Camille Scott
- Department of Computer Science and Engineering, Michigan State University, East Lansing, MI, 48824, USA.
| | - Titus Brown
- Department of Computer Science and Engineering, Michigan State University, East Lansing, MI, 48824, USA. .,Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, 48824, USA.
| | - Weiming Li
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, College of Fisheries and Life Sciences, Shanghai Ocean University, Shanghai, 201306, China. .,Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI, 48824, USA.
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6
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Luckenbach T, Fischer S, Sturm A. Current advances on ABC drug transporters in fish. Comp Biochem Physiol C Toxicol Pharmacol 2014; 165:28-52. [PMID: 24858718 DOI: 10.1016/j.cbpc.2014.05.002] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 05/13/2014] [Accepted: 05/14/2014] [Indexed: 01/14/2023]
Abstract
Most members of the large ATP-binding cassette (ABC) gene family are transporters involved in substrate translocation across biological membranes. In eukaryotes, ABC proteins functioning as drug transporters are located in the plasma membrane and mediate the cellular efflux of a wide range of organic chemicals, with some transporters also transporting certain metals. As the enhanced expression of ABC drug transporters can confer multidrug resistance (MDR) to cancers and multixenobiotic resistance (MXR) to organisms from polluted habitats, these ABC family members are also referred to as MDR or MXR proteins. In mammals, ABC drug transporters show predominant expression in tissues involved in excretion or constituting internal or external body boundaries, where they facilitate the excretion of chemicals and their metabolites, and limit chemical uptake and penetration into "sanctuary" sites of the body. Available knowledge about ABC proteins is still limited in teleost fish, a large vertebrate group of high ecological and economic importance. Using transport activity measurements and immunochemical approaches, early studies demonstrated similarities in the tissue distribution of ABC drug transporters between teleosts and mammals, suggesting conserved roles of the transporters in the biochemical defence against toxicants. Recently, the availability of teleost genome assemblies has stimulated studies of the ABC family in this taxon. This review summarises the current knowledge regarding the genetics, functional properties, physiological function, and ecotoxicological relevance of teleostean ABC transporters. The available literature is reviewed with emphasis on recent studies addressing the tissue distribution, substrate spectrum, regulation, physiological function and phylogenetic origin of teleostean ABC transporters.
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Affiliation(s)
- Till Luckenbach
- Department of Bioanalytical Ecotoxicology, UFZ-Helmholtz Centre for Environmental Research, 04318 Leipzig, Germany
| | - Stephan Fischer
- Department of Environmental Toxicology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland; Department of Environmental Systems Sciences, ETH Zürich, Institute of Biogeochemistry and Pollutant Dynamics, 8092 Zürich, Switzerland
| | - Armin Sturm
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling FK9 4LA, Scotland, UK.
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7
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Abstract
Multidrug resistance presents one of the most important causes of cancer treatment failure. Numerous in vitro and in vivo data have made it clear that multidrug resistance is frequently caused by enhanced expression of ATP-binding cassette (ABC) transporters. ABC transporters are membrane-bound proteins involved in cellular defense mechanisms, namely, in outward transport of xenobiotics and physiological substrates. Their function thus prevents toxicity as carcinogenesis on one hand but may contribute to the resistance of tumor cells to a number of drugs including chemotherapeutics on the other. Within 48 members of the human ABC superfamily there are several multidrug resistance-associated transporters. Due to the well documented susceptibility of numerous drugs to efflux via ABC transporters it is highly desirable to assess the status of ABC transporters for individualization of treatment by their substrates. The multidrug resistance associated protein 1 (MRP1) encoded by ABCC1 gene is one of the most studied ABC transporters. Despite the fact that its structure and functions have already been explored in detail, there are significant gaps in knowledge which preclude clinical applications. Tissue-specific patterns of expression and broad genetic variability make ABCC1/MRP1 an optimal candidate for use as a marker or member of multi-marker panel for prediction of chemotherapy resistance. The purpose of this review was to summarize investigations about associations of gene and protein expression and genetic variability with prognosis and therapy outcome of major cancers. Major advances in the knowledge have been identified and future research directions are highlighted.
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Affiliation(s)
- Tereza Kunická
- Department of Toxicogenomics, National Institute of Public Health , Prague , Czech Republic
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8
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Zhang Y, Jia Z, Yin S, Shan A, Gao R, Qu Z, Liu M, Nie S. Toxic effects of maternal zearalenone exposure on uterine capacity and fetal development in gestation rats. Reprod Sci 2013; 21:743-53. [PMID: 24357638 DOI: 10.1177/1933719113512533] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The objectives of this study were to determine the effects of high-dose and early gestational exposure to zearalenone (ZEN) in female Sprague-Dawley (SD) rats, to correlate the maternal uterus with the fetus, and to explore the development and malformation of fetuses. Pregnant female SD rats were fed diets containing 0.3, 48.5, 97.6, or 146.0 mg/kg ZEN on gestational days (GDs) 0 through 7. All the females survived until GD 20, at which point a cesarean section was performed to harvest the organs, blood, and fetuses. The results indicated that exposure to ZEN during early gestation can impact the maternal reproductive capability. Delayed fetal development was directly linked to maternal toxicity. The toxic effects of ZEN caused early deaths more frequently than late deaths, and the deleterious effects lasted through the end of pregnancy.
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Affiliation(s)
- Yuanyuan Zhang
- 1Institute of Animal Nutrition, Northeast Agricultural University, Harbin, People's Republic of China
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9
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Luciano M, Evans DM, Hansell NK, Medland SE, Montgomery GW, Martin NG, Wright MJ, Bates TC. A genome-wide association study for reading and language abilities in two population cohorts. GENES BRAIN AND BEHAVIOR 2013; 12:645-52. [PMID: 23738518 PMCID: PMC3908370 DOI: 10.1111/gbb.12053] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Revised: 03/04/2013] [Accepted: 05/24/2013] [Indexed: 01/21/2023]
Abstract
Candidate genes have been identified for both reading and language, but most of the heritable variance in these traits remains unexplained. Here, we report a genome-wide association meta-analysis of two large cohorts: population samples of Australian twins and siblings aged 12–25 years (n = 1177 from 538 families), and a younger cohort of children of the UK Avon Longitudinal Study of Parents and their Children (aged 8 and 9 years; maximum n = 5472). Suggestive association was indicated for reading measures and non-word repetition (NWR), with the greatest support found for single nucleotide polymorphisms (SNPs) in the pseudogene, ABCC13 (P = 7.34 × 10−8), and the gene, DAZAP1 (P = 1.32 × 10−6). Gene-based analyses showed significant association (P < 2.8 × 10−6) for reading and spelling with genes CD2L1, CDC2L2 and RCAN3 in two loci on chromosome 1. Some support was found for the same SNPs having effects on both reading skill and NWR, which is compatible with behavior genetic evidence for influences of reading acquisition on phonological-task performance. The results implicate novel candidates for study in additional cohorts for reading and language abilities.
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Affiliation(s)
- M Luciano
- Centre for Cognitive Aging and Cognitive Epidemiology, Department of Psychology, University of Edinburgh, Edinburgh, UK.
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10
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Sodani K, Patel A, Kathawala RJ, Chen ZS. Multidrug resistance associated proteins in multidrug resistance. CHINESE JOURNAL OF CANCER 2011; 31:58-72. [PMID: 22098952 PMCID: PMC3777468 DOI: 10.5732/cjc.011.10329] [Citation(s) in RCA: 185] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Multidrug resistance proteins (MRPs) are members of the C family of a group of proteins named ATP-binding cassette (ABC) transporters. These ABC transporters together form the largest branch of proteins within the human body. The MRP family comprises of 13 members, of which MRP1 to MRP9 are the major transporters indicated to cause multidrug resistance in tumor cells by extruding anticancer drugs out of the cell. They are mainly lipophilic anionic transporters and are reported to transport free or conjugates of glutathione (GSH), glucuronate, or sulphate. In addition, MRP1 to MRP3 can transport neutral organic drugs in free form in the presence of free GSH. Collectively, MRPs can transport drugs that differ structurally and mechanistically, including natural anticancer drugs, nucleoside analogs, antimetabolites, and tyrosine kinase inhibitors. Many of these MRPs transport physiologically important anions such as leukotriene C4, bilirubin glucuronide, and cyclic nucleotides. This review focuses mainly on the physiological functions, cellular resistance characteristics, and probable in vivo role of MRP1 to MRP9.
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Affiliation(s)
- Kamlesh Sodani
- Department of Pharmaceutical Sciences, St. John's University, Queens, NY 11439, USA
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11
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Hesse M, Willscher E, Schmiedel BJ, Posch S, Golbik RP, Staege MS. Sequence and expression of the chicken membrane-associated phospholipases A1 alpha (LIPH) and beta (LIPI). Mol Biol Rep 2011; 39:761-9. [PMID: 21559832 DOI: 10.1007/s11033-011-0796-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2010] [Accepted: 04/29/2011] [Indexed: 12/18/2022]
Abstract
Cancer/testis antigens (CTA) are a heterogeneous group of antigens that are expressed preferentially in tumor cells and testis. Based on this definition the human membrane-associated phospholipase A1 beta (lipase family member I, LIPI) has been identified as CTA. The high homology of LIPI and the membrane-associated phospholipase A1 alpha (lipase family member H, LIPH) suggests that both genes are derived from a common ancestor by gene duplication. In contrast to human LIPI, human LIPH is expressed in several tissues. LIPI sequences have only been identified in mammals. Here, we describe the identification of LIPI in non-mammalian vertebrates. Based on the conserved genomic organization of LIPI and LIPH we identified sequences for both lipases in birds and fishes. In all vertebrates the LIPI locus is neighbored by a member of the RNA binding motif (RBM) family, RBM11. By sequencing of reverse transcriptase-polymerase chain reaction products we determined the sequences of LIPI and LIPH messenger RNA from broilers. We found that the sequence homology between LIPI and LIPH is much higher in non-mammalian species than in mammals. In addition, we found broad expression of LIPI in broilers, resembling the expression profile of LIPH. Our data suggest that LIPI is a CTA only in mammalian species and that the unique sequence features of the mammalian LIPI/RBM11 locus have evolved together with the CTA-like expression pattern of LIPI.
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Affiliation(s)
- Manuela Hesse
- Department of Pediatrics, Children's Cancer Research Centre, Martin-Luther-University Halle-Wittenberg, Ernst Grube Str. 40, 06097, Halle, Germany
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12
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Moitra K, Dean M. Evolution of ABC transporters by gene duplication and their role in human disease. Biol Chem 2011; 392:29-37. [DOI: 10.1515/bc.2011.006] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The ATP-binding cassette (ABC) transporter genes represent the largest family of transporters and these genes are abundant in the genome of all vertebrates. Through analysis of the genome sequence databases we have characterized the full complement of ABC genes from several mammals and other vertebrates. Multiple gene duplication and deletion events were identified in ABC genes in different lineages indicating that the process of gene evolution is still ongoing. Gene duplication resulting in either gene birth or gene death plays a major role in the evolution of the vertebrate ABC genes. The understanding of this mechanism is important in the context of human health because these ABC genes are associated with human disease, involving nearly all organ systems of the body. In addition, ABC genes play an important role in the development of drug resistance in cancer cells. Future genetic, functional, and evolutionary studies of ABC transporters will provide important insight into human and animal biology.
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13
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Gu X, Manautou JE. Regulation of hepatic ABCC transporters by xenobiotics and in disease states. Drug Metab Rev 2010; 42:482-538. [PMID: 20233023 DOI: 10.3109/03602531003654915] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The subfamily of ABCC transporters consists of 13 members in mammals, including the multidrug resistance-associated proteins (MRPs), sulfonylurea receptors (SURs), and the cystic fibrosis transmembrane conductance regulator (CFTR). These proteins play roles in chemical detoxification, disposition, and normal cell physiology. ABCC transporters are expressed differentially in the liver and are regulated at the transcription and translation level. Their expression and function are also controlled by post-translational modification and membrane-trafficking events. These processes are tightly regulated. Information about alterations in the expression of hepatobiliary ABCC transporters could provide important insights into the pathogenesis of diseases and disposition of xenobiotics. In this review, we describe the regulation of hepatic ABCC transporters in humans and rodents by a variety of xenobiotics, under disease states and in genetically modified animal models deficient in transcription factors, transporters, and cell-signaling molecules.
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Affiliation(s)
- Xinsheng Gu
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, 06269, USA
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14
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Klaassen CD, Aleksunes LM. Xenobiotic, bile acid, and cholesterol transporters: function and regulation. Pharmacol Rev 2010; 62:1-96. [PMID: 20103563 PMCID: PMC2835398 DOI: 10.1124/pr.109.002014] [Citation(s) in RCA: 561] [Impact Index Per Article: 40.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Transporters influence the disposition of chemicals within the body by participating in absorption, distribution, and elimination. Transporters of the solute carrier family (SLC) comprise a variety of proteins, including organic cation transporters (OCT) 1 to 3, organic cation/carnitine transporters (OCTN) 1 to 3, organic anion transporters (OAT) 1 to 7, various organic anion transporting polypeptide isoforms, sodium taurocholate cotransporting polypeptide, apical sodium-dependent bile acid transporter, peptide transporters (PEPT) 1 and 2, concentrative nucleoside transporters (CNT) 1 to 3, equilibrative nucleoside transporter (ENT) 1 to 3, and multidrug and toxin extrusion transporters (MATE) 1 and 2, which mediate the uptake (except MATEs) of organic anions and cations as well as peptides and nucleosides. Efflux transporters of the ATP-binding cassette superfamily, such as ATP-binding cassette transporter A1 (ABCA1), multidrug resistance proteins (MDR) 1 and 2, bile salt export pump, multidrug resistance-associated proteins (MRP) 1 to 9, breast cancer resistance protein, and ATP-binding cassette subfamily G members 5 and 8, are responsible for the unidirectional export of endogenous and exogenous substances. Other efflux transporters [ATPase copper-transporting beta polypeptide (ATP7B) and ATPase class I type 8B member 1 (ATP8B1) as well as organic solute transporters (OST) alpha and beta] also play major roles in the transport of some endogenous chemicals across biological membranes. This review article provides a comprehensive overview of these transporters (both rodent and human) with regard to tissue distribution, subcellular localization, and substrate preferences. Because uptake and efflux transporters are expressed in multiple cell types, the roles of transporters in a variety of tissues, including the liver, kidneys, intestine, brain, heart, placenta, mammary glands, immune cells, and testes are discussed. Attention is also placed upon a variety of regulatory factors that influence transporter expression and function, including transcriptional activation and post-translational modifications as well as subcellular trafficking. Sex differences, ontogeny, and pharmacological and toxicological regulation of transporters are also addressed. Transporters are important transmembrane proteins that mediate the cellular entry and exit of a wide range of substrates throughout the body and thereby play important roles in human physiology, pharmacology, pathology, and toxicology.
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Affiliation(s)
- Curtis D Klaassen
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160-7417, USA.
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Nies AT, Schwab M, Keppler D. Interplay of conjugating enzymes with OATP uptake transporters and ABCC/MRP efflux pumps in the elimination of drugs. Expert Opin Drug Metab Toxicol 2008; 4:545-68. [PMID: 18484914 DOI: 10.1517/17425255.4.5.545] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Biliary excretion is a major elimination route of many drugs and their metabolites. Hepatobiliary elimination is a vectorial process involving uptake transporters in the basolateral hepatocyte membrane, possibly Phase I and Phase II metabolizing enzymes, and ATP-dependent efflux pumps in the apical hepatocyte membrane. OBJECTIVES Because many drugs and their metabolites are anions, this review focuses on transporters involved in their hepatocellular uptake (members of the organic anion transporting polypeptide (OATP) family) and biliary elimination (apical conjugate efflux pump ABCC2/MRP2). METHODS The molecular and functional characteristics of the human OATP and ABCC/MRP transporters are presented, including a detailed overview of endogenous and drug substrates. Examples illustrate the interplay of transporters with Phase II conjugating enzymes. Model systems to study the vectorial transport of organic anions are also discussed. RESULTS/CONCLUSIONS OATP uptake transporters, conjugating enzymes, and ABCC2/MRP2 work in concert to enable the hepatobiliary elimination of anionic drugs and their metabolites. It is increasingly important to understand how genetic variants of these transporters and enzymes influence the interindividual variability of drug elimination.
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Affiliation(s)
- Anne T Nies
- Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart and University of Tübingen, Auerbachstrasse 112, 70376 Stuttgart, Germany.
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16
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Meijerman I, Beijnen JH, Schellens JH. Combined action and regulation of phase II enzymes and multidrug resistance proteins in multidrug resistance in cancer. Cancer Treat Rev 2008; 34:505-20. [DOI: 10.1016/j.ctrv.2008.03.002] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2007] [Revised: 02/11/2008] [Accepted: 03/01/2008] [Indexed: 01/16/2023]
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Toyoda Y, Hagiya Y, Adachi T, Hoshijima K, Kuo MT, Ishikawa T. MRP class of human ATP binding cassette (ABC) transporters: historical background and new research directions. Xenobiotica 2008; 38:833-62. [DOI: 10.1080/00498250701883514] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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18
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Ono N, Van der Heijden I, Scheffer G, Van de Wetering K, Van Deemter E, De Haas M, Boerke A, Gadella B, De Rooij D, Neefjes J, Groothuis T, Oomen L, Brocks L, Ishikawa T, Borst P. Multidrug resistance-associated protein 9 (ABCC12) is present in mouse and boar sperm. Biochem J 2007; 406:31-40. [PMID: 17472575 PMCID: PMC1948986 DOI: 10.1042/bj20070292] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The human and murine genes for MRP9 (multidrug resistance-associated protein 9; ABCC12) yield many alternatively spliced RNAs. Using a panel of monoclonal antibodies, we detected full-length Mrp9 only in testicular germ cells and mouse sperm; we obtained no evidence for the existence of the truncated 100 kDa MRP9 protein reported previously. In contrast with other MRPs, neither murine Mrp9 nor the human MRP9 produced in MRP9-transfected HEK-293 cells (human embryonic kidney cells) appears to contain N-linked carbohydrates. In mouse and boar sperm, Mrp9 localizes to the midpiece, a structure containing all sperm mitochondria. However, immunolocalization microscopy and cell fractionation studies with transfected HEK-293 cells and mouse testis show that MRP9/Mrp9 does not localize to mitochondria. In HEK-293 cells, it is predominantly localized in the endoplasmic reticulum. We have been unable to demonstrate transport by MRP9 of substrates transported by other MRPs, such as drug conjugates and other organic anions.
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Affiliation(s)
- Nobuhito Ono
- *Division of Molecular Biology and Center of Biomedical Genetics, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Ingrid Van der Heijden
- *Division of Molecular Biology and Center of Biomedical Genetics, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - George L. Scheffer
- †Department of Pathology, Free University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Koen Van de Wetering
- *Division of Molecular Biology and Center of Biomedical Genetics, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Elizabeth Van Deemter
- *Division of Molecular Biology and Center of Biomedical Genetics, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Marcel De Haas
- *Division of Molecular Biology and Center of Biomedical Genetics, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Arjan Boerke
- ‡Department of Biochemistry and Cell Biology, Utrecht University, Yalelaan 2, 3508 TD Utrecht, The Netherlands
- §Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 2, 3508 TD Utrecht, The Netherlands
| | - Bart M. Gadella
- ‡Department of Biochemistry and Cell Biology, Utrecht University, Yalelaan 2, 3508 TD Utrecht, The Netherlands
- §Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 2, 3508 TD Utrecht, The Netherlands
| | - Dirk G. De Rooij
- ∥Department of Endocrinology, Faculty of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
- ¶Department of Cell Biology, UMCU (University Medical Centre Utrecht), Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Jacques J. Neefjes
- **Division of Tumor Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Tom A. M. Groothuis
- **Division of Tumor Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Lauran Oomen
- **Division of Tumor Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Lenny Brocks
- **Division of Tumor Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Toshihisa Ishikawa
- ††Department of Biomolecular Engineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta, Midoziku, Yokohama 226-8501, Japan
| | - Piet Borst
- *Division of Molecular Biology and Center of Biomedical Genetics, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
- To whom correspondence should be addressed (email )
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Deeley RG, Westlake C, Cole SPC. Transmembrane transport of endo- and xenobiotics by mammalian ATP-binding cassette multidrug resistance proteins. Physiol Rev 2006; 86:849-99. [PMID: 16816140 DOI: 10.1152/physrev.00035.2005] [Citation(s) in RCA: 533] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Multidrug Resistance Proteins (MRPs), together with the cystic fibrosis conductance regulator (CFTR/ABCC7) and the sulfonylurea receptors (SUR1/ABCC8 and SUR2/ABCC9) comprise the 13 members of the human "C" branch of the ATP binding cassette (ABC) superfamily. All C branch proteins share conserved structural features in their nucleotide binding domains (NBDs) that distinguish them from other ABC proteins. The MRPs can be further divided into two subfamilies "long" (MRP1, -2, -3, -6, and -7) and "short" (MRP4, -5, -8, -9, and -10). The short MRPs have a typical ABC transporter structure with two polytropic membrane spanning domains (MSDs) and two NBDs, while the long MRPs have an additional NH2-terminal MSD. In vitro, the MRPs can collectively confer resistance to natural product drugs and their conjugated metabolites, platinum compounds, folate antimetabolites, nucleoside and nucleotide analogs, arsenical and antimonial oxyanions, peptide-based agents, and, under certain circumstances, alkylating agents. The MRPs are also primary active transporters of other structurally diverse compounds, including glutathione, glucuronide, and sulfate conjugates of a large number of xeno- and endobiotics. In vivo, several MRPs are major contributors to the distribution and elimination of a wide range of both anticancer and non-anticancer drugs and metabolites. In this review, we describe what is known of the structure of the MRPs and the mechanisms by which they recognize and transport their diverse substrates. We also summarize knowledge of their possible physiological functions and evidence that they may be involved in the clinical drug resistance of various forms of cancer.
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Affiliation(s)
- Roger G Deeley
- Division of Cancer Biology and Genetics, Cancer Research Institute and Department of Biochemistry, Queen's University Kingdom, Ontario, Canada.
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20
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Kruh GD, Guo Y, Hopper-Borge E, Belinsky MG, Chen ZS. ABCC10, ABCC11, and ABCC12. Pflugers Arch 2006; 453:675-84. [PMID: 16868766 DOI: 10.1007/s00424-006-0114-1] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2006] [Accepted: 06/06/2006] [Indexed: 01/23/2023]
Abstract
Multidrug resistance protein (MRP)7, MRP8, and MRP9 (gene symbols ABCC10, ABCC11, and ABCC12) are recently identified members of the MRP family that are at relatively early stages of investigation. Of these proteins, a physiological function has only been established for MRP8, for which a single nucleotide polymorphism determines wet vs dry earwax type. MRP7 and MRP8 are lipophilic anion pumps that are able to confer resistance to chemotherapeutic agents. MRP7 is competent in the transport of the glucuronide E(2)17betaG, and its resistance profile, which includes several natural product anticancer agents, is distinguished by the taxane docetaxel. MRP8 is able to transport a diverse range of lipophilic anions, including cyclic nucleotides, E(2)17betaG, steroid sulfates such as dehydroepiandrosterone (DHEAS) and E(1)S, glutathione conjugates such as leukotriene C4 and dinitrophenyl-S-glutathione, and monoanionic bile acids. However, the constituent of earwax that is susceptible to transport by MRP8 has not been identified. MRP8 has complex interactions with its substrates, as indicated by the nonreciprocal ability of DHEAS to stimulate E(2)17betaG transport. Similar to the case for other MRPs that possess only two membrane spanning domains (MRP4 and MRP5), MRP8 is a cyclic nucleotide efflux pump that is able to confer resistance to nucleoside-based agents, such as PMEA and 5FU. The functional characteristics of MRP9 are currently unknown.
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Affiliation(s)
- Gary D Kruh
- Medical Science Division, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
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21
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Annilo T, Chen ZQ, Shulenin S, Costantino J, Thomas L, Lou H, Stefanov S, Dean M. Evolution of the vertebrate ABC gene family: analysis of gene birth and death. Genomics 2006; 88:1-11. [PMID: 16631343 DOI: 10.1016/j.ygeno.2006.03.001] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2005] [Revised: 02/28/2006] [Accepted: 03/02/2006] [Indexed: 10/24/2022]
Abstract
Vertebrate evolution has been largely driven by the duplication of genes that allow for the acquisition of new functions. The ATP-binding cassette (ABC) proteins constitute a large and functionally diverse family of membrane transporters. The members of this multigene family are found in all cellular organisms, most often engaged in the translocation of a wide variety of substrates across lipid membranes. Because of the diverse function of these genes, their large size, and the large number of orthologs, ABC genes represent an excellent tool to study gene family evolution. We have identified ABC proteins from the sea squirt (Ciona intestinalis), zebrafish (Danio rerio), and chicken (Gallus gallus) and, using phylogenetic analysis, identified those genes with a one-to-one orthologous relationship to human ABC proteins. All ABC protein subfamilies found in Ciona and zebrafish correspond to the human subfamilies, with the exception of a single ABCH subfamily gene found only in zebrafish. Multiple gene duplication and deletion events were identified in different lineages, indicating an ongoing process of gene evolution. As many ABC genes are involved in human genetic diseases, and important drug transport phenotypes, the understanding of ABC gene evolution is important to the development of animal models and functional studies.
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Affiliation(s)
- Tarmo Annilo
- Laboratory of Genomic Diversity, Building 560, Room 21-18, NCI-Frederick, Frederick, MD 21702, USA
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Abstract
Until around 1990, most multigene families were thought to be subject to concerted evolution, in which all member genes of a family evolve as a unit in concert. However, phylogenetic analysis of MHC and other immune system genes showed a quite different evolutionary pattern, and a new model called birth-and-death evolution was proposed. In this model, new genes are created by gene duplication and some duplicate genes stay in the genome for a long time, whereas others are inactivated or deleted from the genome. Later investigations have shown that most non-rRNA genes including highly conserved histone or ubiquitin genes are subject to this type of evolution. However, the controversy over the two models is still continuing because the distinction between the two models becomes difficult when sequence differences are small. Unlike concerted evolution, the model of birth-and-death evolution can give some insights into the origins of new genetic systems or new phenotypic characters.
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Affiliation(s)
- Masatoshi Nei
- Institute of Molecular Evolutionary Genetics and1 Department of Biology, Pennsylvania State University, University Park, Pennsylvania 16802;
| | - Alejandro P. Rooney
- U.S. Department of Agriculture, Agricultural Research Service, National Center for Agricultural Utilization Research, Peoria, Illinois 61604;
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23
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Dean M, Annilo T. Evolution of the ATP-binding cassette (ABC) transporter superfamily in vertebrates. Annu Rev Genomics Hum Genet 2005; 6:123-42. [PMID: 16124856 DOI: 10.1146/annurev.genom.6.080604.162122] [Citation(s) in RCA: 449] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The ATP-binding cassette (ABC) superfamily of genes encode membrane proteins that transport a diverse set of substrates across membranes. Mutations in ABC transporters cause or contribute to many different Mendelian and complex disorders including adrenoleukodystrophy, cystic fibrosis, retinal degeneration, hypercholesterolemia, and cholestasis. The genes play important roles in protecting organisms from xenobiotics and transport compounds across the intestine, blood-brain barrier, and the placenta. There are 48 ABC genes in the human genome divided into seven subfamilies based on amino acid sequence similarities and phylogeny. These seven subfamilies are represented in all eukaryotic genomes and are therefore of ancient origin. Sequencing the genomes of numerous vertebrate organisms has allowed the complement of ABC transporters to be characterized and the evolution of the genes to be assessed. Most ABC transporters are conserved in all vertebrates, but there are also several examples of recent duplication and gene loss. For genes with a conserved ortholog, animal models have been identified or developed that can be used to probe the function and regulation of selected genes. Genes that are restricted to a specific group of animals may represent specialized functions that could provide insight into unique biological properties of that organism. Further characterization of all ABC transporters from the human genome and from model organisms will lead to additional insights into normal physiology and human disease.
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Affiliation(s)
- Michael Dean
- Human Genetics Section, Laboratory of Genomic Diversity, National Cancer Institute, Frederick, Maryland 21702, USA.
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Klement JF, Matsuzaki Y, Jiang QJ, Terlizzi J, Choi HY, Fujimoto N, Li K, Pulkkinen L, Birk DE, Sundberg JP, Uitto J. Targeted ablation of the abcc6 gene results in ectopic mineralization of connective tissues. Mol Cell Biol 2005; 25:8299-310. [PMID: 16135817 PMCID: PMC1234326 DOI: 10.1128/mcb.25.18.8299-8310.2005] [Citation(s) in RCA: 160] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2005] [Revised: 06/01/2005] [Accepted: 06/17/2005] [Indexed: 12/19/2022] Open
Abstract
Pseudoxanthoma elasticum (PXE), characterized by connective tissue mineralization of the skin, eyes, and cardiovascular system, is caused by mutations in the ABCC6 gene. ABCC6 encodes multidrug resistance-associated protein 6 (MRP6), which is expressed primarily in the liver and kidneys. Mechanisms producing ectopic mineralization as a result of these mutations remain unclear. To elucidate this complex disease, a transgenic mouse was generated by targeted ablation of the mouse Abcc6 gene. Abcc6 null mice were negative for Mrp6 expression in the liver, and complete necropsies revealed profound mineralization of several tissues, including skin, arterial blood vessels, and retina, while heterozygous animals were indistinguishable from the wild-type mice. Particularly striking was the mineralization of vibrissae, as confirmed by von Kossa and alizarin red stains. Electron microscopy revealed mineralization affecting both elastic structures and collagen fibers. Mineralization of vibrissae was noted as early as 5 weeks of age and was progressive with age in Abcc6(-/-) mice but was not observed in Abcc6(+/-) or Abcc6(+/+) mice up to 2 years of age. A total body computerized tomography scan of Abcc6(-/-) mice revealed mineralization in skin and subcutaneous tissue as well as in the kidneys. These data demonstrate aberrant mineralization of soft tissues in PXE-affected organs, and, consequently, these mice recapitulate features of this complex disease.
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Affiliation(s)
- John F Klement
- Department of Dermatology, Jefferson Medical College, 233 S. 10th Street, Suite 322 BLSB, Philadelphia, PA 19107, USA.
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