MBL, P2X7, and SLC11A1 gene polymorphisms in patients with oropharyngeal tularemia.

Science.gov (United States)

Somuk, Battal Tahsin; Koc, Sema; Ates, Omer; Göktas, Göksel; Soyalic, Harun; Uysal, Ismail Onder; Gurbuzler, Levent; Sapmaz, Emrah; Sezer, Saime; Eyibilen, Ahmet

2016-11-01

A significant association was found of oropharyngeal tularemia with SLC11A1 allele polymorphism (INT4 G/C) and MBL2 C + 4T (P/Q). These results indicate C allele and Q allele might be a risk factor for the development of oropharyngeal tularemia. This study aimed to investigate the relationship of SLC11A1, MBL, and P2X 7 gene polymorphism with oropharyngeal tularemia. The study included totally 120 patients who were diagnosed with oropharyngeal tularemia. Frequencies of polymorphisms in the following genes were analyzed both in the patient and control groups in the study: SLC11A1 (5'(GT) n Allele 2/3, Int4 G/C, 3' UTR, D543N G/A), MBL (MBL2 C + 4T (P/Q), and P2X 7 (-762 C/T and 1513 A/C). Among all polymorphisms that were investigated in this study, SLC11A1 gene showed a significance in the distriburtion of polymorphism allelle frequency at the INT4 region. Frequency of C allele was 54 (28%) in patients with oropharyngeal tularemia, and 31 (13%) in the control group (p = 0.006 and OR = 1.96 (1.21-3.20)). An association was detected between MBL2 C + 4T (P/Q) gene polymorphism and oropharyngeal tularemia (p tularemia in this study (p > 0.05).

The Human Gene SLC25A29, of Solute Carrier Family 25, Encodes a Mitochondrial Transporter of Basic Amino Acids*

Science.gov (United States)

Porcelli, Vito; Fiermonte, Giuseppe; Longo, Antonella; Palmieri, Ferdinando

2014-01-01

The human genome encodes 53 members of the solute carrier family 25 (SLC25), also called the mitochondrial carrier family, many of which have been shown to transport carboxylates, amino acids, nucleotides, and cofactors across the inner mitochondrial membrane, thereby connecting cytosolic and matrix functions. In this work, a member of this family, SLC25A29, previously reported to be a mitochondrial carnitine/acylcarnitine- or ornithine-like carrier, has been thoroughly characterized biochemically. The SLC25A29 gene was overexpressed in Escherichia coli, and the gene product was purified and reconstituted in phospholipid vesicles. Its transport properties and kinetic parameters demonstrate that SLC25A29 transports arginine, lysine, homoarginine, methylarginine and, to a much lesser extent, ornithine and histidine. Carnitine and acylcarnitines were not transported by SLC25A29. This carrier catalyzed substantial uniport besides a counter-exchange transport, exhibited a high transport affinity for arginine and lysine, and was saturable and inhibited by mercurial compounds and other inhibitors of mitochondrial carriers to various degrees. The main physiological role of SLC25A29 is to import basic amino acids into mitochondria for mitochondrial protein synthesis and amino acid degradation. PMID:24652292

The human gene SLC25A29, of solute carrier family 25, encodes a mitochondrial transporter of basic amino acids.

Science.gov (United States)

Porcelli, Vito; Fiermonte, Giuseppe; Longo, Antonella; Palmieri, Ferdinando

2014-05-09

The human genome encodes 53 members of the solute carrier family 25 (SLC25), also called the mitochondrial carrier family, many of which have been shown to transport carboxylates, amino acids, nucleotides, and cofactors across the inner mitochondrial membrane, thereby connecting cytosolic and matrix functions. In this work, a member of this family, SLC25A29, previously reported to be a mitochondrial carnitine/acylcarnitine- or ornithine-like carrier, has been thoroughly characterized biochemically. The SLC25A29 gene was overexpressed in Escherichia coli, and the gene product was purified and reconstituted in phospholipid vesicles. Its transport properties and kinetic parameters demonstrate that SLC25A29 transports arginine, lysine, homoarginine, methylarginine and, to a much lesser extent, ornithine and histidine. Carnitine and acylcarnitines were not transported by SLC25A29. This carrier catalyzed substantial uniport besides a counter-exchange transport, exhibited a high transport affinity for arginine and lysine, and was saturable and inhibited by mercurial compounds and other inhibitors of mitochondrial carriers to various degrees. The main physiological role of SLC25A29 is to import basic amino acids into mitochondria for mitochondrial protein synthesis and amino acid degradation.

A single base deletion in the SLC45A2 gene in a Bullmastiff with oculocutaneous albinism.

Science.gov (United States)

Caduff, M; Bauer, A; Jagannathan, V; Leeb, T

2017-10-01

Oculocutaneous albinism type 4 (OCA4) in humans and similar phenotypes in many animal species are caused by variants in the SLC45A2 gene, encoding a putative sugar transporter. In dog, two independent SLC45A2 variants are known that cause oculocutaneous albinism in Doberman Pinschers and several small dog breeds respectively. For the present study, we investigated a Bullmastiff with oculocutaneous albinism. The affected dog was highly inbred and resulted from the mating of a sire to its own grandmother. We obtained whole genome sequence data from the affected dog and searched specifically for variants in candidate genes known to cause albinism. We detected a single base deletion in exon 6 of the SLC45A2 gene (NM_001037947.1:c.1287delC) that has not been reported thus far. This deletion is predicted to result in an early premature stop codon. It was confirmed by Sanger sequencing and perfectly co-segregated with the phenotype in the available family members. We genotyped 174 unrelated dogs from diverse breeds, all of which were homozygous wildtype. We therefore suggest that SLC45A2:c.1287delC causes the observed oculocutaneous albinism in the affected Bullmastiff. © 2017 Stichting International Foundation for Animal Genetics.

Risk and protective genetic variants in suicidal behaviour: association with SLC1A2, SLC1A3, 5-HTR1B &NTRK2 polymorphisms.

LENUS (Irish Health Repository)

Murphy, Therese M

2012-02-01

BACKGROUND: Suicidal behaviour is known to aggregate in families. Patients with psychiatric disorders are at higher risk for suicide attempts (SA), however protective and risk genetic variants for suicide appear to be independent of underlying psychiatric disorders. Here we investigate genetic variants in genes important for neurobiological pathways linked to suicidal behaviour and\\/or associated endophenotypes, for association with SA among patients with co-existing psychiatric illness. Selected gene-gene and gene-environment interactions were also tested. METHODS: DNA was obtained from bloods of 159 patients (76 suicide attempters and 83 non-attempters), who were profiled for DSM-IV Axis I psychiatric diagnosis. Twenty-eight single nucleotide polymorphisms (SNPs) from 18 candidate genes (COMT, 5-HT2A, 5-HT1A, 5-HTR1B, TPH1, MAO-A, TPH2, DBH, CNR1, BDNF, ABCG1, GABRA5, GABRG2, GABRB2, SLC1A2, SLC1A3, NTRK2, CRHR1) were genotyped. Genotyping was performed by KBioscience. Tests of association between genetic variants and SA were conducted using Chi squared and Armitage Trend tests. Binary logistical regression analyses were performed to evaluate the contribution of individual genetic variants to the prediction of SA, and to examine SNPs for potential gene-gene and gene-environment interactions. RESULTS: Our analysis identified 4 SNPs (rs4755404, rs2269272, rs6296 and rs1659400), which showed evidence of association with SA compared to a non-attempter control group. We provide evidence of a 3-locus gene-gene interaction, and a putative gene-environment interaction, whereby genetic variation at the NTRK2 locus may moderate the risk associated with history of childhood abuse. CONCLUSION: Preliminary findings suggest that allelic variability in SLC1A2\\/3, 5-HTR1B and NTRK2 may be relevant to the underlying diathesis for suicidal acts.

Lack of SLC2A1 (glucose transporter 1) mutations in 30 Italian patients with alternating hemiplegia of childhood.

Science.gov (United States)

De Grandis, Elisa; Stagnaro, Michela; Biancheri, Roberta; Giannotta, Melania; Gobbi, Giuseppe; Traverso, Monica; Veneselli, Edvige; Zara, Federico

2013-07-01

Alternating hemiplegia of childhood is a rare, predominantly sporadic disorder. Diagnosis is clinical, and little is known about genetics. Glucose transporter 1 deficiency syndrome shares with alternating hemiplegia of childhood paroxysmal and nonparoxysmal symptoms. The aim of the study was to investigate glucose transporter 1 mutations in 30 Italian patients. Genetic material was analyzed by DNA amplification and glucose transporter 1 region sequencing. Mutational analysis findings of the SLC2A1 gene were negative in all patients. The pattern of movement disorders was reviewed. Interictal dystonia and multiple paroxysmal events were typical of alternating hemiplegia of childhood. In conclusion, alternating hemiplegia of childhood is a heterogeneous clinical condition, and although glucose transporter 1 deficiency can represent an undiagnosed cause of this disorder, mutational analysis is not routinely recommended. Alternatively, a careful clinical analysis and the 3-O-methyl-D-glucose uptake test can allow prompt identification of a subgroup of patients with alternating hemiplegia of childhood treatable with a ketogenic diet.

Association study of serotonin transporter SLC6A4 gene with Chinese Han irritable bowel syndrome.

Directory of Open Access Journals (Sweden)

Jing Yuan

Full Text Available OBJECTIVE: Irritable bowel syndrome (IBS is a common clinical gastrointestinal dysfunction disorders. 5-sertonon (5-hydroxytryptamine, 5-HT is a very important neurotransmitter, which is involved in gastrointestinal motion and sensation. Solute carrier family 6 member 4 (SLC6A4 gene encode serotonin transporter (SERT which function is to rapidly reuptake the most of 5-HT. Therefore, it is needed to explore the association between SLC6A4 gene polymorphisms and IBS. METHODS: 119 patients and 238 healthy controls were administrated to detect the SLC6A4 gene polymorphisms including 5-HT-transporter-gene-linked polymorphic region (5-HTTLPR, variable number of tandem repeats (VNTRs and three selected tag Single Nucleotide Polymorphisms (SNPs rs1042173, rs3794808, rs2020936 by using polymerase chain reaction (PCR and TaqMan® SNP Genotyping. RESULTS: There were significant difference for 5-HTTLPR between IBS and control groups (X2 = 106.168, P<0.0001. In control group, genotypes were mainly L/L (58.4%, however, the genotypes in IBS were S/S (37.8%. The significant difference was shown in D-IBS subjects when compared to the controls (X(2 = 50.850, P<0.0001 for 5-HTTLPR. For STin2 VNTR, rs1042173, rs3794808, and rs2020936 polymorphisms, there were no any significant differences between IBS and control groups. There were no statistical significantly haplotypes for 5-HTTLPR, VNTRs and the three SNPs between IBS and controls. CONCLUSION: The S allele in 5-HTTLPR was a susceptible allele with Chinese Han IBS, but other associations of VNTRs, three selected Tag SNPs and positive haplotype with IBS were not found. It is indicated that much research are needed to study the relationship between other polymorphisms in SLC6A4 gene and IBS.

SLC37A1 and SLC37A2 are phosphate-linked, glucose-6-phosphate antiporters.

Directory of Open Access Journals (Sweden)

Chi-Jiunn Pan

Full Text Available Blood glucose homeostasis between meals depends upon production of glucose within the endoplasmic reticulum (ER of the liver and kidney by hydrolysis of glucose-6-phosphate (G6P into glucose and phosphate (P(i. This reaction depends on coupling the G6P transporter (G6PT with glucose-6-phosphatase-α (G6Pase-α. Only one G6PT, also known as SLC37A4, has been characterized, and it acts as a P(i-linked G6P antiporter. The other three SLC37 family members, predicted to be sugar-phosphate:P(i exchangers, have not been characterized functionally. Using reconstituted proteoliposomes, we examine the antiporter activity of the other SLC37 members along with their ability to couple with G6Pase-α. G6PT- and mock-proteoliposomes are used as positive and negative controls, respectively. We show that SLC37A1 and SLC37A2 are ER-associated, P(i-linked antiporters, that can transport G6P. Unlike G6PT, neither is sensitive to chlorogenic acid, a competitive inhibitor of physiological ER G6P transport, and neither couples to G6Pase-α. We conclude that three of the four SLC37 family members are functional sugar-phosphate antiporters. However, only G6PT/SLC37A4 matches the characteristics of the physiological ER G6P transporter, suggesting the other SLC37 proteins have roles independent of blood glucose homeostasis.

Molecular Properties of Drugs Interacting with SLC22 Transporters OAT1, OAT3, OCT1, and OCT2: A Machine-Learning Approach.

Science.gov (United States)

Liu, Henry C; Goldenberg, Anne; Chen, Yuchen; Lun, Christina; Wu, Wei; Bush, Kevin T; Balac, Natasha; Rodriguez, Paul; Abagyan, Ruben; Nigam, Sanjay K

2016-10-01

Statistical analysis was performed on physicochemical descriptors of ∼250 drugs known to interact with one or more SLC22 "drug" transporters (i.e., SLC22A6 or OAT1, SLC22A8 or OAT3, SLC22A1 or OCT1, and SLC22A2 or OCT2), followed by application of machine-learning methods and wet laboratory testing of novel predictions. In addition to molecular charge, organic anion transporters (OATs) were found to prefer interacting with planar structures, whereas organic cation transporters (OCTs) interact with more three-dimensional structures (i.e., greater SP3 character). Moreover, compared with OAT1 ligands, OAT3 ligands possess more acyclic tetravalent bonds and have a more zwitterionic/cationic character. In contrast, OCT1 and OCT2 ligands were not clearly distinquishable form one another by the methods employed. Multiple pharmacophore models were generated on the basis of the drugs and, consistent with the machine-learning analyses, one unique pharmacophore created from ligands of OAT3 possessed cationic properties similar to OCT ligands; this was confirmed by quantitative atomic property field analysis. Virtual screening with this pharmacophore, followed by transport assays, identified several cationic drugs that selectively interact with OAT3 but not OAT1. Although the present analysis may be somewhat limited by the need to rely largely on inhibition data for modeling, wet laboratory/in vitro transport studies, as well as analysis of drug/metabolite handling in Oat and Oct knockout animals, support the general validity of the approach-which can also be applied to other SLC and ATP binding cassette drug transporters. This may make it possible to predict the molecular properties of a drug or metabolite necessary for interaction with the transporter(s), thereby enabling better prediction of drug-drug interactions and drug-metabolite interactions. Furthermore, understanding the overlapping specificities of OATs and OCTs in the context of dynamic transporter tissue

Epigenetic adaptation of the placental serotonin transporter gene (SLC6A4 to gestational diabetes mellitus.

Directory of Open Access Journals (Sweden)

Sofia Blazevic

Full Text Available We tested the hypothesis that gestational diabetes mellitus (GDM alters the DNA methylation pattern of the fetal serotonin transporter gene (SLC6A4, and examined the functional relevance of DNA methylation for regulation of the SLC6A4 expression in the human placenta. The study included 50 mother-infant pairs. Eighteen mothers were diagnosed with GDM and 32 had normal glucose tolerance (NGT. All neonates were of normal birth weight and born at term by planned Cesarean section. DNA and RNA were isolated from samples of tissue collected from the fetal side of the placenta immediately after delivery. DNA methylation was quantified at 7 CpG sites within the SLC6A4 distal promoter region using PCR amplification of bisulfite treated DNA and subsequent DNA sequencing. SLC6A4 mRNA levels were measured by reverse transcription-quantitative PCR (RT-qPCR. Functional SLC6A4 polymorphisms (5HTTLPR, STin2, rs25531 were genotyped using standard PCR-based procedures. Average DNA methylation across the 7 analyzed loci was decreased in the GDM as compared to the NGT group (by 27.1%, p = 0.037 and negatively correlated, before and after adjustment for potential confounder/s, with maternal plasma glucose levels at the 24th to 28th week of gestation (p0.05. The results suggest that DNA methylation of the fetal SLC6A4 gene is sensitive to the maternal metabolic state in pregnancy. They also indicate a predominant role of epigenetic over genetic mechanisms in the regulation of SLC6A4 expression in the human placenta. Longitudinal studies in larger cohorts are needed to verify these results and determine to which degree placental SLC6A4 changes may contribute to long-term outcomes of infants exposed to GDM.

Genetic polymorphisms and haplotypes of the organic cation transporter 1 gene (SLC22A1 in the Xhosa population of South Africa

Directory of Open Access Journals (Sweden)

Clifford Jacobs

2014-06-01

Full Text Available Human organic cation transporter 1 is primarily expressed in hepatocytes and mediates the electrogenic transport of various endogenous and exogenous compounds, including clinically important drugs. Genetic polymorphisms in the gene coding for human organic cation transporter 1, SLC22A1, are increasingly being recognized as a possible mechanism explaining the variable response to clinical drugs, which are substrates for this transporter. The genotypic and allelic distributions of 19 nonsynonymous and one intronic SLC22A1 single nucleotide polymorphisms were determined in 148 healthy Xhosa participants from South Africa, using a SNAPshot® multiplex assay. In addition, haplotype structure for SLC22A1 was inferred from the genotypic data. The minor allele frequencies for S14F (rs34447885, P341L (rs2282143, V519F (rs78899680, and the intronic variant rs622342 were 1.7%, 8.4%, 3.0%, and 21.6%, respectively. None of the participants carried the variant allele for R61C (rs12208357, C88R (rs55918055, S189L (rs34104736, G220V (rs36103319, P283L (rs4646277, R287G (rs4646278, G401S (rs34130495, M440I (rs35956182, or G465R (rs34059508. In addition, no variant alleles were observed for A306T (COSM164365, A413V (rs144322387, M420V (rs142448543, I421F (rs139512541, C436F (rs139512541, V501E (rs143175763, or I542V (rs137928512 in the population. Eight haplotypes were inferred from the genotypic data. This study reports important genetic data that could be useful for future pharmacogenetic studies of drug transporters in the indigenous Sub-Saharan African populations.

Genetic analysis of the GLUT10 glucose transporter (SLC2A10 polymorphisms in Caucasian American type 2 diabetes

Directory of Open Access Journals (Sweden)

Mychaleckyj Josyf C

2005-12-01

Full Text Available Abstract Background GLUT10 (gene symbol SLC2A10 is a facilitative glucose transporter within the type 2 diabetes (T2DM-linked region on chromosome 20q12-13.1. Therefore, we evaluated GLUT10 as a positional candidate gene for T2DM in Caucasian Americans. Methods Twenty SNPs including 4 coding, 10 intronic and 6 5' and 3' to the coding sequence were genotyped across a 100 kb region containing the SLC2A10 gene in DNAs from 300 T2DM cases and 310 controls using the Sequenom MassArray Genotyping System. Allelic association was evaluated, and linkage disequilibrium (LD and haplotype structure of SLC2A10 were also determined to assess whether any specific haplotypes were associated with T2DM. Results Of these variants, fifteen had heterozygosities greater than 0.80 and were analyzed further for association with T2DM. No evidence of significant association was observed for any variant with T2DM (all P ≥ 0.05, including Ala206Thr (rs2235491 which was previously reported to be associated with fasting insulin. Linkage disequilibrium analysis suggests that the SLC2A10 gene is contained in a single haplotype block of 14 kb. Haplotype association analysis with T2DM did not reveal any significant differences between haplotype frequencies in T2DM cases and controls. Conclusion From our findings, we can conclude that sequence variants in or near GLUT10 are unlikely to contribute significantly to T2DM in Caucasian Americans.

A haplotype of the norepinephrine transporter gene (SLC6A2) is associated with visual memory in attention-deficit/hyperactivity disorder.

Science.gov (United States)

Shang, Chi-Yung; Chiang, Huey-Ling; Gau, Susan Shur-Fen

2015-04-03

Attention-deficit/hyperactivity disorder (ADHD) is a common heritable childhood-onset psychiatric disorder with impaired visual memory. Based on the evidence from treatment effect of atomoxetine, which interacts directly with the norepinephrine transporter, on visual memory in children with ADHD, this study examined the linkage disequilibrium structure of the norepinephrine transporter gene (SLC6A2) and the association between SLC6A2 and ADHD and visual memory, a promising endophenotype for ADHD. This family-based association sample consisted of 382 probands with DSM-IV ADHD and their family members (n=1298 in total) of Han Chinese in Taiwan. Visual memory was assessed by the Pattern Recognition Memory (PRM) and Spatial Recognition Memory (SRM) tasks of the Cambridge Neuropsychological Test Automated Battery (CANTAB). We screened 21 polymorphisms across SLC6A2 and used the Family-Based Association Test (FBAT) to test the associations of SLC6A2 polymorphisms with ADHD and the PRM and SRM measures. In haplotype analyses, a haplotype rs36011 (T)/rs1566652 (G) was significantly associated with ADHD (minimal p=0.045) after adjustment for multiple testing. In quantitative analyses, this TG haplotype also demonstrated significant associations with visual memory measures, including mean latency of correct responses in PRM (minimal p=0.019), total correct responses in PRM (minimal p=0.018), and total correct responses in SRM (minimal p=0.015). Our novel finding of the haplotype rs36011 (T)/rs1566652 (G) as a novel genetic marker involved in both ADHD disease susceptibility and visual memory suggests that allelic variations in SLC6A2 could provide insight into the pathways leading from genotype to phenotype of ADHD. Copyright © 2014 Elsevier Inc. All rights reserved.

Additive composite ABCG2, SLC2A9 and SLC22A12 scores of high-risk alleles with alcohol use modulate gout risk.

Science.gov (United States)

Tu, Hung-Pin; Chung, Chia-Min; Min-Shan Ko, Albert; Lee, Su-Shin; Lai, Han-Ming; Lee, Chien-Hung; Huang, Chung-Ming; Liu, Chiu-Shong; Ko, Ying-Chin

2016-09-01

The aim of the present study was to evaluate the contribution of urate transporter genes and alcohol use to the risk of gout/tophi. Eight variants of ABCG2, SLC2A9, SLC22A12, SLC22A11 and SLC17A3 were genotyped in male individuals in a case-control study with 157 gout (33% tophi), 106 asymptomatic hyperuricaemia and 295 control subjects from Taiwan. The multilocus profiles of the genetic risk scores for urate gene variants were used to evaluate the risk of asymptomatic hyperuricaemia, gout and tophi. ABCG2 Q141K (T), SLC2A9 rs1014290 (A) and SLC22A12 rs475688 (C) under an additive model and alcohol use independently predicted the risk of gout (respective odds ratio for each factor=2.48, 2.03, 1.95 and 2.48). The additive composite Q141K, rs1014290 and rs475688 scores of high-risk alleles were associated with gout risk (Pgout and tophi risk (P for interaction=0.0452, 0.0033). The synergistic effect of genetic urate score 5-6 and alcohol use indicates that these combined factors correlate with gout and tophi occurrence.

Sequence variation and linkage disequilibrium in the GABA transporter-1 gene (SLC6A1 in five populations: implications for pharmacogenetic research

Directory of Open Access Journals (Sweden)

Sughondhabirom Atapol

2007-10-01

Full Text Available Abstract Background GABA transporter-1 (GAT-1; genetic locus SLC6A1 is emerging as a novel target for treatment of neuropsychiatric disorders. To understand how population differences might influence strategies for pharmacogenetic studies, we identified patterns of genetic variation and linkage disequilibrium (LD in SLC6A1 in five populations representing three continental groups. Results We resequenced 12.4 kb of SLC6A1, including the promoters, exons and flanking intronic regions in African-American, Thai, Hmong, Finnish, and European-American subjects (total n = 40. LD in SLC6A1 was examined by genotyping 16 SNPs in larger samples. Sixty-three variants were identified through resequencing. Common population-specific variants were found in African-Americans, including a novel 21-bp promoter region variable number tandem repeat (VNTR, but no such variants were found in any of the other populations studied. Low levels of LD and the absence of major LD blocks were characteristic of all five populations. African-Americans had the highest genetic diversity. European-Americans and Finns did not differ in genetic diversity or LD patterns. Although the Hmong had the highest level of LD, our results suggest that a strategy based on the use of tag SNPs would not translate to a major improvement in genotyping efficiency. Conclusion Owing to the low level of LD and presence of recombination hotspots, SLC6A1 may be an example of a problematic gene for association and haplotype tagging-based genetic studies. The 21-bp promoter region VNTR polymorphism is a putatively functional candidate allele for studies focusing on variation in GAT-1 function in the African-American population.

The emerging physiological roles of the SLC14A family of urea transporters

Science.gov (United States)

Stewart, Gavin

2011-01-01

In mammals, urea is the main nitrogenous breakdown product of protein catabolism and is produced in the liver. In certain tissues, the movement of urea across cell membranes is specifically mediated by a group of proteins known as the SLC14A family of facilitative urea transporters. These proteins are derived from two distinct genes, UT-A (SLC14A2) and UT-B (SLC14A1). Facilitative urea transporters play an important role in two major physiological processes – urinary concentration and urea nitrogen salvaging. Although UT-A and UT-B transporters both have a similar basic structure and mediate the transport of urea in a facilitative manner, there are a number of significant differences between them. UT-A transporters are mainly found in the kidney, are highly specific for urea, have relatively lower transport rates and are highly regulated at both gene expression and cellular localization levels. In contrast, UT-B transporters are more widespread in their tissue location, transport both urea and water, have a relatively high transport rate, are inhibited by mercurial compounds and currently appear to be less acutely regulated. This review details the fundamental research that has so far been performed to investigate the function and physiological significance of these two types of urea transporters. PMID:21449978

Positive selection in the SLC11A1 gene in the family Equidae.

Science.gov (United States)

Bayerova, Zuzana; Janova, Eva; Matiasovic, Jan; Orlando, Ludovic; Horin, Petr

2016-05-01

Immunity-related genes are a suitable model for studying effects of selection at the genomic level. Some of them are highly conserved due to functional constraints and purifying selection, while others are variable and change quickly to cope with the variation of pathogens. The SLC11A1 gene encodes a transporter protein mediating antimicrobial activity of macrophages. Little is known about the patterns of selection shaping this gene during evolution. Although it is a typical evolutionarily conserved gene, functionally important polymorphisms associated with various diseases were identified in humans and other species. We analyzed the genomic organization, genetic variation, and evolution of the SLC11A1 gene in the family Equidae to identify patterns of selection within this important gene. Nucleotide SLC11A1 sequences were shown to be highly conserved in ten equid species, with more than 97 % sequence identity across the family. Single nucleotide polymorphisms (SNPs) were found in the coding and noncoding regions of the gene. Seven codon sites were identified to be under strong purifying selection. Codons located in three regions, including the glycosylated extracellular loop, were shown to be under diversifying selection. A 3-bp indel resulting in a deletion of the amino acid 321 in the predicted protein was observed in all horses, while it has been maintained in all other equid species. This codon comprised in an N-glycosylation site was found to be under positive selection. Interspecific variation in the presence of predicted N-glycosylation sites was observed.

Fructose Synthesis and Transport at the Uterine-Placental Interface of Pigs: Cell-Specific Localization of SLC2A5, SLC2A8, and Components of the Polyol Pathway.

Science.gov (United States)

Steinhauser, Chelsie B; Landers, McKinsey; Myatt, Louise; Burghardt, Robert C; Vallet, Jeffrey L; Bazer, Fuller W; Johnson, Greg A

2016-11-01

The fetal fluids and uterine flushings of pigs contain higher concentrations of fructose than glucose, but fructose is not detected in maternal blood. Fructose can be synthesized from glucose via enzymes of the polyol pathway, aldose reductase (AKR1B1) and sorbitol dehydrogenase (SORD), transported across cell membranes by solute carriers SLC2A5 and SLC2A8, and converted to fructose-1-phosphate by ketohexokinase (KHK). SLC2A8, SLC2A5, AKR1B1, SORD, and KHK mRNAs and proteins were analyzed using quantitative PCR and immunohistochemistry or in situ hybridization in endometria and placentae of cyclic and pregnant gilts, cyclic gilts injected with estrogen, and ovariectomized gilts injected with progesterone. Progesterone up-regulated SLC2A8 protein in uterine luminal (LE) and glandular epithelia during the peri-implantation period, and expression became exclusively placental, chorion and blood vessels, after Day 30. P4 up-regulated SLC2A5 mRNA in uterine LE and glandular epithelia after implantation, and the chorion expressed SLC2A5 between Days 30 and 85. AKR1B1 and SORD proteins localized to uterine LE during the peri-implantation period, but expression switched to chorion by Day 20 and was maintained through Day 85. Uterine expression of AKR1B1 mRNA was down-regulated by estrogen. KHK protein localized to trophectoderm/chorion throughout gestation. These results provide evidence that components for the conversion of glucose to fructose and for fructose transport are present at the uterine-placental interface of pigs. The shift in expression from LE to chorion during pregnancy suggests free-floating conceptuses are supported by fructose synthesized by the uterus, but after implantation, the chorion becomes self-sufficient for fructose synthesis and transport. © 2016 by the Society for the Study of Reproduction, Inc.

Differential SLC1A2 Promoter Methylation in Bipolar Disorder With or Without Addiction

Directory of Open Access Journals (Sweden)

Yun-Fang Jia

2017-07-01

Full Text Available While downregulation of excitatory amino acid transporter 2 (EAAT2, the main transporter removing glutamate from the synapse, has been recognized in bipolar disorder (BD, the underlying mechanisms of downregulation have not been elucidated. BD is influenced by environmental factors, which may, via epigenetic modulation of gene expression, differentially affect illness presentation. This study thus focused on epigenetic DNA methylation regulation of SLC1A2, encoding for EAAT2, in BD with variable environmental influences of addiction. High resolution melting PCR (HRM-PCR and thymine–adenine (TA cloning with sequence analysis were conducted to examine methylation of the promoter region of the SLC1A2. DNA was isolated from blood samples drawn from BD patients (N = 150 with or without addiction to alcohol, nicotine, or food, defined as binge eating, and matched controls (N = 32. In comparison to controls, the SLC1A2 promoter region was hypermethylated in BD without addiction but was hypomethylated in BD with addiction. After adjusting for age and sex, the association of methylation levels with nicotine addiction (p = 0.0009 and binge eating (p = 0.0002 remained significant. Consistent with HRM-PCR, direct sequencing revealed increased methylation in CpG site 6 in BD, but decreased methylation in three CpG sites (6, 48, 156 in BD with alcohol and nicotine addictions. These results suggest that individual point methylation within the SLC1A2 promoter region may be modified by exogenous addiction and may have a potential for developing clinically valuable epigenetic biomarkers for BD diagnosis and monitoring.

Variants in SLC18A3, vesicular acetylcholine transporter, cause congenital myasthenic syndrome

NARCIS (Netherlands)

O'Grady, Gina L.; Verschuuren, Corien; Yuen, Michaela; Webster, Richard; Menezes, Manoj; Fock, Johanna M.; Pride, Natalie; Best, Heather A.; Damm, Tatiana Benavides; Turner, Christian; Lek, Monkol; Engel, Andrew G.; North, Kathryn N.; Clarke, Nigel F.; MacArthur, Daniel G.; Kamsteeg, Erik-Jan; Cooper, Sandra T.

2016-01-01

Objective: To describe the clinical and genetic characteristics of presynaptic congenital myasthenic syndrome secondary to biallelic variants in SLC18A3. Methods: Individuals from 2 families were identified with biallelic variants in SLC18A3, the gene encoding the vesicular acetylcholine transporter

Riboflavin uptake transporter Slc52a2 (RFVT2) is upregulated in the mouse mammary gland during lactation.

Science.gov (United States)

Wu, Alex Man Lai; Dedina, Liana; Dalvi, Pooja; Yang, Mingdong; Leon-Cheon, John; Earl, Brian; Harper, Patricia A; Ito, Shinya

2016-04-01

While it is well recognized that riboflavin accumulates in breast milk as an essential vitamin for neonates, transport mechanisms for its milk excretion are not well characterized. The multidrug efflux transporter ABCG2 in the apical membrane of milk-producing mammary epithelial cells (MECs) is involved with riboflavin excretion. However, it is not clear whether MECs possess other riboflavin transport systems, which may facilitate its basolateral uptake into MECs. We report here that transcripts encoding the second (SLC52A2) and third (SLC52A3) member of the recently discovered family of SLC52A riboflavin uptake transporters are expressed in milk fat globules from human breast milk. Furthermore, Slc52a2 and Slc52a3 mRNA are upregulated in the mouse mammary gland during lactation. Importantly, the induction ofSlc52a2, which was the major Slc52a riboflavin transporter in the lactating mammary gland, was also observed at the protein level. Subcellular localization studies showed that green fluorescent protein-tagged mouse SLC52A2 mainly localized to the cell membrane, with no preferential distribution to the apical or basolateral membrane in polarized kidney MDCK cells. These results strongly implicate a potential role for SLC52A2 in riboflavin uptake by milk-producing MECs, a critical step in the transfer of riboflavin into breast milk. Copyright © 2016 the American Physiological Society.

Differential expression of the Slc4 bicarbonate transporter family in murine corneal endothelium and cell culture.

Science.gov (United States)

Shei, William; Liu, Jun; Htoon, Hla M; Aung, Tin; Vithana, Eranga N

2013-01-01

To characterize the relative expression levels of all the solute carrier 4 (Slc4) transporter family members (Slc4a1-Slc4a11) in murine corneal endothelium using real-time quantitative (qPCR), to identify further important members besides Slc4a11 and Slc4a4, and to explore how close to the baseline levels the gene expressions remain after cells have been subjected to expansion and culture. Descemet's membrane-endothelial layers of 8-10-week-old C57BL6 mice were stripped from corneas and used for both primary cell culture and direct RNA extraction. Total RNA (from uncultured cells as well as cultured cells at passages 2 and 7) was reverse transcribed, and the cDNA was used for real time qPCR using specific primers for all the Slc4 family members. The geNorm method was applied to determine the most stable housekeeping genes and normalization factor, which was calculated from multiple housekeeping genes for more accurate and robust quantification. qPCR analyses revealed that all Slc4 bicarbonate transporter family members were expressed in mouse corneal endothelium. Slc4a11 showed the highest expression, which was approximately three times higher than that of Slc4a4 (3.4±0.3; p=0.004). All Slc4 genes were also expressed in cultured cells, and interestingly, the expression of Slc4a11 in cultured cells was significantly reduced by approximately 20-fold (0.05±0.001; p=0.000001) in early passage and by approximately sevenfold (0.14±0.002; p=0.000002) in late passage cells. Given the known involvement of SLC4A4 and SLC4A11 in corneal dystrophies, we speculate that the other two highly expressed genes in the uncultured corneal endothelium, SLC4A2 and SLC4A7, are worthy of being considered as potential candidate genes for corneal endothelial diseases. Moreover, as cell culture can affect expression levels of Slc4 genes, caution and careful design of experiments are necessary when undertaking studies of Slc4-mediated ion transport in cultured cells.

Identification of two novel mutations in the SLC45A2 gene in a Hungarian pedigree affected by unusual OCA type 4.

Science.gov (United States)

Tóth, Lola; Fábos, Beáta; Farkas, Katalin; Sulák, Adrienn; Tripolszki, Kornélia; Széll, Márta; Nagy, Nikoletta

2017-03-15

Oculocutaneous albinism (OCA) is a clinically and genetically heterogenic group of pigmentation abnormalities. OCA type IV (OCA4, OMIM 606574) develops due to homozygous or compound heterozygous mutations in the solute carrier family 45, member 2 (SLC45A2) gene. This gene encodes a membrane-associated transport protein, which regulates tyrosinase activity and, thus, melanin content by changing melanosomal pH and disrupting the incorporation of copper into tyrosinase. Here we report two Hungarian siblings affected by an unusual OCA4 phenotype. After genomic DNA was isolated from peripheral blood of the patients, the coding regions of the SLC45A2 gene were sequenced. In silico tools were applied to identify the functional impact of the newly detected mutations. Direct sequencing of the SLC45A2 gene revealed two novel, heterozygous mutations, one missense (c.1226G > A, p.Gly409Asp) and one nonsense (c.1459C > T, p.Gln437*), which were present in both patients, suggesting the mutations were compound heterozygous. In silico tools suggest that these variations are disease causing mutations. The newly identified mutations may affect the transmembrane domains of the protein, and could impair transport function, resulting in decreases in both melanosomal pH and tyrosinase activity. Our study provides expands on the mutation spectrum of the SLC45A2 gene and the genetic background of OCA4.

The dopamine transporter protein gene (SLC6A3): Primary linage mapping and linkage studies in Tourette syndrome

Energy Technology Data Exchange (ETDEWEB)

Gelernter, J.; Kruger, S.D.; Pakstis, A.J. [Yale Univ., New Haven, CT (United States)]|[West Haven Veterans Affairs Medical Center, CT (United States)] [and others

1995-12-10

The dopamine transporter, the molecule responsible for presynaptic reuptake of dopamine and a major site of action of psychostimulant drugs, including cocaine, is encoded by locus SLC6A3 (alias DAT1). The protein`s actions and DAT`s specific localization to dopaminergic neurons make it a candidate gene for several psychiatric illnesses. SLC6A3 has been mapped to distal chromosome 5p, using physical methods. Genetic linkage methods were used to place SLC6A3 in the genetic linkage map. Four extended pedigrees (one of which overlaps with CEPH) were typed. Linkage with Tourette syndrome (TS) was also examined. SLC6A3 showed close linkage with several markers previously mapped to distal chromosome 5p, including D5S11 (Z{sub max} = 16.0, {theta}{sub M} = {theta}{sub F} = 0.03, results from four families) and D5S678 (Z{sub max} = 7.84, {theta}{sub M} = {theta}{sub F} = 0, results from two families). Observed crossovers established that SLC6A3 is a distal marker close to D5S10 and D5S678, but these three distal markers could not be ordered. Linkage between TS and SLC6A3 could be excluded independently in two branches of a large kindred segregating TS; the lod score in a third family was also negative, but not significant. Cumulative results show a lod score of -6.2 at {theta} = 0 and of -3.9 at {theta} = 0.05 (dominant model, narrow disease definition). SLC6A3 thus maps to distal chromosome 5p by linkage analysis, in agreement with previous physical mapping data. A mutation at SLC6A3 is not causative for TS in the two large families that generated significant negative lod scores (if the parameters of our analyses were correct) and is unlikely to be causative in the family that generated a negative lod score that did not reach significance. These results do not exclude a role for the dopamine transporter in influencing risk for TS in combination with other loci. 23 refs., 1 fig., 2 tabs.

Impact of genetic polymorphisms of SLC2A2, SLC2A5, and KHK on metabolic phenotypes in hypertensive individuals.

Directory of Open Access Journals (Sweden)

MyPhuong T Le

Full Text Available In the past few decades, consumption of added sugars has increased dramatically. Studies have linked high sugar intake with increased risk for a number of diseases. Importantly, fructose, a component of sugar, has been linked with the development of features of metabolic syndrome. This study determined if single nucleotide polymorphisms in genes involved in fructose transport (solute carrier family 2 facilitated glucose transporter, member 2 (SLC2A2 and solute carrier family 2 facilitated glucose/fructose transporter, member 5 (SLC2A5 and metabolism (ketohexokinase (KHK affect inter-individual variability in metabolic phenotypes, such as increased serum uric acid levels.The influence of SLC2A2, SLC2A5, and KHK SNPs on metabolic phenotypes was tested in 237 European Americans and 167 African Americans from the Pharmacogenomic Evaluation and Antihypertensive Responses (PEAR study. Using baseline untreated fasting data, associations were considered significant if p≤0.005. These SNPs were then evaluated for potential replication (p≤0.05 using data from the Genetic Epidemiology of Responses to Antihypertensives (GERA studies.SLC2A5 rs5438 was associated with an increase in serum uric acid in European American males. However, we were unable to replicate the association in GERA. The minor allele of SLC2A2 rs8192675 showed an association with lower high-density lipoproteins in European Americans (A/A: 51.0 mg/dL, A/G: 47.0 mg/dL, G/G: 41.5 mg/dL, p = 0.0034 in PEAR. The association between rs8192675 and lower high-density lipoproteins was replicated in the combined European American GERA study samples (A/A: 47.6 mg/dL, A/G: 48.6 mg/dL, G/G: 41.9 mg/dL, p = 0.0315.The association between SLC2A2 rs8192675 and high-density lipoproteins suggests the polymorphism may play a role in influencing high-density lipoproteins and thus metabolic risk of cardiovascular disease.

Metformin Is a Substrate and Inhibitor of the Human Thiamine Transporter, THTR-2 (SLC19A3).

Science.gov (United States)

Liang, Xiaomin; Chien, Huan-Chieh; Yee, Sook Wah; Giacomini, Marilyn M; Chen, Eugene C; Piao, Meiling; Hao, Jia; Twelves, Jolyn; Lepist, Eve-Irene; Ray, Adrian S; Giacomini, Kathleen M

2015-12-07

The biguanide metformin is widely used as first-line therapy for the treatment of type 2 diabetes. Predominately a cation at physiological pH's, metformin is transported by membrane transporters, which play major roles in its absorption and disposition. Recently, our laboratory demonstrated that organic cation transporter 1, OCT1, the major hepatic uptake transporter for metformin, was also the primary hepatic uptake transporter for thiamine, vitamin B1. In this study, we tested the reverse, i.e., that metformin is a substrate of thiamine transporters (THTR-1, SLC19A2, and THTR-2, SLC19A3). Our study demonstrated that human THTR-2 (hTHTR-2), SLC19A3, which is highly expressed in the small intestine, but not hTHTR-1, transports metformin (Km = 1.15 ± 0.2 mM) and other cationic compounds (MPP(+) and famotidine). The uptake mechanism for hTHTR-2 was pH and electrochemical gradient sensitive. Furthermore, metformin as well as other drugs including phenformin, chloroquine, verapamil, famotidine, and amprolium inhibited hTHTR-2 mediated uptake of both thiamine and metformin. Species differences in the substrate specificity of THTR-2 between human and mouse orthologues were observed. Taken together, our data suggest that hTHTR-2 may play a role in the intestinal absorption and tissue distribution of metformin and other organic cations and that the transporter may be a target for drug-drug and drug-nutrient interactions.

Impaired riboflavin transport due to missense mutations in SLC52A2 causes Brown-Vialetto-Van Laere syndrome

OpenAIRE

Haack, Tobias B.; Makowski, Christine; Yao, Yoshiaki; Graf, Elisabeth; Hempel, Maja; Wieland, Thomas; Tauer, Ulrike; Ahting, Uwe; Mayr, Johannes A.; Freisinger, Peter; Yoshimatsu, Hiroki; Inui, Ken; Strom, Tim M.; Meitinger, Thomas; Yonezawa, Atsushi

2012-01-01

Brown-Vialetto-Van Laere syndrome (BVVLS [MIM 211530]) is a rare neurological disorder characterized by infancy onset sensorineural deafness and ponto-bulbar palsy. Mutations in SLC52A3 (formerly C20orf54), coding for riboflavin transporter 2 (hRFT2), have been identified as the molecular genetic correlate in several individuals with BVVLS. Exome sequencing of just one single case revealed that compound heterozygosity for two pathogenic mutations in the SLC52A2 gene coding for riboflavin tran...

Alternative transcription of sodium/bicarbonate transporter SLC4A7 gene enhanced by single nucleotide polymorphisms.

Science.gov (United States)

Park, Hae Jeong; Lee, Soojung; Ju, Eunji; Jones, Jayre A; Choi, Inyeong

2017-03-01

Genome-wide association studies have identified the single nucleotide polymorphism (SNP) rs3278 in the human SLC4A7 gene as one of the marker loci for addiction vulnerability. This marker is located in an intron of the gene, and its genomic role has been unknown. In this study, we examined rs3278 and three adjacent SNPs prevalent in alcoholics for their effects on an alternative promoter that would lead to the production of the NH 2 -terminally truncated protein NBCn1ΔN450, missing the first 450 amino acids. Analysis of the transcription start site database and a promoter prediction algorithm identified a cluster of three promoters in intron 7 and two short CpG-rich sites in intron 6. The promoter closest to rs3278 showed strong transcription activity in luciferase reporter gene assays. Major-to-minor allele substitution at rs3278 resulted in increased transcription activity. Equivalent substitutions at adjacent rs3772723 (intron 7) and rs13077400 (exon 8) had negligible effect; however, the substitution at nonsynonymous rs3755652 (exon 8) increased the activity by more than twofold. The concomitant substitution at rs3278/rs3755652 produced an additive effect. The rs3755652 had more profound effects on the promoter than the upstream regulatory CpG sites. The amino acid change E326K caused by rs3755652 had negligible effect on transporter function. In HEK 293 cells, NBCn1ΔN450 was expressed in plasma membranes, but at significantly lower levels than the nontruncated NBCn1-E. The pH change mediated by NBCn1ΔN450 was also low. We conclude that rs3278 and rs3755652 stimulate an alternative transcription of the SLC4A7 gene, increasing the production of a defective transporter. Copyright © 2017 the American Physiological Society.

Development of imatinib and dasatinib resistance: dynamics of expression of drug transporters ABCB1, ABCC1, ABCG2, MVP, and SLC22A1.

Science.gov (United States)

Gromicho, Marta; Dinis, Joana; Magalhães, Marta; Fernandes, Alexandra R; Tavares, Purificação; Laires, António; Rueff, José; Rodrigues, António Sebastião

2011-10-01

About 20% of patients with chronic myeloid leukemia (CML) do not respond to treatment with imatinib either initially or because of acquired resistance. To study the development of CML drug resistance, an in vitro experimental system comprising cell lines with different resistance levels was established by exposing K562 cells to increasing concentrations of imatinib and dasatinib anticancer agents. The mRNA levels of BCR- ABL1 and of genes involved in drug transport or redistribution (ABCB1, ABCC1, ABCC3, ABCG2, MVP, and SLC22A1) were measured and the ABL1 kinase domain sequenced. Results excluded BCR- ABL1 overexpression and mutations as relevant resistance mechanisms. Most studied transporters were overexpressed in the majority of resistant cell lines. Their expression pattern was dynamic: varying with resistance level and chronic drug exposure. Studied efflux transporters may have an important role at the initial stages of resistance, but after prolonged exposure and for higher doses of drugs other mechanisms might take place.

The Creatine Transporter Gene Paralogous at 16p11.2 Is Expressed in Human Brain

Directory of Open Access Journals (Sweden)

Nadia Bayou

2008-01-01

We report on the clinical, cytogenetic, and molecular findings in a boy with autism carrying a de novo translocation t(7;16(p22.1;p11.2. The chromosome 16 breakpoint disrupts the paralogous SLC6A8 gene also called SLC6A10 or CT2. Predicted translation of exons and RT-PCR analysis reveal specific expression of the creatine transporter paralogous in testis and brain. Several studies reported on the role of X-linked creatine transporter mutations in individuals with mental retardation, with or without autism. The existence of disruption in SLC6A8 paralogous gene associated with idiopathic autism suggests that this gene may be involved in the autistic phenotype in our patient.

Multicenter cohort association study of SLC2A1 single nucleotide polymorphisms and age-related macular degeneration

Science.gov (United States)

Baas, Dominique C.; Ho, Lintje; Tanck, Michael W.T.; Fritsche, Lars G.; Merriam, Joanna E.; van het Slot, Ruben; Koeleman, Bobby P.C.; Gorgels, Theo G.M.F.; van Duijn, Cornelia M.; Uitterlinden, André G.; de Jong, Paulus T.V.M.; Hofman, Albert; ten Brink, Jacoline B.; Vingerling, Johannes R.; Klaver, Caroline C.W.; Dean, Michael; Weber, Bernhard H. F.; Allikmets, Rando; Hageman, Gregory S.

2012-01-01

Purpose Age-related macular degeneration (AMD) is a major cause of blindness in older adults and has a genetically complex background. This study examines the potential association between single nucleotide polymorphisms (SNPs) in the glucose transporter 1 (SLC2A1) gene and AMD. SLC2A1 regulates the bioavailability of glucose in the retinal pigment epithelium (RPE), which might influence oxidative stress–mediated AMD pathology. Methods Twenty-two SNPs spanning the SLC2A1 gene were genotyped in 375 cases and 199 controls from an initial discovery cohort (the Amsterdam-Rotterdam-Netherlands study). Replication testing was performed in The Rotterdam Study (the Netherlands) and study populations from Würzburg (Germany), the Age Related Eye Disease Study (AREDS; United States), Columbia University (United States), and Iowa University (United States). Subsequently, a meta-analysis of SNP association was performed. Results In the discovery cohort, significant genotypic association between three SNPs (rs3754219, rs4660687, and rs841853) and AMD was found. Replication in five large independent (Caucasian) cohorts (4,860 cases and 4,004 controls) did not yield consistent association results. The genotype frequencies for these SNPs were significantly different for the controls and/or cases among the six individual populations. Meta-analysis revealed significant heterogeneity of effect between the studies. Conclusions No overall association between SLC2A1 SNPs and AMD was demonstrated. Since the genotype frequencies for the three SLC2A1 SNPs were significantly different for the controls and/or cases between the six cohorts, this study corroborates previous evidence that population dependent genetic risk heterogeneity in AMD exists. PMID:22509097

The role of SLC2A1 in early onset and childhood absence epilepsies

DEFF Research Database (Denmark)

Muhle, Hiltrud; Helbig, Ingo; Frøslev, Tobias Guldberg

2013-01-01

Early Onset Absence Epilepsy constitutes an Idiopathic Generalized Epilepsy with absences starting before the age of four years. Mutations in SLC2A1, encoding the glucose transporter, account for approximately 10% of EOAE cases. The role of SLC2A1 mutations in absence epilepsies with a later onset...

DNA methylation of amino acid transporter genes in the human placenta.

Science.gov (United States)

Simner, C; Novakovic, B; Lillycrop, K A; Bell, C G; Harvey, N C; Cooper, C; Saffery, R; Lewis, R M; Cleal, J K

2017-12-01

Placental transfer of amino acids via amino acid transporters is essential for fetal growth. Little is known about the epigenetic regulation of amino acid transporters in placenta. This study investigates the DNA methylation status of amino acid transporters and their expression across gestation in human placenta. BeWo cells were treated with 5-aza-2'-deoxycytidine to inhibit methylation and assess the effects on amino acid transporter gene expression. The DNA methylation levels of amino acid transporter genes in human placenta were determined across gestation using DNA methylation array data. Placental amino acid transporter gene expression across gestation was also analysed using data from publically available Gene Expression Omnibus data sets. The expression levels of these transporters at term were established using RNA sequencing data. Inhibition of DNA methylation in BeWo cells demonstrated that expression of specific amino acid transporters can be inversely associated with DNA methylation. Amino acid transporters expressed in term placenta generally showed low levels of promoter DNA methylation. Transporters with little or no expression in term placenta tended to be more highly methylated at gene promoter regions. The transporter genes SLC1A2, SLC1A3, SLC1A4, SLC7A5, SLC7A11 and SLC7A10 had significant changes in enhancer DNA methylation across gestation, as well as gene expression changes across gestation. This study implicates DNA methylation in the regulation of amino acid transporter gene expression. However, in human placenta, DNA methylation of these genes remains low across gestation and does not always play an obvious role in regulating gene expression, despite clear evidence for differential expression as gestation proceeds. Copyright © 2017. Published by Elsevier Ltd.

Missense mutation in exon 2 of SLC36A1 responsible for champagne dilution in horses.

Directory of Open Access Journals (Sweden)

Deborah Cook

2008-09-01

Full Text Available Champagne coat color in horses is controlled by a single, autosomal-dominant gene (CH. The phenotype produced by this gene is valued by many horse breeders, but can be difficult to distinguish from the effect produced by the Cream coat color dilution gene (CR. Three sires and their families segregating for CH were tested by genome scanning with microsatellite markers. The CH gene was mapped within a 6 cM region on horse chromosome 14 (LOD = 11.74 for theta = 0.00. Four candidate genes were identified within the region, namely SPARC [Secreted protein, acidic, cysteine-rich (osteonectin], SLC36A1 (Solute Carrier 36 family A1, SLC36A2 (Solute Carrier 36 family A2, and SLC36A3 (Solute Carrier 36 family A3. SLC36A3 was not expressed in skin tissue and therefore not considered further. The other three genes were sequenced in homozygotes for CH and homozygotes for the absence of the dilution allele (ch. SLC36A1 had a nucleotide substitution in exon 2 for horses with the champagne phenotype, which resulted in a transition from a threonine amino acid to an arginine amino acid (T63R. The association of the single nucleotide polymorphism (SNP with the champagne dilution phenotype was complete, as determined by the presence of the nucleotide variant among all 85 horses with the champagne dilution phenotype and its absence among all 97 horses without the champagne phenotype. This is the first description of a phenotype associated with the SLC36A1 gene.

Inhibition of intestinal bile acid transporter Slc10a2 improves triglyceride metabolism and normalizes elevated plasma glucose levels in mice.

Directory of Open Access Journals (Sweden)

Thomas Lundåsen

Full Text Available Interruption of the enterohepatic circulation of bile acids increases cholesterol catabolism, thereby stimulating hepatic cholesterol synthesis from acetate. We hypothesized that such treatment should lower the hepatic acetate pool which may alter triglyceride and glucose metabolism. We explored this using mice deficient of the ileal sodium-dependent BA transporter (Slc10a2 and ob/ob mice treated with a specific inhibitor of Slc10a2. Plasma TG levels were reduced in Slc10a2-deficient mice, and when challenged with a sucrose-rich diet, they displayed a reduced response in hepatic TG production as observed from the mRNA levels of several key enzymes in fatty acid synthesis. This effect was paralleled by a diminished induction of mature sterol regulatory element-binding protein 1c (Srebp1c. Unexpectedly, the SR-diet induced intestinal fibroblast growth factor (FGF 15 mRNA and normalized bile acid synthesis in Slc10a2-/- mice. Pharmacologic inhibition of Slc10a2 in diabetic ob/ob mice reduced serum glucose, insulin and TGs, as well as hepatic mRNA levels of Srebp1c and its target genes. These responses are contrary to those reported following treatment of mice with a bile acid binding resin. Moreover, when key metabolic signal transduction pathways in the liver were investigated, those of Mek1/2-Erk1/2 and Akt were blunted after treatment of ob/ob mice with the Slc10a2 inhibitor. It is concluded that abrogation of Slc10a2 reduces hepatic Srebp1c activity and serum TGs, and in the diabetic ob/ob model it also reduces glucose and insulin levels. Hence, targeting of Slc10a2 may be a promising strategy to treat hypertriglyceridemia and diabetes.

Changes in oil content of transgenic soybeans expressing the yeast SLC1 gene.

Science.gov (United States)

Rao, Suryadevara S; Hildebrand, David

2009-10-01

The wild type (Wt) and mutant form of yeast (sphingolipid compensation) genes, SLC1 and SLC1-1, have been shown to have lysophosphatidic acid acyltransferase (LPAT) activities (Nageic et al. in J Biol Chem 269:22156-22163, 1993). Expression of these LPAT genes was reported to increase oil content in transgenic Arabidopsis and Brassica napus. It is of interest to determine if the TAG content increase would also be seen in soybeans. Therefore, the wild type SLC1 was expressed in soybean somatic embryos under the control of seed specific phaseolin promoter. Some transgenic somatic embryos and in both T2 and T3 transgenic seeds showed higher oil contents. Compared to controls, the average increase in triglyceride values went up by 1.5% in transgenic somatic embryos. A maximum of 3.2% increase in seed oil content was observed in a T3 line. Expression of the yeast Wt LPAT gene did not alter the fatty acid composition of the seed oil.

Association between a genetic variant in the serotonin transporter gene (SLC6A4 and suicidal behavior in patients with schizophrenia

Directory of Open Access Journals (Sweden)

Lindholm Carlström Eva

2012-05-01

Full Text Available Abstract Background The serotonin (5-hydroxytryptamin; 5-HT system has a central role in the circuitry of cognition and emotions. Multiple lines of evidence suggest that genetic variation in the serotonin transporter gene (SLC6A4; 5-HTT is associated with schizophrenia and suicidal behavior. In this study, we wanted to elucidate whether SLC6A4 variations is involved in attempted suicide among patients with schizophrenia in a Scandinavian case–control sample. Methods Patients diagnosed with schizophrenia from three Scandinavian samples were assessed for presence or absence of suicide attempts, based on record reviews and interview data. Seven SLC6A4 single nucleotide polymorphisms (SNPs were genotyped in 837 schizophrenia patients and 1,473 control individuals. Association analyses and statistical evaluations were performed with the program UNPHASED (version 3.0.9. Results We observed an allele association between the SNP rs16965628, located in intron one of SLC6A4, and attempted suicide (adjusted p-value 0.01, among patients with schizophrenia. No association was found to a diagnosis of schizophrenia, when patients were compared to healthy control individuals. Conclusion The gene SLC6A4 appears to be involved in suicidal ideation among patients with schizophrenia. Independent replication is needed before more firm conclusions can be drawn.

Identification of novel mutations in HFE, HFE2, TfR2, and SLC40A1 genes in Chinese patients affected by hereditary hemochromatosis.

Science.gov (United States)

Wang, Yongwei; Du, Yali; Liu, Gang; Guo, Shanshan; Hou, Bo; Jiang, Xianyong; Han, Bing; Chang, Yanzhong; Nie, Guangjun

2017-04-01

Hereditary hemochromatosis (HH) is a group of inherited iron-overload disorders associated with pathogenic defects in the genes encoding hemochromatosis (HFE), hemojuvelin (HJV/HFE2), hepcidin (HAMP), transferrin receptor 2 (TfR2), and ferroportin (FPN1/SLC40A1) proteins, and the clinical features are well described. However, there have been only a few detailed reports of HH in Chinese populations. Thus, there is insufficient patient information for population-based analyses in Chinese populations or comparative studies among different ethical groups. In the current work, we describe eight Chinese cases of hereditary hemochromatosis. Gene sequencing results revealed eight mutations (five novel mutations) in HFE, HFE2, TfR2, and SLC40A1 genes in these Chinese HH patients. In addition, we used Polymorphism Phenotyping v2 (Polyphen), Sorting Intolerant From Tolerant (SIFT), and a sequence alignment program to predict the molecular consequences of missense mutations.

A novel variant in the SLC12A1 gene in two families with antenatal Bartter syndrome.

Science.gov (United States)

Breinbjerg, Anders; Siggaard Rittig, Charlotte; Gregersen, Niels; Rittig, Søren; Hvarregaard Christensen, Jane

2017-01-01

Bartter syndrome is an autosomal-recessive inherited disease in which patients present with hypokalaemia and metabolic alkalosis. We present two apparently nonrelated cases with antenatal Bartter syndrome type I, due to a novel variant in the SLC12A1 gene encoding the bumetanide-sensitive sodium-(potassium)-chloride cotransporter 2 in the thick ascending limb of the loop of Henle. Blood samples were received from the two cases and 19 of their relatives, and deoxyribonucleic acid was extracted. The coding regions of the SLC12A1 gene were amplified using polymerase chain reaction, followed by bidirectional direct deoxyribonucleic acid sequencing. Each affected child in the two families was homozygous for a novel inherited variant in the SLC12A1gene, c.1614T>A. The variant predicts a change from a tyrosine codon to a stop codon (p.Tyr538Ter). The two cases presented antenatally and at six months of age, respectively. The two cases were homozygous for the same variant in the SLC12A1 gene, but presented clinically at different ages. This could eventually be explained by the presence of other gene variants or environmental factors modifying the phenotypes. The phenotypes of the patients were similar to other patients with antenatal Bartter syndrome. ©2016 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Transcript levels of members of the SLC2 and SLC5 families of glucose transport proteins in eel swimbladder tissue: the influence of silvering and the influence of a nematode infection.

Science.gov (United States)

Schneebauer, Gabriel; Mauracher, David; Fiechtner, Birgit; Pelster, Bernd

2018-04-01

The rate of glucose metabolism has been shown to be correlated to glucose uptake in swimbladder gas gland cells. Therefore, it is assumed that in the European eel silvering, i.e., the preparation of the eel for the spawning migration to the Sargasso Sea, coincides with an enhanced capacity for glucose uptake. To test this hypothesis expression of all known glucose transport proteins has been assessed at the transcript level in yellow and in silver eels, and we also included Anguillicola crassus infected swimbladders. Glucose uptake by rete mirabile endothelial cells could be crucial for the countercurrent exchange capacity of the rete. Therefore, this tissue was also included in our analysis. The results revealed expression of ten different members of the slc2 family of glucose transporters, of four slc5 family members, and of kiaa1919 in gas gland tissue. Glucose transporters of the slc2 family were expressed at very high level, and slc2a1b made up about 80% of all slc2 family members, irrespective of the developmental state or the infection status of the eel. Overall, the slc5 family contributed to only about 8% of all detected glucose transport transcripts in gas gland tissue, and the slc2 family to more than 85%. In rete capillaries, the contribution of sodium-dependent glucose transporters was significantly higher, leaving only 66% for the slc2 family of glucose transporters. Neither silvering nor the infection status had a significant effect on the expression of glucose transporters in swimbladder gas gland tissue, suggesting that glucose metabolism of eel gas gland cells may not be related to transcriptional changes of glucose transport proteins.

Neurotransmitter Transporter-Like: a male germline-specific SLC6 transporter required for Drosophila spermiogenesis.

Directory of Open Access Journals (Sweden)

Nabanita Chatterjee

2011-01-01

Full Text Available The SLC6 class of membrane transporters, known primarily as neurotransmitter transporters, is increasingly appreciated for its roles in nutritional uptake of amino acids and other developmentally specific functions. A Drosophila SLC6 gene, Neurotransmitter transporter-like (Ntl, is expressed only in the male germline. Mobilization of a transposon inserted near the 3' end of the Ntl coding region yields male-sterile mutants defining a single complementation group. Germline transformation with Ntl cDNAs under control of male germline-specific control elements restores Ntl/Ntl homozygotes to normal fertility, indicating that Ntl is required only in the germ cells. In mutant males, sperm morphogenesis appears normal, with elongated, individualized and coiled spermiogenic cysts accumulating at the base of the testes. However, no sperm are transferred to the seminal vesicle. The level of polyglycylation of Ntl mutant sperm tubulin appears to be significantly lower than that of wild type controls. Glycine transporters are the most closely related SLC6 transporters to Ntl, suggesting that Ntl functions as a glycine transporter in developing sperm, where augmentation of the cytosolic pool of glycine may be required for the polyglycylation of the massive amounts of tubulin in the fly's giant sperm. The male-sterile phenotype of Ntl mutants may provide a powerful genetic system for studying the function of an SLC6 transporter family in a model organism.

Cystinuria Associated with Different SLC7A9 Gene Variants in the Cat.

Directory of Open Access Journals (Sweden)

Keijiro Mizukami

Full Text Available Cystinuria is a classical inborn error of metabolism characterized by a selective proximal renal tubular defect affecting cystine, ornithine, lysine, and arginine (COLA reabsorption, which can lead to uroliths and urinary obstruction. In humans, dogs and mice, cystinuria is caused by variants in one of two genes, SLC3A1 and SLC7A9, which encode the rBAT and bo,+AT subunits of the bo,+ basic amino acid transporter system, respectively. In this study, exons and flanking regions of the SLC3A1 and SLC7A9 genes were sequenced from genomic DNA of cats (Felis catus with COLAuria and cystine calculi. Relative to the Felis catus-6.2 reference genome sequence, DNA sequences from these affected cats revealed 3 unique homozygous SLC7A9 missense variants: one in exon 5 (p.Asp236Asn from a non-purpose-bred medium-haired cat, one in exon 7 (p.Val294Glu in a Maine Coon and a Sphinx cat, and one in exon 10 (p.Thr392Met from a non-purpose-bred long-haired cat. A genotyping assay subsequently identified another cystinuric domestic medium-haired cat that was homozygous for the variant originally identified in the purebred cats. These missense variants result in deleterious amino acid substitutions of highly conserved residues in the bo,+AT protein. A limited population survey supported that the variants found were likely causative. The remaining 2 sequenced domestic short-haired cats had a heterozygous variant at a splice donor site in intron 10 and a homozygous single nucleotide variant at a branchpoint in intron 11 of SLC7A9, respectively. This study identifies the first SLC7A9 variants causing feline cystinuria and reveals that, as in humans and dogs, this disease is genetically heterogeneous in cats.

Glucose transporter-1 deficiency syndrome : the expanding clinical and genetic spectrum of a treatable disorder

NARCIS (Netherlands)

Leen, Wilhelmina G.; Klepper, Joerg; Verbeek, Marcel M.; Leferink, Maike; Hofste, Tom; van Engelen, Baziel G.; Wevers, Ron A.; Arthur, Todd; Bahi-Buisson, Nadia; Ballhausen, Diana; Bekhof, Jolita; van Bogaert, Patrick; Carrilho, Ines; Chabrol, Brigitte; Champion, Michael P.; Coldwell, James; Clayton, Peter; Donner, Elizabeth; Evangeliou, Athanasios; Ebinger, Friedrich; Farrell, Kevin; Forsyth, Rob J.; de Goede, Christian G. E. L.; Gross, Stephanie; Grunewald, Stephanie; Holthausen, Hans; Jayawant, Sandeep; Lachlan, Katherine; Laugel, Vincent; Leppig, Kathy; Lim, Ming J.; Mancini, Grazia; Della Marina, Adela; Martorell, Loreto; McMenamin, Joe; Meuwissen, Marije E. C.; Mundy, Helen; Nilsson, Nils O.; Panzer, Axel; Poll-The, Bwee T.; Rauscher, Christian; Rouselle, Christophe M. R.; Sandvig, Inger; Scheffner, Thomas; Sheridan, Eamonn; Simpson, Neil; Sykora, Parol; Tomlinson, Richard; Trounce, John; Webb, David; Weschke, Bernhard; Scheffer, Hans; Willemsen, Michel A.

Glucose transporter-1 deficiency syndrome is caused by mutations in the SLC2A1 gene in the majority of patients and results in impaired glucose transport into the brain. From 2004-2008, 132 requests for mutational analysis of the SLC2A1 gene were studied by automated Sanger sequencing and multiplex

Glucose transporter-1 deficiency syndrome: The expanding clinical and genetic spectrum of a treatable disorder

NARCIS (Netherlands)

W.G. Leen (Wilhelmina); J. Klepper (Joerg); M.M. Verbeek (Marcel); M. Leferink (Maike); T. Hofste (Tom); B.G.M. van Engelen (Baziel); R.A. Wevers (Ron); T. Arthur (Todd); N. Bahi-Buisson (Nadia); D. Ballhausen (Diana); J. Bekhof (Jolita); P. van Bogaert (Patrick); I. Carrilho (Inês); B. Chabrol (Brigitte); M.P. Champion (Michael); J. Coldwell (James); P. Clayton (Peter); E. Donner (Elizabeth); A. Evangeliou (Athanasios); F. Ebinger (Friedrich); K. Farrell (Kevin); R.J. Forsyth (Rob); C.G.E.L. de Goede (Christian); S. Gross (Stephanie); S. Grünewald (Sonja); H. Holthausen (Hans); S. Jayawant (Sandeep); K. Lachlan (Katherine); V. Laugel (Vincent); K. Leppig (Kathy); M.J. Lim (Ming); G.M.S. Mancini (Grazia); A.D. Marina; L. Martorell (Loreto); J. McMenamin (Joe); M.E.C. Meuwissen (Marije); H. Mundy (Helen); N.O. Nilsson (Nils); A. Panzer (Axel); B.T. Poll-The; C. Rauscher (Christian); C.M.R. Rouselle (Christophe); I. Sandvig (Inger); T. Scheffner (Thomas); E. Sheridan (Eamonn); N. Simpson (Neil); P. Sykora (Parol); R. Tomlinson (Richard); J. Trounce (John); D.W.M. Webb (David); B. Weschke (Bernhard); H. Scheffer (Hans); M.A. Willemsen (Michél)

2010-01-01

textabstractGlucose transporter-1 deficiency syndrome is caused by mutations in the SLC2A1 gene in the majority of patients and results in impaired glucose transport into the brain. From 2004-2008, 132 requests for mutational analysis of the SLC2A1 gene were studied by automated Sanger sequencing

Glucose transporter-1 deficiency syndrome: the expanding clinical and genetic spectrum of a treatable disorder

NARCIS (Netherlands)

Leen, Wilhelmina G.; Klepper, Joerg; Verbeek, Marcel M.; Leferink, Maike; Hofste, Tom; van Engelen, Baziel G.; Wevers, Ron A.; Arthur, Todd; Bahi-Buisson, Nadia; Ballhausen, Diana; Bekhof, Jolita; van Bogaert, Patrick; Carrilho, Inês; Chabrol, Brigitte; Champion, Michael P.; Coldwell, James; Clayton, Peter; Donner, Elizabeth; Evangeliou, Athanasios; Ebinger, Friedrich; Farrell, Kevin; Forsyth, Rob J.; de Goede, Christian G. E. L.; Gross, Stephanie; Grunewald, Stephanie; Holthausen, Hans; Jayawant, Sandeep; Lachlan, Katherine; Laugel, Vincent; Leppig, Kathy; Lim, Ming J.; Mancini, Grazia; Marina, Adela Della; Martorell, Loreto; McMenamin, Joe; Meuwissen, Marije E. C.; Mundy, Helen; Nilsson, Nils O.; Panzer, Axel; Poll-The, Bwee T.; Rauscher, Christian; Rouselle, Christophe M. R.; Sandvig, Inger; Scheffner, Thomas; Sheridan, Eamonn; Simpson, Neil; Sykora, Parol; Tomlinson, Richard; Trounce, John; Webb, David; Weschke, Bernhard; Scheffer, Hans; Willemsen, Michél A.

2010-01-01

Glucose transporter-1 deficiency syndrome is caused by mutations in the SLC2A1 gene in the majority of patients and results in impaired glucose transport into the brain. From 2004-2008, 132 requests for mutational analysis of the SLC2A1 gene were studied by automated Sanger sequencing and multiplex

Glucose transporter-1 deficiency syndrome: the expanding clinical and genetic spectrum of a treatable disorder.

NARCIS (Netherlands)

Leen, W.G.; Klepper, J.; Verbeek, M.M.; Leferink, M.; Hofste, T.; Engelen, B.G.M. van; Wevers, R.A.; Arthur, T.; Bahi-Buisson, N.; Ballhausen, D.; Bekhof, J.; Bogaert, P. van; Carrilho, I.; Chabrol, B.; Champion, M.P.; Coldwell, J.; Clayton, P.; Donner, E.; Evangeliou, A.; Ebinger, F.; Farrell, K.; Forsyth, R.J.; Goede, C.G. de; Gross, S.; Grunewald, S.; Holthausen, H.; Jayawant, S.; Lachlan, K.; Laugel, V.; Leppig, K.; Lim, M.J.; Mancini, G.; Marina, A.D.; Martorell, L.; McMenamin, J.; Meuwissen, M.E.; Mundy, H.; Nilsson, N.O.; Panzer, A.; Poll-The, B.T.; Rauscher, C.; Rouselle, C.M.; Sandvig, I.; Scheffner, T.; Sheridan, E.; Simpson, N.; Sykora, P.; Tomlinson, R.; Trounce, J.; Webb, D.; Weschke, B.; Scheffer, H.; Willemsen, M.A.A.P.

2010-01-01

Glucose transporter-1 deficiency syndrome is caused by mutations in the SLC2A1 gene in the majority of patients and results in impaired glucose transport into the brain. From 2004-2008, 132 requests for mutational analysis of the SLC2A1 gene were studied by automated Sanger sequencing and multiplex

SLC25 Family Member Genetic Interactions Identify a Role for HEM25 in Yeast Electron Transport Chain Stability.

Science.gov (United States)

Dufay, J Noelia; Fernández-Murray, J Pedro; McMaster, Christopher R

2017-06-07

The SLC25 family member SLC25A38 (Hem25 in yeast) was recently identified as a mitochondrial glycine transporter that provides substrate to initiate heme/hemoglobin synthesis. Mutations in the human SLC25A38 gene cause congenital sideroblastic anemia. The full extent to which SLC25 family members coregulate heme synthesis with other mitochondrial functions is not clear. In this study, we surveyed 29 nonessential SLC25 family members in Saccharomyces cerevisiae for their ability to support growth in the presence and absence of HEM25 Six SLC25 family members were identified that were required for growth or for heme synthesis in cells lacking Hem25 function. Importantly, we determined that loss of function of the SLC25 family member Flx1, which imports FAD into mitochondria, together with loss of function of Hem25, resulted in inability to grow on media that required yeast cells to supply energy using mitochondrial respiration. We report that specific components of complexes of the electron transport chain are decreased in the absence of Flx1 and Hem25 function. In addition, we show that mitochondria from flx1 Δ hem25 Δ cells contain uncharacterized Cox2-containing high molecular weight aggregates. The functions of Flx1 and Hem25 provide a facile explanation for the decrease in heme level, and in specific electron transport chain complex components. Copyright © 2017 Dufay et al.

SLC25 Family Member Genetic Interactions Identify a Role for HEM25 in Yeast Electron Transport Chain Stability

Directory of Open Access Journals (Sweden)

J. Noelia Dufay

2017-06-01

Full Text Available The SLC25 family member SLC25A38 (Hem25 in yeast was recently identified as a mitochondrial glycine transporter that provides substrate to initiate heme/hemoglobin synthesis. Mutations in the human SLC25A38 gene cause congenital sideroblastic anemia. The full extent to which SLC25 family members coregulate heme synthesis with other mitochondrial functions is not clear. In this study, we surveyed 29 nonessential SLC25 family members in Saccharomyces cerevisiae for their ability to support growth in the presence and absence of HEM25. Six SLC25 family members were identified that were required for growth or for heme synthesis in cells lacking Hem25 function. Importantly, we determined that loss of function of the SLC25 family member Flx1, which imports FAD into mitochondria, together with loss of function of Hem25, resulted in inability to grow on media that required yeast cells to supply energy using mitochondrial respiration. We report that specific components of complexes of the electron transport chain are decreased in the absence of Flx1 and Hem25 function. In addition, we show that mitochondria from flx1Δ hem25Δ cells contain uncharacterized Cox2-containing high molecular weight aggregates. The functions of Flx1 and Hem25 provide a facile explanation for the decrease in heme level, and in specific electron transport chain complex components.

Neurosteroid Transport in the Brain: Role of ABC and SLC Transporters

Directory of Open Access Journals (Sweden)

Markus Grube

2018-04-01

Full Text Available Neurosteroids, comprising pregnane, androstane, and sulfated steroids can alter neuronal excitability through interaction with ligand-gated ion channels and other receptors and have therefore a therapeutic potential in several brain disorders. They can be formed in brain cells or are synthesized by an endocrine gland and reach the brain by penetrating the blood–brain barrier (BBB. Especially sulfated steroids such as pregnenolone sulfate (PregS and dehydroepiandrosterone sulfate (DHEAS depend on transporter proteins to cross membranes. In this review, we discuss the involvement of ATP-binding cassette (ABC- and solute carrier (SLC-type membrane proteins in the transport of these compounds at the BBB and in the choroid plexus (CP, but also in the secretion from neurons and glial cells. Among the ABC transporters, especially BCRP (ABCG2 and several MRP/ABCC subfamily members (MRP1, MRP4, MRP8 are expressed in the brain and known to efflux conjugated steroids. Furthermore, several SLC transporters have been shown to mediate cellular uptake of steroid sulfates. These include members of the OATP/SLCO subfamily, namely OATP1A2 and OATP2B1, as well as OAT3 (SLC22A3, which have been reported to be expressed at the BBB, in the CP and in part in neurons. Furthermore, a role of the organic solute transporter OSTα-OSTβ (SLC51A/B in brain DHEAS/PregS homeostasis has been proposed. This transporter was reported to be localized especially in steroidogenic cells of the cerebellum and hippocampus. To date, the impact of transporters on neurosteroid homeostasis is still poorly understood. Further insights are desirable also with regard to the therapeutic potential of these compounds.

Hypoxic Stress Upregulates the Expression of Slc38a1 in Brown Adipocytes via Hypoxia-Inducible Factor-1α.

Science.gov (United States)

Horie, Tetsuhiro; Fukasawa, Kazuya; Iezaki, Takashi; Park, Gyujin; Onishi, Yuki; Ozaki, Kakeru; Kanayama, Takashi; Hiraiwa, Manami; Kitaguchi, Yuka; Kaneda, Katsuyuki; Hinoi, Eiichi

2018-01-01

The availability of amino acid in the brown adipose tissue (BAT) has been shown to be altered under various conditions; however, little is known about the possible expression and pivotal role of amino acid transporters in BAT under physiological and pathological conditions. The present study comprehensively investigated whether amino acid transporters are regulated by obesogenic conditions in BAT in vivo. Moreover, we investigated the mechanism underlying the regulation of the expression of amino acid transporters by various stressors in brown adipocytes in vitro. The expression of solute carrier family 38 member 1 (Slc38a1; gene encoding sodium-coupled neutral amino acid transporter 1) was preferentially upregulated in the BAT of both genetic and acquired obesity mice in vivo. Moreover, the expression of Slc38a1 was induced by hypoxic stress through hypoxia-inducible factor-1α, which is a master transcription factor of the adaptive response to hypoxic stress, in brown adipocytes in vitro. These results indicate that Slc38a1 is an obesity-associated gene in BAT and a hypoxia-responsive gene in brown adipocytes. © 2017 S. Karger AG, Basel.

Mutations in the GABA Transporter SLC6A1 Cause Epilepsy with Myoclonic-Atonic Seizures

DEFF Research Database (Denmark)

Carvill, Gemma L; McMahon, Jacinta M; Schneider, Amy

2015-01-01

GAT-1, encoded by SLC6A1, is one of the major gamma-aminobutyric acid (GABA) transporters in the brain and is responsible for re-uptake of GABA from the synapse. In this study, targeted resequencing of 644 individuals with epileptic encephalopathies led to the identification of six SLC6A1 mutatio...

SLC5A8 gene, a transporter of butyrate: a gut flora metabolite, is frequently methylated in African American colon adenomas.

Directory of Open Access Journals (Sweden)

Hassan Brim

Full Text Available Colon cancer is one of the leading causes of cancer related deaths. Its impact on African Americans (AAs is higher than in the general population both in the incidence and mortality from the disease. Colon cancer aggressiveness in AAs as well as non-frequent check-ups and follow up in this population have been proposed as ways to explain the observed discrepancies. These facts made the detection of early carcinogenesis markers in this population a priority.Here, we analyzed 50 colon adenomas from AA patients for both microsatellite instability (MSI and the methylation status of SLC5A8 gene. This gene's product is involved in the transport of butyrate that has anti-proliferative properties through its effects on histone acetylation and gene expression. A proteomic analysis to check the expressed histones in adenoma and normal tissues was also performed.The analyzed samples displayed 82% (n = 41 methylation level of SLC5A8 gene in adenomas. The MSI-H (high adenoma were about 18% (n = 9 while the rest were mostly MSS (microsatellite stable with few MSI-L (Low. No association was found between SLC5A8 methylation and the MSI status. Also, there was no association between SLC5A8 methylation and the sex and age of the patients. However, there were more right sided adenomas with SLC5A8 methylation than the left sided ones. The proteomic analysis revealed distinct histone expression profiles between normal and adenoma tissues.SLC5A8 is highly methylated in AA colon adenomas which points to its potential use as a marker for early detection. The MSI rate is similar to that found in colon cancer tumors in AAs. These findings suggest that both processes stem from the same epigenetic and genetic events occurring at an early stage in colon carcinogenesis in AAs.

Disruption of Slc52a3 gene causes neonatal lethality with riboflavin deficiency in mice

OpenAIRE

Yoshimatsu, Hiroki; Yonezawa, Atsushi; Yamanishi, Kaori; Yao, Yoshiaki; Sugano, Kumiko; Nakagawa, Shunsaku; Imai, Satoshi; Omura, Tomohiro; Nakagawa, Takayuki; Yano, Ikuko; Masuda, Satohiro; Inui, Ken-ichi; Matsubara, Kazuo

2016-01-01

Homeostasis of riboflavin should be maintained by transporters. Previous in vitro studies have elucidated basic information about riboflavin transporter RFVT3 encoded by SLC52A3 gene. However, the contribution of RFVT3 to the maintenance of riboflavin homeostasis and the significance in vivo remain unclear. Here, we investigated the physiological role of RFVT3 using Slc52a3 knockout (Slc52a3−/−) mice. Most Slc52a3−/− mice died with hyperlipidemia and hypoglycemia within 48 hr after birth. The...

SLC52A2 [p.P141T] and SLC52A3 [p.N21S] causing Brown-Vialetto-Van Laere Syndrome in an Indian patient: First genetically proven case with mutations in two riboflavin transporters.

Science.gov (United States)

Udhayabanu, Tamilarasan; Subramanian, Veedamali S; Teafatiller, Trevor; Gowda, Vykuntaraju K; Raghavan, Varun S; Varalakshmi, Perumal; Said, Hamid M; Ashokkumar, Balasubramaniem

2016-11-01

Brown-Vialetto-Van Laere Syndrome (BVVLS), a rare neurological disorder characterized by bulbar palsies and sensorineural deafness, is mainly associated with defective riboflavin transporters encoded by the SLC52A2 and SLC52A3 genes. Here we present a 16-year-old BVVLS patient belonging to a five generation consanguineous family from Indian ethnicity with two homozygous missense mutations viz., c.421C>A [p.P141T] in SLC52A2 and c.62A>G [p.N21S] in SLC52A3. Functional characterization based on 3 H-riboflavin uptake assay and live-cell confocal imaging revealed that the effect of mutation c.421C>A [p.P141T] identified in SLC52A2 had a slight reduction in riboflavin uptake; on the other hand, the c.62A>G [p.N21S] identified in SLC52A3 showed a drastic reduction in riboflavin uptake, which appeared to be due to impaired trafficking and membrane targeting of the hRFVT-3 protein. This is the first report presenting mutations in both riboflavin transporters hRFVT-2 and hRFVT-3 in the same BVVLS patient. Also, c.62A>G [p.N21S] in SLC52A3 appears to contribute more to the disease phenotype in this patient than c.421C>A [p.P141T] in SLC52A2. Copyright © 2016 Elsevier B.V. All rights reserved.

A partial gene deletion of SLC45A2 causes oculocutaneous albinism in Doberman pinscher dogs.

Directory of Open Access Journals (Sweden)

Paige A Winkler

Full Text Available The first white Doberman pinscher (WDP dog was registered by the American Kennel Club in 1976. The novelty of the white coat color resulted in extensive line breeding of this dog and her offspring. The WDP phenotype closely resembles human oculocutaneous albinism (OCA and clinicians noticed a seemingly high prevalence of pigmented masses on these dogs. This study had three specific aims: (1 produce a detailed description of the ocular phenotype of WDPs, (2 objectively determine if an increased prevalence of ocular and cutaneous melanocytic tumors was present in WDPs, and (3 determine if a genetic mutation in any of the genes known to cause human OCA is causal for the WDP phenotype. WDPs have a consistent ocular phenotype of photophobia, hypopigmented adnexal structures, blue irides with a tan periphery and hypopigmented retinal pigment epithelium and choroid. WDPs have a higher prevalence of cutaneous melanocytic neoplasms compared with control standard color Doberman pinschers (SDPs; cutaneous tumors were noted in 12/20 WDP (5 years of age: 8/8 and 1/20 SDPs (p<0.00001. Using exclusion analysis, four OCA causative genes were investigated for their association with WDP phenotype; TYR, OCA2, TYRP1 and SLC45A2. SLC45A2 was found to be linked to the phenotype and gene sequencing revealed a 4,081 base pair deletion resulting in loss of the terminus of exon seven of SLC45A2 (chr4∶77,062,968-77,067,051. This mutation is highly likely to be the cause of the WDP phenotype and is supported by a lack of detectable SLC45A2 transcript levels by reverse transcriptase PCR. The WDP provides a valuable model for studying OCA4 visual disturbances and melanocytic neoplasms in a large animal model.

SLC6A1 Mutation and Ketogenic Diet in Epilepsy With Myoclonic-Atonic Seizures.

Science.gov (United States)

Palmer, Samantha; Towne, Meghan C; Pearl, Phillip L; Pelletier, Renee C; Genetti, Casie A; Shi, Jiahai; Beggs, Alan H; Agrawal, Pankaj B; Brownstein, Catherine A

2016-11-01

Epilepsy with myoclonic-atonic seizures, also known as myoclonic-astatic epilepsy or Doose syndrome, has been recently linked to variants in the SLC6A1 gene. Epilepsy with myoclonic-atonic seizures is often refractory to antiepileptic drugs, and the ketogenic diet is known for treating medically intractable seizures, although the mechanism of action is largely unknown. We report a novel SLC6A1 variant in a patient with epilepsy with myoclonic-atonic seizures, analyze its effects, and suggest a mechanism of action for the ketogenic diet. We describe a ten-year-old girl with epilepsy with myoclonic-atonic seizures and a de novo SLC6A1 mutation who responded well to the ketogenic diet. She carried a c.491G>A mutation predicted to cause p.Cys164Tyr amino acid change, which was identified using whole exome sequencing and confirmed by Sanger sequencing. High-resolution structural modeling was used to analyze the likely effects of the mutation. The SLC6A1 gene encodes a transporter that removes gamma-aminobutyric acid from the synaptic cleft. Mutations in SLC6A1 are known to disrupt the gamma-aminobutyric acid transporter protein 1, affecting gamma-aminobutyric acid levels and causing seizures. The p.Cys164Tyr variant found in our study has not been previously reported, expanding on the variants linked to epilepsy with myoclonic-atonic seizures. A 10-year-old girl with a novel SLC6A1 mutation and epilepsy with myoclonic-atonic seizures had an excellent clinical response to the ketogenic diet. An effect of the diet on gamma-aminobutyric acid reuptake mediated by gamma-aminobutyric acid transporter protein 1 is suggested. A personalized approach to epilepsy with myoclonic-atonic seizures patients carrying SLC6A1 mutation and a relationship between epilepsy with myoclonic-atonic seizures due to SLC6A1 mutations, GABAergic drugs, and the ketogenic diet warrants further exploration. Copyright © 2016 Elsevier Inc. All rights reserved.

Mutations in the HFE, TFR2, and SLC40A1 genes in patients with hemochromatosis.

Science.gov (United States)

Del-Castillo-Rueda, Alejandro; Moreno-Carralero, María-Isabel; Cuadrado-Grande, Nuria; Alvarez-Sala-Walther, Luis-Antonio; Enríquez-de-Salamanca, Rafael; Méndez, Manuel; Morán-Jiménez, María-Josefa

2012-10-15

Hereditary hemochromatosis causes iron overload and is associated with a variety of genetic and phenotypic conditions. Early diagnosis is important so that effective treatment can be administered and the risk of tissue damage avoided. Most patients are homozygous for the c.845G>A (p.C282Y) mutation in the HFE gene; however, rare forms of genetic iron overload must be diagnosed using a specific genetic analysis. We studied the genotype of 5 patients who had hyperferritinemia and an iron overload phenotype, but not classic mutations in the HFE gene. Two patients were undergoing phlebotomy and had no iron overload, 1 with metabolic syndrome and no phlebotomy had mild iron overload, and 2 patients had severe iron overload despite phlebotomy. The patients' first-degree relatives also underwent the analysis. We found 5 not previously published mutations: c.-408_-406delCAA in HFE, c.1118G>A (p.G373D), c.1473G>A (p.E491E) and c.2085G>C (p.S695S) in TFR2; and c.-428_-427GG>TT in SLC40A1. Moreover, we found 3 previously published mutations: c.221C>T (p.R71X) in HFE; c.1127C>A (p.A376D) in TFR2; and c.539T>C (p.I180T) in SLC40A1. Four patients were double heterozygous or compound heterozygous for the mutations mentioned above, and the patient with metabolic syndrome was heterozygous for a mutation in the TFR2 gene. Our findings show that hereditary hemochromatosis is clinically and genetically heterogeneous and that acquired factors may modify or determine the phenotype. Copyright © 2012. Published by Elsevier B.V.

Inhibition of SLC1A5 sensitizes colorectal cancer to cetuximab.

Science.gov (United States)

Ma, Huanrong; Wu, Zhenzhen; Peng, Jianjun; Li, Yang; Huang, Hongxiang; Liao, Yi; Zhou, Minyu; Sun, Li; Huang, Na; Shi, Min; Bin, Jianping; Liao, Yulin; Rao, Jinjun; Wang, Lin; Liao, Wangjun

2018-06-15

Cetuximab resistance is a key barrier in treating metastatic colorectal cancer (mCRC). Targeting of metabolic resources import could resensitize drug-resistant cancer cells to anticancer treatments. Here we showed that the expression of the glutamine transporter solute carrier 1 family member 5 (SLC1A5) in clinical CRC samples of patients resisted to cetuximab was significantly higher than in those of patients responded to cetuximab. Inhibition of SLC1A5 by shRNA-mediated gene silencing or pharmacological inhibitor significantly suppressed the growth of CRC. Moreover, inhibition of SLC1A5 significantly enhanced the inhibitory efficacy of cetuximab on CRC proliferation both in vitro and in vivo. Mechanistically, SLC1A5 inhibition facilitated EGFR degradation through the ubiquitin-proteasome pathway, and decreased the expression of nuclear EGFR, both of which might have contribution to the improved response to cetuximab. This study provides the metabolic molecule SLC1A5 as a potential therapeutic target to increase the efficacy of cetuximab on CRC. © 2018 UICC.

Study of the serotonin transporter (SLC6A4 and BDNF genes in French patients with non syndromic mental deficiency

Directory of Open Access Journals (Sweden)

Mignon Laurence

2010-02-01

Full Text Available Abstract Background Mental deficiency has been linked to abnormalities in cortical neuronal network connectivity and plasticity. These mechanisms are in part under the control of two interacting signalling pathways, the serotonergic and the brain-derived neurotrophic (BDNF pathways. The aim of the current paper is to determine whether particular alleles or genotypes of two crucial genes of these systems, the serotonin transporter gene (SLC6A4 and the brain-derived neurotrophic factor gene (BDNF, are associated with mental deficiency (MD. Methods We analyzed four functional polymorphisms (rs25531, 5-HTTLPR, VNTR, rs3813034 of the SLC6A4 gene and one functional polymorphism (Val66 Met of the BDNF gene in 98 patients with non-syndromic mental deficiency (NS-MD and in an ethnically matched control population of 251 individuals. Results We found no significant differences in allele and genotype frequencies in the five polymorphisms studied in the SLC6A4 and BDNF genes of NS-MD patients versus control patients. While the comparison of the patterns of linkage disequilibrium (D' in the control and NS-MD populations revealed a degree of variability it did not, however, reach significance. No significant differences in frequencies of haplotypes and genotypes for VNTR/rs3813034 and rs25531/5-HTTLPR were observed. Conclusion Altogether, results from the present study do not support a role for any of the five functional polymorphisms of SLC6A4 and BDNF genes in the aetiology of NS-RM. Moreover, they suggest no epistatic interaction in NS-MD between polymorphisms in BDNF and SLC6A4. However, we suggest that further studies on these two pathways in NS-MD remain necessary.

SLC6 Neurotransmitter Transporters: Structure, Function, and Regulation

DEFF Research Database (Denmark)

Kristensen, Anders S; Andersen, Jacob; Jørgensen, Trine N

2011-01-01

The neurotransmitter transporters (NTTs) belonging to the solute carrier 6 (SLC6) gene family (also referred to as the neurotransmitter-sodium-symporter family or Na(+)/Cl(-)-dependent transporters) comprise a group of nine sodium- and chloride-dependent plasma membrane transporters...... for the monoamine neurotransmitters serotonin (5-hydroxytryptamine), dopamine, and norepinephrine, and the amino acid neurotransmitters GABA and glycine. The SLC6 NTTs are widely expressed in the mammalian brain and play an essential role in regulating neurotransmitter signaling and homeostasis by mediating uptake...... of released neurotransmitters from the extracellular space into neurons and glial cells. The transporters are targets for a wide range of therapeutic drugs used in treatment of psychiatric diseases, including major depression, anxiety disorders, attention deficit hyperactivity disorder and epilepsy...

Partial deletion of the sulfate transporter SLC13A1 is associated with an osteochondrodysplasia in the Miniature Poodle breed.

Directory of Open Access Journals (Sweden)

Mark W Neff

Full Text Available A crippling dwarfism was first described in the Miniature Poodle in Great Britain in 1956. Here, we resolve the genetic basis of this recessively inherited disorder. A case-control analysis (8:8 of genotype data from 173 k SNPs revealed a single associated locus on CFA14 (P(raw <10(-8. All affected dogs were homozygous for an ancestral haplotype consistent with a founder effect and an identical-by-descent mutation. Systematic failure of nine, nearly contiguous SNPs, was observed solely in affected dogs, suggesting a deletion was the causal mutation. A 130-kb deletion was confirmed both by fluorescence in situ hybridization (FISH analysis and by cloning the physical breakpoints. The mutation was perfectly associated in all cases and obligate heterozygotes. The deletion ablated all but the first exon of SLC13A1, a sodium/sulfate symporter responsible for regulating serum levels of inorganic sulfate. Our results corroborate earlier findings from an Slc13a1 mouse knockout, which resulted in hyposulfatemia and syndromic defects. Interestingly, the metabolic disorder in Miniature Poodles appears to share more clinical signs with a spectrum of human disorders caused by SLC26A2 than with the mouse Slc13a1 model. SLC26A2 is the primary sodium-independent sulfate transporter in cartilage and bone and is important for the sulfation of proteoglycans such as aggregan. We propose that disruption of SLC13A1 in the dog similarly causes undersulfation of proteoglycans in the extracellular matrix (ECM, which impacts the conversion of cartilage to bone. A co-dominant DNA test of the deletion was developed to enable breeders to avoid producing affected dogs and to selectively eliminate the mutation from the gene pool.

[Polymorphism in the Serotonin Transporter Gene (SLC6A4) and Emotional Bipolar Disorder in Two Regional Mental Health Centers from the Eje Cafetero (Colombia)].

Science.gov (United States)

Ramos, Lucero Rengifo; Arias, Duverney Gaviria; Salazar, Liliana Salazar; Vélez, Juan Pablo; Pardo, Stella Lozano

2012-03-01

The indel polymorphisms in the promoting region and the 2(nd) intron polymorphisms in the serotonin transporter gene (SLC6A4) have been associated to bipolar disorder 1 (BD1) in several population studies. The objective was to analyze the genotypic and allelic frequencies in both gene regions in a study of cases and controls with individuals from Risaralda and Quindío (Colombia) so as to establish possible associations to BD1, and compare results with previous and similar studies. 133 patients and 120 controls were studied. L and S indel polymorphisms in the promoting region were analyzed by PCR, together with VNTR STin2.10 and STin 2.12 VNTRs polymorphisms in the 2(nd) intron of the SL-C6A4 gene Genotypic and allelic frequencies for the S and L polymorphisms were similar both in cases and controls. However, the LL genotype was significantly increased both in BD1 population (OR=1.89; CI95%=1.1-3.68), and when discriminated by gender. This particular genotype in general population is OR=2.22; IC95%=1.04-5.66 for women, and OR=1.62; IC 95%=0.71-4.39 for men. No significant genotypic and allelic differences were found for VNTR STin2.10 and STin 2.12. polymorphisms. No association was found between polymorphisms of 5-HTTLPR polymorphisms and the 2(nd) intron of the serotonin transporting gene in general patients with BD1, nor when compared by gender. Our results are similar to those reported for Caucasian populations and differ from those of Asian and Brazilian populations. Copyright © 2012 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

PCFT/SLC46A1 promoter methylation and restoration of gene expression in human leukemia cells

International Nuclear Information System (INIS)

Gonen, Nitzan; Bram, Eran E.; Assaraf, Yehuda G.

2008-01-01

The proton-coupled folate transporter (PCFT/SLC46A1) displays optimal and prominent folate and antifolate transport activity at acidic pH in human carcinoma cells but poor activity in leukemia cells. Consistently herein, human leukemia cell lines expressed poor PCFT transcript levels, whereas various carcinoma cell lines showed substantial PCFT gene expression. We identified a CpG island with high density at nucleotides -200 through +100 and explored its role in PCFT promoter silencing. Leukemia cells with barely detectable PCFT transcripts consistently harbored 85-100% methylation of this CpG island, whereas no methylation was found in carcinoma cells. Treatment with 5-Aza-2'-deoxycytidine which induced demethylation but not with the histone deacetylase inhibitor trichostatin A, restored 50-fold PCFT expression only in leukemia cells. These findings constitute the first demonstration of the dominant epigenetic silencing of the PCFT gene in leukemia cells. The potential translational implications of the restoration of PCFT expression in chemotherapy of leukemia are discussed

A Study of Single Nucleotide Polymorphisms of the SLC19A1/RFC1 Gene in Subjects with Autism Spectrum Disorder

Directory of Open Access Journals (Sweden)

Naila Al Mahmuda

2016-05-01

Full Text Available Autism Spectrum Disorder (ASD is a group of neurodevelopmental disorders with complex genetic etiology. Recent studies have indicated that children with ASD may have altered folate or methionine metabolism, suggesting that the folate–methionine cycle may play a key role in the etiology of ASD. SLC19A1, also referred to as reduced folate carrier 1 (RFC1, is a member of the solute carrier group of transporters and is one of the key enzymes in the folate metabolism pathway. Findings from multiple genomic screens suggest the presence of an autism susceptibility locus on chromosome 21q22.3, which includes SLC19A1. Therefore, we performed a case-control study in a Japanese population. In this study, DNA samples obtained from 147 ASD patients at the Kanazawa University Hospital in Japan and 150 unrelated healthy Japanese volunteers were examined by the sequence-specific primer-polymerase chain reaction method pooled with fluorescence correlation spectroscopy. p < 0.05 was considered to represent a statistically significant outcome. Of 13 single nucleotide polymorphisms (SNPs examined, a significant p-value was obtained for AA genotype of one SNP (rs1023159, OR = 0.39, 95% CI = 0.16–0.91, p = 0.0394; Fisher’s exact test. Despite some conflicting results, our findings supported a role for the polymorphism rs1023159 of the SLC19A1 gene, alone or in combination, as a risk factor for ASD. However, the findings were not consistent after multiple testing corrections. In conclusion, although our results supported a role of the SLC19A1 gene in the etiology of ASD, it was not a significant risk factor for the ASD samples analyzed in this study.

Structure of Bor1 supports an elevator transport mechanism for SLC4 anion exchangers.

Science.gov (United States)

Thurtle-Schmidt, Bryan H; Stroud, Robert M

2016-09-20

Boron is essential for plant growth because of its incorporation into plant cell walls; however, in excess it is toxic to plants. Boron transport and homeostasis in plants is regulated in part by the borate efflux transporter Bor1, a member of the solute carrier (SLC) 4 transporter family with homology to the human bicarbonate transporter Band 3. Here, we present the 4.1-Å resolution crystal structure of Arabidopsis thaliana Bor1. The structure displays a dimeric architecture in which dimerization is mediated by centralized Gate domains. Comparisons with a structure of Band 3 in an outward-open state reveal that the Core domains of Bor1 have rotated inwards to achieve an occluded state. Further structural comparisons with UapA, a xanthine transporter from the nucleobase-ascorbate transporter family, show that the downward pivoting of the Core domains relative to the Gate domains may access an inward-open state. These results suggest that the SLC4, SLC26, and nucleobase-ascorbate transporter families all share an elevator transport mechanism in which alternating access is provided by Core domains that carry substrates across a membrane.

Association between a genetic variant in the serotonin transporter gene (SLC6A4) and suicidal behavior in patients with schizophrenia

DEFF Research Database (Denmark)

Lindholm Carlstrom, Eva; Saetre, Peter; Rosengren, Anders

2012-01-01

ABSTRACT: BACKGROUND: The serotonin (5-hydroxytryptamin; 5-HT) system has a central role in the circuitry of cognition and emotions. Multiple lines of evidence suggest that genetic variation in the serotonin transporter gene (SLC6A4; 5-HTT) is associated with schizophrenia and suicidal behavior. ...

Amino acid derivatives are substrates or non-transported inhibitors of the amino acid transporter PAT2 (slc36a2).

Science.gov (United States)

Edwards, Noel; Anderson, Catriona M H; Gatfield, Kelly M; Jevons, Mark P; Ganapathy, Vadivel; Thwaites, David T

2011-01-01

The H(+)-coupled amino acid transporter PAT2 (SLC36A2) transports the amino acids proline, glycine, alanine and hydroxyproline. A physiological role played by PAT2 in amino acid reabsorption in the renal proximal tubule is demonstrated by mutations in SLC36A2 that lead to an iminoglycinuric phenotype (imino acid and glycine uria) in humans. A number of proline, GABA and tryptophan derivatives were examined to determine if they function either as transported substrates or non-transported inhibitors of PAT2. The compounds were investigated following heterologous expression of rat PAT2 in Xenopus laevis oocytes. PAT2 function was characterised by: radiotracer uptake and competition (cis-inhibition) studies; radiotracer efflux and trans-stimulation; and measurement of substrate-induced positive inward current by two-electrode voltage-clamp. In general, the proline derivatives appeared to be transported substrates and the relative ability to induce current flow was closely related to the inhibitory effects on PAT2-mediated l-[(3)H]proline uptake. In contrast, certain heterocyclic GABA derivatives (e.g. l-pipecolic acid) were translocated only slowly. Finally, the tryptophan derivatives inhibited PAT2 function but did not undergo transport. l-Proline uptake was inhibited by 5-hydroxy-l-tryptophan (IC(50) 1.6±0.4mM), α-methyl-d,l-tryptophan (3.5±1.5mM), l-tryptophan, 1-methyl-l-tryptophan and indole-3-propionic acid. Although neither 5-hydroxy-l-tryptophan nor α-methyl-d,l-tryptophan were able to elicit inward current in PAT2-expressing oocytes both reduced the current evoked by l-proline. 5-Hydroxy-l-tryptophan and α-methyl-d,l-tryptophan were unable to trans-stimulate l-proline efflux from PAT2-expressing oocytes, confirming that the two compounds act as non-transported blockers of PAT2. These two tryptophan derivatives should prove valuable experimental tools in future investigations of the physiological roles of PAT2. Copyright © 2010 Elsevier B.V. All rights

Genetic variation of the GLUT10 glucose transporter (SLC2A10) and relationships to type 2 diabetes and intermediary traits

DEFF Research Database (Denmark)

Andersen, Gitte; Rose, Christian Schack; Hamid, Yasmin Hassan

2003-01-01

The SLC2A10 gene encodes the GLUT10 facilitative glucose transporter, which is expressed in high amounts in liver and pancreas. The gene is mapped to chromosome 20q12-q13.1, a region that has been shown to be linked to type 2 diabetes. The gene was examined in 61 Danish type 2 diabetic patients......, and a total of six variants (-27C-->T, Ala206Thr, Ala272Ala, IVS2 + 10G-->A, IVS4 + 18T-->G, and IVS4 + 26G-->A) were identified and investigated in an association study, which included 503 type 2 diabetic patients and 510 glucose-tolerant control subjects. None of the variants were associated with type 2...... substantially to the pathogenesis of type 2 diabetes in the examined study population. However, the codon 206 polymorphism may be related to the interindividual variation in fasting and oral glucose-induced serum insulin levels....

Upregulation of the Creatine Transporter Slc6A8 by Klotho

Directory of Open Access Journals (Sweden)

Ahmad Almilaji

2014-11-01

Full Text Available Background/Aims: The transmembrane Klotho protein contributes to inhibition of 1,25(OH2D3 formation. The extracellular domain of Klotho protein could function as an enzyme with e.g. β-glucuronidase activity, be cleaved off and be released into blood and cerebrospinal fluid. Klotho regulates several cellular transporters. Klotho protein deficiency accelerates the appearance of age related disorders including neurodegeneration and muscle wasting and eventually leads to premature death. The main site of Klotho protein expression is the kidney. Klotho protein is also appreciably expressed in other tissues including chorioid plexus. The present study explored the effect of Klotho protein on the creatine transporter CreaT (Slc6A8, which participates in the maintenance of neuronal function and survival. Methods: To this end cRNA encoding Slc6A8 was injected into Xenopus oocytes with and without additional injection of cRNA encoding Klotho protein. Creatine transporter CreaT (Slc6A8 activity was estimated from creatine induced current determined by two-electrode voltage-clamp. Results: Coexpression of Klotho protein significantly increased creatine-induced current in Slc6A8 expressing Xenopus oocytes. Coexpression of Klotho protein delayed the decline of creatine induced current following inhibition of carrier insertion into the cell membrane by brefeldin A (5 µM. The increase of creatine induced current by coexpression of Klotho protein in Slc6A8 expressing Xenopus oocytes was reversed by β-glucuronidase inhibitor (DSAL. Similarly, treatment of Slc6A8 expressing Xenopus oocytes with recombinant human alpha Klotho protein significantly increased creatine induced current. Conclusion: Klotho protein up-regulates the activity of creatine transporter CreaT (Slc6A8 by stabilizing the carrier protein in the cell membrane, an effect requiring β-glucuronidase activity of Klotho protein.

Association between SLC2A9 (GLUT9) gene polymorphisms and gout susceptibility: an updated meta-analysis.

Science.gov (United States)

Zhang, Xu; Yang, Xiao; Wang, Mengmeng; Li, Xiaona; Xia, Qing; Xu, Shengqian; Xu, Jianhua; Cai, Guoqi; Wang, Li; Xin, Lihong; Zou, Yanfeng; Pan, Faming

2016-08-01

The relationship between the SLC2A9 (solute carrier family 2, member 9) gene polymorphisms and gout was still inconsistent among the individual genetic association studies. Therefore, this present research was aimed to systematically evaluate the association between SLC2A9 gene polymorphisms and gout susceptibility. Relevant studies were enrolled by searching databases systematically. The pooled odds ratios (ORs) with 95 % confidence intervals (CIs) were used to assess the associations. The heterogeneity between each of the studies was calculated by using the Q statistic methods, and Begg's funnel plot and Egger's tests were performed to evaluate publication bias. A total of 13 studies investigated four single nucleotide polymorphisms (SNPs) in SLC2A9 were included. In this study, we found that the allele C of rs3733591 was higher in patients than in controls in both all-pooled population [C vs. T: OR (95 % CI) = 1.432 (1.213-1.691)] and Asians-pooled population [C vs. T: OR (95 % CI) = 1.583 (1.365-1.835)]. The allele frequency C of s6449213 was lower in the gout patients than in controls in both all-pooled population and Caucasians-pooled population. Additionally, the allele frequency T of rs16890979 and the allele frequency C of rs1014290 were lower in gout patients than in controls. This study demonstrated that the genetic susceptibility for gout is associated with the SLC2A9 gene polymorphisms. Four of them except for the rs3733591 are protective SNPs in Caucasians, and rs16890979 and rs1014290 are protective SNPs in both Caucasians and Asians, while rs3733591 may be susceptibility SNP in Asians.

Lack of Association between SLC30A8 Variants and Type 2 Diabetes in Mexican American Families

Directory of Open Access Journals (Sweden)

Hemant Kulkarni

2016-01-01

Full Text Available SLC30A8 encodes zinc transporter 8 which is involved in packaging and release of insulin. Evidence for the association of SLC30A8 variants with type 2 diabetes (T2D is inconclusive. We interrogated single nucleotide polymorphisms (SNPs around SLC30A8 for association with T2D in high-risk, pedigreed individuals from extended Mexican American families. This study of 118 SNPs within 50 kb of the SLC30A8 locus tested the association with eight T2D-related traits at four levels: (i each SNP using measured genotype approach (MGA; (ii interaction of SNPs with age and sex; (iii combinations of SNPs using Bayesian Quantitative Trait Nucleotide (BQTN analyses; and (iv entire gene locus using the gene burden test. Only one SNP (rs7817754 was significantly associated with incident T2D but a summary statistic based on all T2D-related traits identified 11 novel SNPs. Three SNPs and one SNP were weakly but interactively associated with age and sex, respectively. BQTN analyses could not demonstrate any informative combination of SNPs over MGA. Lastly, gene burden test results showed that at best the SLC30A8 locus could account for only 1-2% of the variability in T2D-related traits. Our results indicate a lack of association of the SLC30A8 SNPs with T2D in Mexican American families.

In silico analysis of consequences of non-synonymous SNPs of Slc11a2 gene in Indian bovines

Directory of Open Access Journals (Sweden)

Shreya M. Patel

2015-09-01

Full Text Available The aim of our study was to analyze the consequences of non-synonymous SNPs in Slc11a2 gene using bioinformatic tools. There is a current need of efficient bioinformatic tools for in-depth analysis of data generated by the next generation sequencing technologies. SNPs are known to play an imperative role in understanding the genetic basis of many genetic diseases. Slc11a2 is one of the major metal transporter families in mammals and plays a critical role in host defenses. In this study, we performed a comprehensive analysis of the impact of all non-synonymous SNPs in this gene using multiple tools like SIFT, PROVEAN, I-Mutant and PANTHER. Among the total 124 SNPs obtained from amplicon sequencing of Slc11a2 gene by Ion Torrent PGM involving 10 individuals of Gir cattle and Murrah buffalo each, we found 22 non-synonymous. Comparing the prediction of these 4 methods, 5 nsSNPs (G369R, Y374C, A377V, Q385H and N492S were identified as deleterious. In addition, while tested out for polar interactions with other amino acids in the protein, from above 5, Y374C, Q385H and N492S showed a change in interaction pattern and further confirmed by an increase in total energy after energy minimizations in case of mutant protein compared to the native.

Screening of SLC26A4, FOXI1, KCNJ10, and GJB2 in bilateral deafness patients with inner ear malformation.

Science.gov (United States)

Chen, Kaitian; Wang, Xianren; Sun, Liang; Jiang, Hongyan

2012-06-01

Bilateral nonsyndromic sensorineural hearing loss associated with inner ear malformation is closely related to genetics. SLC26A4 is considered to be the major involved gene. Recently, FOXI1 and KCNJ10 mutations have been linked to enlarged vestibular aqueducts and GJB2 mutations linked to temporal bone malformation. The authors aimed to investigate the mutation spectrums of these genes in Chinese patients with bilateral hearing impairment associated with inner ear malformation. Cross-sectional study. Affiliated hospital of the university. The authors analyzed the GJB2, SLC26A4, FOXI1, and KCNJ10 gene sequences in 43 patients presenting with bilateral hearing impairment associated with inner ear malformation using pyrosequencing and direct DNA sequencing. In total, 74.4% (32/43) of patients carried at least 1 of 14 pathogenic SLC26A4 mutations, including 6 novel mutations and 4 polymorphisms. Patients with enlarged vestibular aqueducts had a higher rate of SLC26A4 mutation than Mondini dysplasia patients. No FOXI1 or KCNJ10 potential pathogenic mutation was present, and GJB2 biallelic pathogenic mutations were uncommon (2.3%; 1/43). No significant correlation was observed between the genotype and phenotype of SLC26A4 mutations. SLC26A4 accounts for 74.4% of inner ear malformations in our cohort, whereas FOXI1, KCNJ10, and GJB2 mutations are not common. Other possible genes or external factors may contribute to this multibranch abnormality.

Activation of lysosomal P2X4 by ATP transported into lysosomes via VNUT/SLC17A9 using V‐ATPase generated voltage gradient as the driving force

Science.gov (United States)

Zhong, Xi Zoë; Cao, Qi; Sun, Xue

2016-01-01

Key points SLC17A9 proteins function as a lysosomal ATP transporter responsible for lysosomal ATP accumulation.P2X4 receptors act as lysosomal ion channels activated by luminal ATP.SLC17A9‐mediated ATP transport across the lysosomal membrane is suppressed by Bafilomycin A1, the V‐ATPase inhibitor.SLC17A9 mainly uses voltage gradient but not pH gradient generated by the V‐ATPase as the driving force to transport ATP into the lysosome to activate P2X4. Abstract The lysosome contains abundant ATP which plays important roles in lysosome functions and in cell signalling. Recently, solute carrier family 17 member 9 (SLC17A9, also known as VNUT for vesicular nucleotide transporter) proteins were suggested to function as a lysosomal ATP transporter responsible for lysosomal ATP accumulation, and P2X4 receptors were suggested to be lysosomal ion channels that are activated by luminal ATP. However, the molecular mechanism of SLC17A9 transporting ATP and the regulatory mechanism of lysosomal P2X4 are largely unknown. In this study, we report that SLC17A9‐mediated ATP transport across lysosomal membranes is suppressed by Bafilomycin A1, the V‐ATPase inhibitor. By measuring P2X4 activity, which is indicative of ATP transport across lysosomal membranes, we further demonstrated that SLC17A9 mainly uses voltage gradient but not pH gradient as the driving force to transport ATP into lysosomes. This study provides a molecular mechanism for lysosomal ATP transport mediated by SLC17A9. It also suggests a regulatory mechanism of lysosomal P2X4 by SLC17A9. PMID:27477609

The orphan transporter v7-3 (slc6a15) is a Na+-dependent neutral amino acid transporter (B0AT2)

DEFF Research Database (Denmark)

Bröer, Angelika; Tietze, Nadine; Kowalczuk, Sonja

2006-01-01

. The transporter is functionally and sequence related to B(0)AT1 (slc6a19) and was hence named B(0)AT2. Leucine, isoleucine, valine, proline and methionine were recognized by the transporter, with values of K(0.5) (half-saturation constant) ranging from 40 to 200 microM. Alanine, glutamine and phenylalanine were...

[The association of polymorphisms in SLC18A1, TPH1 and RELN genes with risk of paranoid schizophrenia].

Science.gov (United States)

Galaktionova, D Iu; Gareeva, A E; Khusnutdinova, E K; Nasedkina, T V

2014-01-01

We have developed a biochip for the analysis of polymorphisms in candidate genes for schizophrenia: DISC1, RELN, ZNF804A, PLXNA2, COMT, SLC18A41, CACNA1C, ANK3, TPH1, PLAA and SNAP-25. Using biochip the allele and genotype frequencies in 198 patients with schizophrenia and 192 healthy individuals have been obtained. For SLC18A1 polymorphism rs2270641 A>C, the frequencies of A allele (p = 0.007) and AA genotype (p = 0.002) were lower in patients compared with healthy individuals. A significant association was found between AA genotype (p = 0.036) of the TPH1 polymorphism rs1800532 C>A and schizophrenia. The C allele (p = 0.039) of the RELNpolymorphism rs7341475 C>T were lower in patients with schizophrenia compared with healthy individuals in a tatar population. Genotype AA of the TPH1 polymorphism rs1800532 C>A were more frequent in patients with schizophrenia compared with healthy individuals. Ithas been shown that the C allele (p = 0.0001) and GC (p = = 0.0001) genotype of the PLXNA2 polymorphism rs1327175 G>C are associated with the family history in patients with paranoid schizophrenia. The obtained data suggest that SLC18A1, TPH1 and RELN gene polymorphisms are associated with the risk of paranoid schizophrenia.

Association of a serotonin transporter gene (SLC6A4) 5-HTTLPR polymorphism with body mass index categories but not type 2 diabetes mellitus in Mexicans

Science.gov (United States)

Peralta-Leal, Valeria; Leal-Ugarte, Evelia; Meza-Espinoza, Juan P.; Dávalos-Rodríguez, Ingrid P.; Bocanegra-Alonso, Anabel; Acosta-González, Rosa I.; Gonzales, Enrique; Nair, Saraswathy; Durán-González, Jorge

2012-01-01

The serotonergic system has been hypothesized to contribute to the biological susceptibility to type 2 diabetes mellitus (T2DM) and body-mass index (BMI) categories. We investigate a possible association of 5-HTTLPR polymorphism (L and S alleles) in the promoter region of the serotonin transporter gene (SLC6A4) with the development of T2DM and/or higher BMI by analyzing a sample of 138 individuals diagnosed with T2DM and 172 unrelated controls from the Mexican general population. In the total sample genotypes were distributed according to Hardy-Weinberg equilibrium, and S allele frequency was 0.58. There was no statistical association between 5-HTTLPR polymorphism and the development of T2DM in this Mexican population sample (p = 0.12). Nevertheless, logistic regression analysis of the L allele and increased BMI disclosed an association, after adjusting for age, sex and T2DM (p = 0.02, OR 1.74, 95% CI: 1.079–2.808). PMID:23055796

Physiology of SLC12 transporters: lessons from inherited human genetic mutations and genetically engineered mouse knockouts.

Science.gov (United States)

Gagnon, Kenneth B; Delpire, Eric

2013-04-15

Among the over 300 members of the solute carrier (SLC) group of integral plasma membrane transport proteins are the nine electroneutral cation-chloride cotransporters belonging to the SLC12 gene family. Seven of these transporters have been functionally described as coupling the electrically silent movement of chloride with sodium and/or potassium. Although in silico analysis has identified two additional SLC12 family members, no physiological role has been ascribed to the proteins encoded by either the SLC12A8 or the SLC12A9 genes. Evolutionary conservation of this gene family from protists to humans confirms their importance. A wealth of physiological, immunohistochemical, and biochemical studies have revealed a great deal of information regarding the importance of this gene family to human health and disease. The sequencing of the human genome has provided investigators with the capability to link several human diseases with mutations in the genes encoding these plasma membrane proteins. The availability of bacterial artificial chromosomes, recombination engineering techniques, and the mouse genome sequence has simplified the creation of targeting constructs to manipulate the expression/function of these cation-chloride cotransporters in the mouse in an attempt to recapitulate some of these human pathologies. This review will summarize the three human disorders that have been linked to the mutation/dysfunction of the Na-Cl, Na-K-2Cl, and K-Cl cotransporters (i.e., Bartter's, Gitleman's, and Andermann's syndromes), examine some additional pathologies arising from genetically modified mouse models of these cotransporters including deafness, blood pressure, hyperexcitability, and epithelial transport deficit phenotypes.

The Role of Na:K:2Cl Cotransporter 1 (NKCC1/SLC12A2) in Dental Epithelium during Enamel Formation in Mice

Science.gov (United States)

Jalali, Rozita; Lodder, Johannes C.; Zandieh-Doulabi, Behrouz; Micha, Dimitra; Melvin, James E.; Catalan, Marcelo A.; Mansvelder, Huibert D.; DenBesten, Pamela; Bronckers, Antonius

2017-01-01

Na+:K+:2Cl− cotransporters (NKCCs) belong to the SLC12A family of cation-coupled Cl− transporters. We investigated whether enamel-producing mouse ameloblasts express NKCCs. Transcripts for Nkcc1 were identified in the mouse dental epithelium by RT-qPCR and NKCC1 protein was immunolocalized in outer enamel epithelium and in the papillary layer but not the ameloblast layer. In incisors of Nkcc1-null mice late maturation ameloblasts were disorganized, shorter and the mineral density of the enamel was reduced by 10% compared to wild-type controls. Protein levels of gap junction protein connexin 43, Na+-dependent bicarbonate cotransporter e1 (NBCe1), and the Cl−-dependent bicarbonate exchangers SLC26A3 and SLC26A6 were upregulated in Nkcc1-null enamel organs while the level of NCKX4/SLC24A4, the major K+, Na+ dependent Ca2+ transporter in maturation ameloblasts, was slightly downregulated. Whole-cell voltage clamp studies on rat ameloblast-like HAT-7 cells indicated that bumetanide increased ion-channel activity conducting outward currents. Bumetanide also reduced cell volume of HAT-7 cells. We concluded that non-ameloblast dental epithelium expresses NKCC1 to regulate cell volume in enamel organ and provide ameloblasts with Na+, K+ and Cl− ions required for the transport of mineral- and bicarbonate-ions into enamel. Absence of functional Nkcc1 likely is compensated by other types of ion channels and ion transporters. The increased amount of Cx43 in enamel organ cells in Nkcc1-null mice suggests that these cells display a higher number of gap junctions to increase intercellular communication. PMID:29209227

Complex analysis of urate transporters SLC2A9, SLC22A12 and functional characterization of non-synonymous allelic variants of GLUT9 in the Czech population: no evidence of effect on hyperuricemia and gout.

Science.gov (United States)

Hurba, Olha; Mancikova, Andrea; Krylov, Vladimir; Pavlikova, Marketa; Pavelka, Karel; Stibůrková, Blanka

2014-01-01

Using European descent Czech populations, we performed a study of SLC2A9 and SLC22A12 genes previously identified as being associated with serum uric acid concentrations and gout. This is the first study of the impact of non-synonymous allelic variants on the function of GLUT9 except for patients suffering from renal hypouricemia type 2. The cohort consisted of 250 individuals (150 controls, 54 nonspecific hyperuricemics and 46 primary gout and/or hyperuricemia subjects). We analyzed 13 exons of SLC2A9 (GLUT9 variant 1 and GLUT9 variant 2) and 10 exons of SLC22A12 by PCR amplification and sequenced directly. Allelic variants were prepared and their urate uptake and subcellular localization were studied by Xenopus oocytes expression system. The functional studies were analyzed using the non-parametric Wilcoxon and Kruskall-Wallis tests; the association study used the Fisher exact test and linear regression approach. We identified a total of 52 sequence variants (12 unpublished). Eight non-synonymous allelic variants were found only in SLC2A9: rs6820230, rs2276961, rs144196049, rs112404957, rs73225891, rs16890979, rs3733591 and rs2280205. None of these variants showed any significant difference in the expression of GLUT9 and in urate transport. In the association study, eight variants showed a possible association with hyperuricemia. However, seven of these were in introns and the one exon located variant, rs7932775, did not show a statistically significant association with serum uric acid concentration. Our results did not confirm any effect of SLC22A12 and SLC2A9 variants on serum uric acid concentration. Our complex approach using association analysis together with functional and immunohistochemical characterization of non-synonymous allelic variants did not show any influence on expression, subcellular localization and urate uptake of GLUT9.

A customized pigmentation SNP array identifies a novel SNP associated with melanoma predisposition in the SLC45A2 gene.

Directory of Open Access Journals (Sweden)

Maider Ibarrola-Villava

Full Text Available As the incidence of Malignant Melanoma (MM reflects an interaction between skin colour and UV exposure, variations in genes implicated in pigmentation and tanning response to UV may be associated with susceptibility to MM. In this study, 363 SNPs in 65 gene regions belonging to the pigmentation pathway have been successfully genotyped using a SNP array. Five hundred and ninety MM cases and 507 controls were analyzed in a discovery phase I. Ten candidate SNPs based on a p-value threshold of 0.01 were identified. Two of them, rs35414 (SLC45A2 and rs2069398 (SILV/CKD2, were statistically significant after conservative Bonferroni correction. The best six SNPs were further tested in an independent Spanish series (624 MM cases and 789 controls. A novel SNP located on the SLC45A2 gene (rs35414 was found to be significantly associated with melanoma in both phase I and phase II (P<0.0001. None of the other five SNPs were replicated in this second phase of the study. However, three SNPs in TYR, SILV/CDK2 and ADAMTS20 genes (rs17793678, rs2069398 and rs1510521 respectively had an overall p-value<0.05 when considering the whole DNA collection (1214 MM cases and 1296 controls. Both the SLC45A2 and the SILV/CDK2 variants behave as protective alleles, while the TYR and ADAMTS20 variants seem to function as risk alleles. Cumulative effects were detected when these four variants were considered together. Furthermore, individuals carrying two or more mutations in MC1R, a well-known low penetrance melanoma-predisposing gene, had a decreased MM risk if concurrently bearing the SLC45A2 protective variant. To our knowledge, this is the largest study on Spanish sporadic MM cases to date.

Deletion of the γ-Aminobutyric Acid Transporter 2 (GAT2 and SLC6A13) Gene in Mice Leads to Changes in Liver and Brain Taurine Contents*

Science.gov (United States)

Zhou, Yun; Holmseth, Silvia; Guo, Caiying; Hassel, Bjørnar; Höfner, Georg; Huitfeldt, Henrik S.; Wanner, Klaus T.; Danbolt, Niels C.

2012-01-01

The GABA transporters (GAT1, GAT2, GAT3, and BGT1) have mostly been discussed in relation to their potential roles in controlling the action of transmitter GABA in the nervous system. We have generated the first mice lacking the GAT2 (slc6a13) gene. Deletion of GAT2 (both mRNA and protein) neither affected growth, fertility, nor life span under nonchallenging rearing conditions. Immunocytochemistry showed that the GAT2 protein was predominantly expressed in the plasma membranes of periportal hepatocytes and in the basolateral membranes of proximal tubules in the renal cortex. This was validated by processing tissue from wild-type and knockout mice in parallel. Deletion of GAT2 reduced liver taurine levels by 50%, without affecting the expression of the taurine transporter TAUT. These results suggest an important role for GAT2 in taurine uptake from portal blood into liver. In support of this notion, GAT2-transfected HEK293 cells transported [3H]taurine. Furthermore, most of the uptake of [3H]GABA by cultured rat hepatocytes was due to GAT2, and this uptake was inhibited by taurine. GAT2 was not detected in brain parenchyma proper, excluding a role in GABA inactivation. It was, however, expressed in the leptomeninges and in a subpopulation of brain blood vessels. Deletion of GAT2 increased brain taurine levels by 20%, suggesting a taurine-exporting role for GAT2 in the brain. PMID:22896705

The Physiopathological Role of the Exchangers Belonging to the SLC37 Family

Directory of Open Access Journals (Sweden)

Anna Rita Cappello

2018-04-01

Full Text Available The human SLC37 gene family includes four proteins SLC37A1-4, localized in the endoplasmic reticulum (ER membrane. They have been grouped into the SLC37 family due to their sequence homology to the bacterial organophosphate/phosphate (Pi antiporter. SLC37A1-3 are the less characterized isoforms. SLC37A1 and SLC37A2 are Pi-linked glucose-6-phosphate (G6P antiporters, catalyzing both homologous (Pi/Pi and heterologous (G6P/Pi exchanges, whereas SLC37A3 transport properties remain to be clarified. Furthermore, SLC37A1 is highly homologous to the bacterial glycerol 3-phosphate permeases, so it is supposed to transport also glycerol-3-phosphate. The physiological role of SLC37A1-3 is yet to be further investigated. SLC37A1 seems to be required for lipid biosynthesis in cancer cell lines, SLC37A2 has been proposed as a vitamin D and a phospho-progesterone receptor target gene, while mutations in the SLC37A3 gene appear to be associated with congenital hyperinsulinism of infancy. SLC37A4, also known as glucose-6-phosphate translocase (G6PT, transports G6P from the cytoplasm into the ER lumen, working in complex with either glucose-6-phosphatase-α (G6Pase-α or G6Pase-β to hydrolyze intraluminal G6P to Pi and glucose. G6PT and G6Pase-β are ubiquitously expressed, whereas G6Pase-α is specifically expressed in the liver, kidney and intestine. G6PT/G6Pase-α complex activity regulates fasting blood glucose levels, whereas G6PT/G6Pase-β is required for neutrophil functions. G6PT deficiency is responsible for glycogen storage disease type Ib (GSD-Ib, an autosomal recessive disorder associated with both defective metabolic and myeloid phenotypes. Several kinds of mutations have been identified in the SLC37A4 gene, affecting G6PT function. An increased autoimmunity risk for GSD-Ib patients has also been reported, moreover, SLC37A4 seems to be involved in autophagy.

The Physiopathological Role of the Exchangers Belonging to the SLC37 Family

Science.gov (United States)

Cappello, Anna Rita; Curcio, Rosita; Lappano, Rosamaria; Maggiolini, Marcello; Dolce, Vincenza

2018-04-01

The human SLC37 gene family includes four proteins SLC37A1-4, localized in the endoplasmic reticulum (ER) membrane. They have been grouped into the SLC37 family due to their sequence homology to the bacterial organophosphate/phosphate (Pi) antiporter. SLC37A1-3 are the less characterized isoforms. SLC37A1 and SLC37A2 are Pi-linked glucose-6-phosphate (G6P) antiporters, catalyzing both homologous (Pi/Pi) and heterologous (G6P/Pi) exchanges, whereas SLC37A3 transport properties remain to be clarified. Furthermore, SLC37A1 is highly homologous to the bacterial glycerol 3-phosphate permeases, so it is supposed to transport also glycerol-3-phosphate. The physiological role of SLC37A1-3 is yet to be further investigated. SLC37A1 seems to be required for lipid biosynthesis in cancer cell lines, SLC37A2 has been proposed as a vitamin D and a phospho-progesterone receptor target gene, while mutations in the SLC37A3 gene appear to be associated with congenital hyperinsulinism of infancy. SLC37A4, also known as glucose-6-phosphate translocase (G6PT), transports G6P from the cytoplasm into the ER lumen, working in complex with either glucose-6-phosphatase-α (G6Pase-α) or G6Pase-β to hydrolyze intraluminal G6P to Pi and glucose. G6PT and G6Pase-β are ubiquitously expressed, whereas G6Pase-α is specifically expressed in the liver, kidney and intestine. G6PT/G6Pase-α complex activity regulates fasting blood glucose levels, whereas G6PT/G6Pase-β is required for neutrophil functions. G6PT deficiency is responsible for glycogen storage disease type Ib (GSD-Ib), an autosomal recessive disorder associated with both defective metabolic and myeloid phenotypes. Several kinds of mutations have been identified in the SLC37A4 gene, affecting G6PT function. An increased autoimmunity risk for GSD-Ib patients has also been reported, moreover, SLC37A4 seems to be involved in autophagy.

SLC6A1 gene involvement in susceptibility to attention-deficit/hyperactivity disorder: A case-control study and gene-environment interaction.

Science.gov (United States)

Yuan, Fang-Fen; Gu, Xue; Huang, Xin; Zhong, Yan; Wu, Jing

2017-07-03

Attention-deficit/hyperactivity disorder (ADHD) is an early onset childhood neurodevelopmental disorder with an estimated heritability of approximately 76%. We conducted a case-control study to explore the role of the SLC6A1 gene in ADHD. The genotypes of eight variants were determined using Sequenom MassARRAY technology. The participants in the study were 302 children with ADHD and 411 controls. ADHD symptoms were assessed using the Conners Parent Symptom Questionnaire. In our study, rs2944366 was consistently shown to be associated with the ADHD risk in the dominant model (odds ratio [OR]=0.554, 95% confidence interval [CI]=0.404-0.760), and nominally associated with Hyperactive index score (P=0.027). In addition, rs1170695 has been found to be associated with the ADHD risk in the addictive model (OR=1.457, 95%CI=1.173-1.809), while rs9990174 was associated with the Hyperactive index score (P=0.010). Intriguingly, gene-environmental interactions analysis consistently revealed the potential interactions of rs1170695 with blood lead (P mul =0.044) to modify the ADHD risk. Expression quantitative trait loci analysis suggested that these positive single nucleotide polymorphisms (SNPs) may mediate SLC6A1 gene expression. Therefore, our results suggest that selected SLC6A1 gene variants may have a significant effect on the ADHD risk. Copyright © 2017 Elsevier Inc. All rights reserved.

Two novel mutations in the SLC40A1 and HFE genes implicated in iron overload in a Spanish man.

Science.gov (United States)

Del-Castillo-Rueda, Alejandro; Moreno-Carralero, María-Isabel; Alvarez-Sala-Walther, Luis-Antonio; Cuadrado-Grande, Nuria; Enríquez-de-Salamanca, Rafael; Méndez, Manuel; Morán-Jiménez, María-Josefa

2011-03-01

The most common form of hemochromatosis is caused by mutations in the HFE gene. Rare forms of the disease are caused by mutations in other genes. We present a patient with hyperferritinemia and iron overload, and facial flushing. Magnetic resonance imaging was performed to measure hepatic iron overload, and a molecular study of the genes involved in iron metabolism was undertaken. The iron overload was similar to that observed in HFE hemochromatosis, and the patient was double heterozygous for two novel mutations, c.-20G>A and c.718A>G (p.K240E), in the HFE and ferroportin (FPN1 or SLC40A1) genes, respectively. Hyperferritinemia and facial flushing improved after phlebotomy. Two of the patient's children were also studied, and the daughter was heterozygous for the mutation in the SLC40A1 gene, although she did not have hyperferritinemia. The patient presented a mild iron overload phenotype probably because of the two novel mutations in the HFE and SLC40A1 genes. © 2011 John Wiley & Sons A/S.

Polymorphism Study on SLC30A8 and Its Association with Type 2 Diabetes

Directory of Open Access Journals (Sweden)

M. Vignesh

2016-11-01

Full Text Available Type 2 diabetes mellitus (T2DM is one of the threatening disorders in the world. It affects people of all ages. Type 2 diabetes mellitus is a condition in which the glucose level in the blood is elevated due to improper function of the secretion of insulin from beta cells of the pancreas. It is a multifactorial disease because it is caused by both environmental and hereditary factors. One of the genes which play an important role in type 2 diabetes mellitus is SLC30A8 which encodes for zinc transporter ZnT8. The common polymorphic site for SLC30A8 is rs13266634. This single-nucleotide polymorphism leads to type 2 diabetes mellitus by replacing the arginine residue with tryptophan residue. This review mainly focuses on the polymorphic studies in the gene SLC30A8 and its association with type 2 diabetes mellitus.

The role of SLC2A1 mutations in myoclonic astatic epilepsy and absence epilepsy, and the estimated frequency of GLUT1 deficiency syndrome

DEFF Research Database (Denmark)

Larsen, Jan; Johannesen, Katrine Marie; Ek, Jakob

2015-01-01

The first mutations identified in SLC2A1, encoding the glucose transporter type 1 (GLUT1) protein of the blood-brain barrier, were associated with severe epileptic encephalopathy. Recently, dominant SLC2A1 mutations were found in rare autosomal dominant families with various forms of epilepsy inc...

Reduced Slc6a15 in Nucleus Accumbens D2-Neurons Underlies Stress Susceptibility.

Science.gov (United States)

Chandra, Ramesh; Francis, T Chase; Nam, Hyungwoo; Riggs, Lace M; Engeln, Michel; Rudzinskas, Sarah; Konkalmatt, Prasad; Russo, Scott J; Turecki, Gustavo; Iniguez, Sergio D; Lobo, Mary Kay

2017-07-05

Previous research demonstrates that Slc6a15, a neutral amino acid transporter, is associated with depression susceptibility. However, no study examined Slc6a15 in the ventral striatum [nucleus accumbens (NAc)] in depression. Given our previous characterization of Slc6a15 as a striatal dopamine receptor 2 (D2)-neuron-enriched gene, we examined the role of Slc6a15 in NAc D2-neurons in mediating susceptibility to stress in male mice. First, we showed that Slc6a15 mRNA was reduced in NAc of mice susceptible to chronic social defeat stress (CSDS), a paradigm that produces behavioral and molecular adaptations that resemble clinical depression. Consistent with our preclinical data, we observed Slc6a15 mRNA reduction in NAc of individuals with major depressive disorder (MDD). The Slc6a15 reduction in NAc occurred selectively in D2-neurons. Next, we used Cre-inducible viruses combined with D2-Cre mice to reduce or overexpress Slc6a15 in NAc D2-neurons. Slc6a15 reduction in D2-neurons caused enhanced susceptibility to a subthreshold social defeat stress (SSDS) as observed by reduced social interaction, while a reduction in social interaction following CSDS was not observed when Slc6a15 expression in D2-neurons was restored. Finally, since both D2-medium spiny neurons (MSNs) and D2-expressing choline acetyltransferase (ChAT) interneurons express Slc6a15, we examined Slc6a15 protein in these interneurons after CSDS. Slc6a15 protein was unaltered in ChAT interneurons. Consistent with this, reducing Slc5a15 selectively in NAc D2-MSNs, using A2A-Cre mice that express Cre selectively in D2-MSNs, caused enhanced susceptibility to SSDS. Collectively, our data demonstrate that reduced Slc6a15 in NAc occurs in MDD individuals and that Slc6a15 reduction in NAc D2-neurons underlies stress susceptibility. SIGNIFICANCE STATEMENT Our study demonstrates a role for reduced Slc6a15, a neutral amino acid transporter, in nucleus accumbens (NAc) in depression and stress susceptibility. The

SLC3A1 and SLC7A9 mutations in autosomal recessive or dominant canine cystinuria: a new classification system.

Science.gov (United States)

Brons, A-K; Henthorn, P S; Raj, K; Fitzgerald, C A; Liu, J; Sewell, A C; Giger, U

2013-01-01

Cystinuria, one of the first recognized inborn errors of metabolism, has been reported in many dog breeds. To determine urinary cystine concentrations, inheritance, and mutations in the SLC3A1 and SLC7A9 genes associated with cystinuria in 3 breeds. Mixed and purebred Labrador Retrievers (n = 6), Australian Cattle Dogs (6), Miniature Pinschers (4), and 1 mixed breed dog with cystine urolithiasis, relatives and control dogs. Urinary cystinuria and aminoaciduria was assessed and exons of the SLC3A1 and SLC7A9 genes were sequenced from genomic DNA. In each breed, male and female dogs, independent of neuter status, were found to form calculi. A frameshift mutation in SLC3A1 (c.350delG) resulting in a premature stop codon was identified in autosomal-recessive (AR) cystinuria in Labrador Retrievers and mixed breed dogs. A 6 bp deletion (c.1095_1100del) removing 2 threonines in SLC3A1 was found in autosomal-dominant (AD) cystinuria with a more severe phenotype in homozygous than in heterozygous Australian Cattle Dogs. A missense mutation in SLC7A9 (c.964G>A) was discovered in AD cystinuria in Miniature Pinschers with only heterozygous affected dogs observed to date. Breed-specific DNA tests were developed, but the prevalence of each mutation remains unknown. These studies describe the first AD inheritance and the first putative SLC7A9 mutation to cause cystinuria in dogs and expand our understanding of this phenotypically and genetically heterogeneous disease, leading to a new classification system for canine cystinuria and better therapeutic management and genetic control in these breeds. Copyright © 2013 by the American College of Veterinary Internal Medicine.

Plasma Membrane Na+-Coupled Citrate Transporter (SLC13A5 and Neonatal Epileptic Encephalopathy

Directory of Open Access Journals (Sweden)

Yangzom D. Bhutia

2017-02-01

Full Text Available SLC13A5 is a Na+-coupled transporter for citrate that is expressed in the plasma membrane of specific cell types in the liver, testis, and brain. It is an electrogenic transporter with a Na+:citrate3− stoichiometry of 4:1. In humans, the Michaelis constant for SLC13A5 to transport citrate is ~600 μM, which is physiologically relevant given that the normal concentration of citrate in plasma is in the range of 150–200 μM. Li+ stimulates the transport function of human SLC13A5 at concentrations that are in the therapeutic range in patients on lithium therapy. Human SLC13A5 differs from rodent Slc13a5 in two important aspects: the affinity of the human transporter for citrate is ~30-fold less than that of the rodent transporter, thus making human SLC13A5 a low-affinity/high-capacity transporter and the rodent Slc13a5 a high-affinity/low-capacity transporter. In the liver, SLC13A5 is expressed exclusively in the sinusoidal membrane of the hepatocytes, where it plays a role in the uptake of circulating citrate from the sinusoidal blood for metabolic use. In the testis, the transporter is expressed only in spermatozoa, which is also only in the mid piece where mitochondria are located; the likely function of the transporter in spermatozoa is to mediate the uptake of citrate present at high levels in the seminal fluid for subsequent metabolism in the sperm mitochondria to generate biological energy, thereby supporting sperm motility. In the brain, the transporter is expressed mostly in neurons. As astrocytes secrete citrate into extracellular medium, the potential function of SLC13A5 in neurons is to mediate the uptake of circulating citrate and astrocyte-released citrate for subsequent metabolism. Slc13a5-knockout mice have been generated; these mice do not have any overt phenotype but are resistant to experimentally induced metabolic syndrome. Recently however, loss-of-function mutations in human SLC13A5 have been found to cause severe epilepsy

Deletions at SLC18A1 increased the risk of CRC and lower SLC18A1 expression associated with poor CRC outcome.

Science.gov (United States)

Zhang, Dandan; Li, Zhenli; Xu, Xiaohong; Zhou, Dan; Tang, Shunli; Yin, Xiaoyang; Xu, Fangying; Li, Hui; Zhou, Yuan; Zhu, Tao; Deng, Hong; Zhang, Shuai; Huang, Qiong; Wang, Jing; Yin, Wei; Zhu, Yimin; Lai, Maode

2017-10-26

Copy number variations (CNVs) contribute to the development of colorectal cancer (CRC). We conducted a two-stage association study to identify CNV risk loci for CRC. We performed a gene-based rare CNV study on 694 sporadic CRC and 1641 controls using Illumina Human-OmniExpress-12v1.0 BeadChips, and further replicated in 934 CRC cases and 2680 controls for risk CNVs by using TaqMan Copy Number Assay. Tumor buddings, cancer cells in the center of primary tumor and normal intestinal epithelial cells were captured using laser capture microdissection (LCM) and were assayed using AffymetrixGeneChip® Human Genome U133 Plus 2.0 Array. In addition, The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus data were assessed for the effects of risk CNVs. We found that germline deletions affecting the last six exons of SLC18A1 significantly associated with CRC with a combined P value of 6.4 × 10-5 by a two-stage analysis. Both in TCGA CRC RNA seq dataset and GDS4382, SLC18A1 was significantly down regulated in CRC tissues than in paired normal tissues (N = 32 and 17 pairs, P = 0.004 and 0.009, respectively). In LCM samples, similar observations were obtained that the expression levels of SLC18A1 in the tumor buddings, cancer cells in the center of primary tumor, and stroma of both tumor budding and cancer cells were lower than normal intestinal epithelial and stromal cells (fold change = 0.17-0.62, 0.12-0.57 and 0.37-0.68, respectively). In summary, the germline deletions at SLC18A1 contributed to the development of CRC. The role of SLC18A1 required further exploration. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Function and expression of the proton-coupled amino acid transporter Slc36a1 along the rat gastrointestinal tract

DEFF Research Database (Denmark)

Broberg, M. L.; Holm, Rasmus Koldborg; Tønsberg, H

2012-01-01

BACKGROUND AND PURPOSE: Intestinal absorption via membrane transporters may determine the pharmacokinetics of drug compounds. The hypothesis is that oral absorption of gaboxadol (4, 5, 6, 7-tetrahydroisoxazolo [5,4-c] pyridine-3-ol) in rats occurs via the proton-coupled amino acid transporter, r....... The intestinal expression of rSlc36a1 mRNA was measured by quantitative real-time PCR (q-RT-PCR). Furthermore, the hPAT1-/rPAT1-mediated transport of gaboxadol or L-proline was studied in hPAT1-expressing X. laevis oocytes, Caco-2 cell monolayers and excised segments of the rat intestine. KEY RESULTS......). The in vitro carrier-mediated uptake rate of L-proline in the excised intestinal segments was highest in the mid jejunum and low in the colon. The in vitro uptake and the in vivo absorption correlated with the expression of rSlc36a1 mRNA along the rat intestine. CONCLUSIONS AND IMPLICATIONS: The results...

Interaction between the SLC19A1 gene and maternal first trimester fever on offspring neural tube defects.

Science.gov (United States)

Pei, Lijun; Zhu, Huiping; Ye, Rongwei; Wu, Jilei; Liu, Jianmeng; Ren, Aiguo; Li, Zhiwen; Zheng, Xiaoying

2015-01-01

Many studies have indicated that the reduced folate carrier gene (SLC19A1) is associated with an increased risk of neural tube defects (NTDs). However, the interaction between the SLC19A1 gene variant and maternal fever exposure and NTD risk remains unknown. The aim of this study was to investigate whether the risk for NTDs was influenced by the interactions between the SLC19A1 (rs1051266) variant and maternal first trimester fever. We investigated the potential interaction between maternal first trimester fever and maternal or offspring SLC19A1 polymorphism through a population-based case-control study. One hundred and four nuclear families with NTDs and 100 control families with nonmal newborns were included in the study. SLC19A1 polymorphism was determined using polymerase chain reaction-restricted fragment length polymorphism. Mothers who had the GG/GA genotype and first trimester fever had an elevated risk of NTDs (adjusted odds ratio, 11.73; 95% confidence interval, 3.02-45.58) as compared to absence of maternal first trimester fever and AA genotype after adjusting for maternal education, paternal education, and age, and had a significant interactive coefficient (γ = 3.17) between maternal GG/GA genotype and first trimester fever. However, there was no interaction between offspring's GG/GA genotype and maternal first trimester fever (the interactive coefficient γ = 0.97) after adjusting for confounding factors. Our findings suggested that the risk of NTDs was potentially influenced by a gene-environment interaction between maternal SLC19A1 rs1051266 GG/GA genotype and first trimester fever. Maternal GG/GA genotype may strengthen the effect of maternal fever exposure on NTD risk in this Chinese population. © 2014 Wiley Periodicals, Inc.

Complex analysis of urate transporters SLC2A9, SLC22A12 and functional characterization of non-synonymous allelic variants of GLUT9 in the Czech population: no evidence of effect on hyperuricemia and gout.

Directory of Open Access Journals (Sweden)

Olha Hurba

Full Text Available OBJECTIVE: Using European descent Czech populations, we performed a study of SLC2A9 and SLC22A12 genes previously identified as being associated with serum uric acid concentrations and gout. This is the first study of the impact of non-synonymous allelic variants on the function of GLUT9 except for patients suffering from renal hypouricemia type 2. METHODS: The cohort consisted of 250 individuals (150 controls, 54 nonspecific hyperuricemics and 46 primary gout and/or hyperuricemia subjects. We analyzed 13 exons of SLC2A9 (GLUT9 variant 1 and GLUT9 variant 2 and 10 exons of SLC22A12 by PCR amplification and sequenced directly. Allelic variants were prepared and their urate uptake and subcellular localization were studied by Xenopus oocytes expression system. The functional studies were analyzed using the non-parametric Wilcoxon and Kruskall-Wallis tests; the association study used the Fisher exact test and linear regression approach. RESULTS: We identified a total of 52 sequence variants (12 unpublished. Eight non-synonymous allelic variants were found only in SLC2A9: rs6820230, rs2276961, rs144196049, rs112404957, rs73225891, rs16890979, rs3733591 and rs2280205. None of these variants showed any significant difference in the expression of GLUT9 and in urate transport. In the association study, eight variants showed a possible association with hyperuricemia. However, seven of these were in introns and the one exon located variant, rs7932775, did not show a statistically significant association with serum uric acid concentration. CONCLUSION: Our results did not confirm any effect of SLC22A12 and SLC2A9 variants on serum uric acid concentration. Our complex approach using association analysis together with functional and immunohistochemical characterization of non-synonymous allelic variants did not show any influence on expression, subcellular localization and urate uptake of GLUT9.

Prostaglandin transporter (OATP2A1/SLCO2A1) contributes to local disposition of eicosapentaenoic acid-derived PGE3.

Science.gov (United States)

Gose, Tomoka; Nakanishi, Takeo; Kamo, Shunsuke; Shimada, Hiroaki; Otake, Katsumasa; Tamai, Ikumi

2016-01-01

Eicosapentaenoic acid (EPA)-derived prostaglandin E3 (PGE3) possesses an anti-inflammatory effect; however, information for transporters that regulate its peri-cellular concentration is limited. The present study, therefore, aimed to clarify transporters involved in local disposition of PGE3. PGE3 uptake was assessed in HEK293 cells transfected with OATP2A1/SLCO2A1, OATP1B1/SLCO1B1, OATP2B1/SLCO2B1, OAT1/SLC22A6, OCT1/SLC22A1 or OCT2/SLC22A2 genes, compared with HEK293 cells transfected with plasmid vector alone (Mock). PGE3 uptake by OATP2A1-expressing HEK293 cells (HEK/2A1) was the highest and followed by HEK/1B1, while no significantly higher uptake of PGE3 than Mock cells was detected by other transporters. Saturation kinetics in PGE3 uptake by HEK/2A1 estimated the Km as 7.202 ± 0.595 μM, which was 22 times higher than that of PGE2 (Km=0.331 ± 0.131 μM). Furthermore, tissue disposition of PGE3 was examined in wild-type (WT) and Slco2a1-deficient (Slco2a1(-/-)) mice after oral administration of EPA ethyl ester (EPA-E) when they underwent intraperitoneal injection of endotoxin (e.g., lipopolysaccharide). PGE3 concentration was significantly higher in the lung, and tended to increase in the colon, stomach, and kidney of Slco2a1(-/-), compared to WT mice. Ratio of PGE2 metabolite 15-keto PGE2 over PGE2 concentration was significantly lower in the lung and colon of Slco2a1(-/-) than that of WT mice, suggesting that PGE3 metabolism is downregulated in Slco2a1(-/-) mice. In conclusion, PGE3 was found to be a substrate of OATP2A1, and local disposition of PGE3 could be regulated by OATP2A1 at least in the lung. Copyright © 2015 Elsevier Inc. All rights reserved.

Common Genetic Variation In Cellular Transport Genes and Epithelial Ovarian Cancer (EOC) Risk.

Science.gov (United States)

Chornokur, Ganna; Lin, Hui-Yi; Tyrer, Jonathan P; Lawrenson, Kate; Dennis, Joe; Amankwah, Ernest K; Qu, Xiaotao; Tsai, Ya-Yu; Jim, Heather S L; Chen, Zhihua; Chen, Ann Y; Permuth-Wey, Jennifer; Aben, Katja K H; Anton-Culver, Hoda; Antonenkova, Natalia; Bruinsma, Fiona; Bandera, Elisa V; Bean, Yukie T; Beckmann, Matthias W; Bisogna, Maria; Bjorge, Line; Bogdanova, Natalia; Brinton, Louise A; Brooks-Wilson, Angela; Bunker, Clareann H; Butzow, Ralf; Campbell, Ian G; Carty, Karen; Chang-Claude, Jenny; Cook, Linda S; Cramer, Daniel W; Cunningham, Julie M; Cybulski, Cezary; Dansonka-Mieszkowska, Agnieszka; du Bois, Andreas; Despierre, Evelyn; Dicks, Ed; Doherty, Jennifer A; Dörk, Thilo; Dürst, Matthias; Easton, Douglas F; Eccles, Diana M; Edwards, Robert P; Ekici, Arif B; Fasching, Peter A; Fridley, Brooke L; Gao, Yu-Tang; Gentry-Maharaj, Aleksandra; Giles, Graham G; Glasspool, Rosalind; Goodman, Marc T; Gronwald, Jacek; Harrington, Patricia; Harter, Philipp; Hein, Alexander; Heitz, Florian; Hildebrandt, Michelle A T; Hillemanns, Peter; Hogdall, Claus K; Hogdall, Estrid; Hosono, Satoyo; Jakubowska, Anna; Jensen, Allan; Ji, Bu-Tian; Karlan, Beth Y; Kelemen, Linda E; Kellar, Mellissa; Kiemeney, Lambertus A; Krakstad, Camilla; Kjaer, Susanne K; Kupryjanczyk, Jolanta; Lambrechts, Diether; Lambrechts, Sandrina; Le, Nhu D; Lee, Alice W; Lele, Shashi; Leminen, Arto; Lester, Jenny; Levine, Douglas A; Liang, Dong; Lim, Boon Kiong; Lissowska, Jolanta; Lu, Karen; Lubinski, Jan; Lundvall, Lene; Massuger, Leon F A G; Matsuo, Keitaro; McGuire, Valerie; McLaughlin, John R; McNeish, Iain; Menon, Usha; Milne, Roger L; Modugno, Francesmary; Moysich, Kirsten B; Ness, Roberta B; Nevanlinna, Heli; Eilber, Ursula; Odunsi, Kunle; Olson, Sara H; Orlow, Irene; Orsulic, Sandra; Weber, Rachel Palmieri; Paul, James; Pearce, Celeste L; Pejovic, Tanja; Pelttari, Liisa M; Pike, Malcolm C; Poole, Elizabeth M; Risch, Harvey A; Rosen, Barry; Rossing, Mary Anne; Rothstein, Joseph H; Rudolph, Anja; Runnebaum, Ingo B; Rzepecka, Iwona K; Salvesen, Helga B; Schernhammer, Eva; Schwaab, Ira; Shu, Xiao-Ou; Shvetsov, Yurii B; Siddiqui, Nadeem; Sieh, Weiva; Song, Honglin; Southey, Melissa C; Spiewankiewicz, Beata; Sucheston, Lara; Teo, Soo-Hwang; Terry, Kathryn L; Thompson, Pamela J; Thomsen, Lotte; Tangen, Ingvild L; Tworoger, Shelley S; van Altena, Anne M; Vierkant, Robert A; Vergote, Ignace; Walsh, Christine S; Wang-Gohrke, Shan; Wentzensen, Nicolas; Whittemore, Alice S; Wicklund, Kristine G; Wilkens, Lynne R; Wu, Anna H; Wu, Xifeng; Woo, Yin-Ling; Yang, Hannah; Zheng, Wei; Ziogas, Argyrios; Hasmad, Hanis N; Berchuck, Andrew; Iversen, Edwin S; Schildkraut, Joellen M; Ramus, Susan J; Goode, Ellen L; Monteiro, Alvaro N A; Gayther, Simon A; Narod, Steven A; Pharoah, Paul D P; Sellers, Thomas A; Phelan, Catherine M

2015-01-01

Defective cellular transport processes can lead to aberrant accumulation of trace elements, iron, small molecules and hormones in the cell, which in turn may promote the formation of reactive oxygen species, promoting DNA damage and aberrant expression of key regulatory cancer genes. As DNA damage and uncontrolled proliferation are hallmarks of cancer, including epithelial ovarian cancer (EOC), we hypothesized that inherited variation in the cellular transport genes contributes to EOC risk. In total, DNA samples were obtained from 14,525 case subjects with invasive EOC and from 23,447 controls from 43 sites in the Ovarian Cancer Association Consortium (OCAC). Two hundred seventy nine SNPs, representing 131 genes, were genotyped using an Illumina Infinium iSelect BeadChip as part of the Collaborative Oncological Gene-environment Study (COGS). SNP analyses were conducted using unconditional logistic regression under a log-additive model, and the FDR q<0.2 was applied to adjust for multiple comparisons. The most significant evidence of an association for all invasive cancers combined and for the serous subtype was observed for SNP rs17216603 in the iron transporter gene HEPH (invasive: OR = 0.85, P = 0.00026; serous: OR = 0.81, P = 0.00020); this SNP was also associated with the borderline/low malignant potential (LMP) tumors (P = 0.021). Other genes significantly associated with EOC histological subtypes (p<0.05) included the UGT1A (endometrioid), SLC25A45 (mucinous), SLC39A11 (low malignant potential), and SERPINA7 (clear cell carcinoma). In addition, 1785 SNPs in six genes (HEPH, MGST1, SERPINA, SLC25A45, SLC39A11 and UGT1A) were imputed from the 1000 Genomes Project and examined for association with INV EOC in white-European subjects. The most significant imputed SNP was rs117729793 in SLC39A11 (per allele, OR = 2.55, 95% CI = 1.5-4.35, p = 5.66x10-4). These results, generated on a large cohort of women, revealed associations between inherited cellular transport

AVPR1a and SLC6A4 Gene Polymorphisms Are Associated with Creative Dance Performance.

Directory of Open Access Journals (Sweden)

2005-09-01

Full Text Available Dancing, which is integrally related to music, likely has its origins close to the birth of Homo sapiens, and throughout our history, dancing has been universally practiced in all societies. We hypothesized that there are differences among individuals in aptitude, propensity, and need for dancing that may partially be based on differences in common genetic polymorphisms. Identifying such differences may lead to an understanding of the neurobiological basis of one of mankind's most universal and appealing behavioral traits-dancing. In the current study, 85 current performing dancers and their parents were genotyped for the serotonin transporter (SLC6A4: promoter region HTTLPR and intron 2 VNTR and the arginine vasopressin receptor 1a (AVPR1a: promoter microsatellites RS1 and RS3. We also genotyped 91 competitive athletes and a group of nondancers/nonathletes (n = 872 subjects from 414 families. Dancers scored higher on the Tellegen Absorption Scale, a questionnaire that correlates positively with spirituality and altered states of consciousness, as well as the Reward Dependence factor in Cloninger's Tridimensional Personality Questionnaire, a measure of need for social contact and openness to communication. Highly significant differences in AVPR1a haplotype frequencies (RS1 and RS3, especially when conditional on both SLC6A4 polymorphisms (HTTLPR and VNTR, were observed between dancers and athletes using the UNPHASED program package (Cocaphase: likelihood ratio test [LRS] = 89.23, p = 0.000044. Similar results were obtained when dancers were compared to nondancers/nonathletes (Cocaphase: LRS = 92.76, p = 0.000024. These results were confirmed using a robust family-based test (Tdtphase: LRS = 46.64, p = 0.010. Association was also observed between Tellegen Absorption Scale scores and AVPR1a (Qtdtphase: global chi-square = 26.53, p = 0.047, SLC6A4 haplotypes (Qtdtphase: chi-square = 2.363, p = 0.018, and AVPR1a conditional on SCL6A4 (Tdtphase: LRS

AVPR1a and SLC6A4 gene polymorphisms are associated with creative dance performance.

Directory of Open Access Journals (Sweden)

Rachel Bachner-Melman

2005-09-01

Full Text Available Dancing, which is integrally related to music, likely has its origins close to the birth of Homo sapiens, and throughout our history, dancing has been universally practiced in all societies. We hypothesized that there are differences among individuals in aptitude, propensity, and need for dancing that may partially be based on differences in common genetic polymorphisms. Identifying such differences may lead to an understanding of the neurobiological basis of one of mankind's most universal and appealing behavioral traits--dancing. In the current study, 85 current performing dancers and their parents were genotyped for the serotonin transporter (SLC6A4: promoter region HTTLPR and intron 2 VNTR and the arginine vasopressin receptor 1a (AVPR1a: promoter microsatellites RS1 and RS3. We also genotyped 91 competitive athletes and a group of nondancers/nonathletes (n = 872 subjects from 414 families. Dancers scored higher on the Tellegen Absorption Scale, a questionnaire that correlates positively with spirituality and altered states of consciousness, as well as the Reward Dependence factor in Cloninger's Tridimensional Personality Questionnaire, a measure of need for social contact and openness to communication. Highly significant differences in AVPR1a haplotype frequencies (RS1 and RS3, especially when conditional on both SLC6A4 polymorphisms (HTTLPR and VNTR, were observed between dancers and athletes using the UNPHASED program package (Cocaphase: likelihood ratio test [LRS] = 89.23, p = 0.000044. Similar results were obtained when dancers were compared to nondancers/nonathletes (Cocaphase: LRS = 92.76, p = 0.000024. These results were confirmed using a robust family-based test (Tdtphase: LRS = 46.64, p = 0.010. Association was also observed between Tellegen Absorption Scale scores and AVPR1a (Qtdtphase: global chi-square = 26.53, p = 0.047, SLC6A4 haplotypes (Qtdtphase: chi-square = 2.363, p = 0.018, and AVPR1a conditional on SCL6A4 (Tdtphase: LRS

Transport by SLC5A8 with subsequent inhibition of histone deacetylase 1 (HDAC1) and HDAC3 underlies the antitumor activity of 3-bromopyruvate.

Science.gov (United States)

Thangaraju, Muthusamy; Karunakaran, Senthil K; Itagaki, Shiro; Gopal, Elangovan; Elangovan, Selvakumar; Prasad, Puttur D; Ganapathy, Vadivel

2009-10-15

3-bromopyruvate is an alkylating agent with antitumor activity. It is currently believed that blockade of adenosine triphosphate production from glycolysis and mitochondria is the primary mechanism responsible for this antitumor effect. The current studies uncovered a new and novel mechanism for the antitumor activity of 3-bromopyruvate. The transport of 3-bromopyruvate by sodium-coupled monocarboxylate transporter SMCT1 (SLC5A8), a tumor suppressor and a sodium (Na+)-coupled, electrogenic transporter for short-chain monocarboxylates, was studied using a mammalian cell expression and the Xenopus laevis oocyte expression systems. The effect of 3-bromopyruvate on histone deacetylases (HDACs) was monitored using the lysate of the human breast cancer cell line MCF7 and human recombinant HDAC isoforms as the enzyme sources. Cell viability was monitored by fluorescence-activated cell-sorting analysis and colony-formation assay. The acetylation status of histone H4 was evaluated by Western blot analysis. 3-Bromopyruvate is a transportable substrate for SLC5A8, and that transport process is Na+-coupled and electrogenic. MCF7 cells did not express SLC5A8 and were not affected by 3-bromopyruvate. However, when transfected with SLC5A8 or treated with inhibitors of DNA methylation, these cells underwent apoptosis in the presence of 3-bromopyruvate. This cell death was associated with the inhibition of HDAC1/HDAC3. Studies with different isoforms of human recombinant HDACs identified HDAC1 and HDAC3 as the targets for 3-bromopyruvate. 3-Bromopyruvate was transported into cells actively through the tumor suppressor SLC5A8, and the process was energized by an electrochemical Na+ gradient. Ectopic expression of the transporter in MCF7 cells led to apoptosis, and the mechanism involved the inhibition of HDAC1/HDAC3. Copyright (c) 2009 American Cancer Society.

Drug Clearance from Cerebrospinal Fluid Mediated by Organic Anion Transporters 1 (Slc22a6) and 3 (Slc22a8) at Arachnoid Membrane of Rats.

Science.gov (United States)

Zhang, Zhengyu; Tachikawa, Masanori; Uchida, Yasuo; Terasaki, Tetsuya

2018-03-05

Although arachnoid mater epithelial cells form the blood-arachnoid barrier (BAB), acting as a blood-CSF interface, it has been generally considered that the BAB is impermeable to water-soluble substances and plays a largely passive role. Here, we aimed to clarify the function of transporters at the BAB in regulating CSF clearance of water-soluble organic anion drugs based on quantitative targeted absolute proteomics (QTAP) and in vivo analyses. Protein expression levels of 61 molecules, including 19 ATP-binding-cassette (ABC) transporters and 32 solute-carrier (SLC) transporters, were measured in plasma membrane fraction of rat leptomeninges using QTAP. Thirty-three proteins were detected; others were under the quantification limits. Expression levels of multidrug resistance protein 1 (Mdr1a/P-gp/Abcb1a) and breast cancer resistance protein (Bcrp/Abcg2) were 16.6 and 3.27 fmol/μg protein (51.9- and 9.82-fold greater than in choroid plexus, respectively). Among those organic anion transporters detected only at leptomeninges, not choroid plexus, organic anion transporter 1 (oat1/Slc22a6) showed the greatest expression (2.73 fmol/μg protein). On the other hand, the protein expression level of oat3 at leptomeninges was 6.65 fmol/μg protein, and the difference from choroid plexus was within two-fold. To investigate oat1's role, we injected para-aminohippuric acid (PAH) with or without oat1 inhibitors into cisterna magna (to minimize the contribution of choroid plexus function) of rats. A bulk flow marker, FITC-inulin, was not taken up from CSF up to 15 min, whereas uptake clearance of PAH was 26.5 μL/min. PAH uptake was completely blocked by 3 mM cephalothin (inhibits both oat1 and oat3), while 17% of PAH uptake was inhibited by 0.2 mM cephalothin (selectively inhibits oat3). These results indicate that oat1 and oat3 at the BAB provide a distinct clearance pathway of organic anion drugs from CSF independently of choroid plexus.

Mutations in the GABA Transporter SLC6A1 Cause Epilepsy with Myoclonic-Atonic Seizures

Science.gov (United States)

Carvill, Gemma L.; McMahon, Jacinta M.; Schneider, Amy; Zemel, Matthew; Myers, Candace T.; Saykally, Julia; Nguyen, John; Robbiano, Angela; Zara, Federico; Specchio, Nicola; Mecarelli, Oriano; Smith, Robert L.; Leventer, Richard J.; Møller, Rikke S.; Nikanorova, Marina; Dimova, Petia; Jordanova, Albena; Petrou, Steven; Helbig, Ingo; Striano, Pasquale; Weckhuysen, Sarah; Berkovic, Samuel F.; Scheffer, Ingrid E.; Mefford, Heather C.

2015-01-01

GAT-1, encoded by SLC6A1, is one of the major gamma-aminobutyric acid (GABA) transporters in the brain and is responsible for re-uptake of GABA from the synapse. In this study, targeted resequencing of 644 individuals with epileptic encephalopathies led to the identification of six SLC6A1 mutations in seven individuals, all of whom have epilepsy with myoclonic-atonic seizures (MAE). We describe two truncations and four missense alterations, all of which most likely lead to loss of function of GAT-1 and thus reduced GABA re-uptake from the synapse. These individuals share many of the electrophysiological properties of Gat1-deficient mice, including spontaneous spike-wave discharges. Overall, pathogenic mutations occurred in 6/160 individuals with MAE, accounting for ∼4% of unsolved MAE cases. PMID:25865495

Serotonin Transporter Gene ("SLC6A4") Methylation Associates with Neonatal Intensive Care Unit Stay and 3-month-old Temperament in Preterm Infants

Science.gov (United States)

Montirosso, Rosario; Provenzi, Livio; Fumagalli, Monica; Sirgiovanni, Ida; Giorda, Roberto; Pozzoli, Uberto; Beri, Silvana; Menozzi, Giorgia; Tronick, Ed; Morandi, Francesco; Mosca, Fabio; Borgatti, Renato

2016-01-01

Preterm birth and Neonatal Intensive Care Unit (NICU) stay are early adverse stressful experiences, which may result in an altered temperamental profile. The serotonin transporter gene ("SLC6A4"), which has been linked to infant temperament, is susceptible to epigenetic regulation associated with early stressful experience. This study…

Relationship between ZnT8Ab, the SLC30A8 gene and disease progression in children with newly diagnosed type 1 diabetes

DEFF Research Database (Denmark)

Nielsen, Lotte B; Vaziri-Sani, Fariba; Pörksen, Sven

2011-01-01

Autoantibodies against the newly established autoantigen in type 1 diabetes, zinc transporter 8, ZnT8, are presented as two types, ZnT8RAb and ZnT8WAb. The rs13266634 variant of the SLC30A8 gene has recently been found to determine the type of ZnT8Ab. The aim of this study was to explore the impact...

A 40-bp VNTR polymorphism in the 3'-untranslated region of DAT1/SLC6A3 is associated with ADHD but not with alcoholism.

Science.gov (United States)

Šerý, Omar; Paclt, Ivo; Drtílková, Ivana; Theiner, Pavel; Kopečková, Marta; Zvolský, Petr; Balcar, Vladimir J

2015-06-11

ADHD and alcoholism are psychiatric diseases with pathophysiology related to dopamine system. DAT1 belongs to the SLC6 family of transporters and is involved in the regulation of extracellular dopamine levels. A 40 bp variable number tandem repeat (VNTR) polymorphism in the 3'-untranslated region of DAT1/SLC6A3 gene was previously reported to be associated with various phenotypes involving disturbed regulation of dopaminergic neurotransmission. A total of 1312 subjects were included and genotyped for 40 bp VNTR polymorphism of DAT1/SLC6A3 gene in this study (441 alcoholics, 400 non-alcoholic controls, 218 ADHD children and 253 non ADHD children). Using miRBase software, we have performed a computer analysis of VNTR part of DAT1 gene for presence of miRNA binding sites. We have found significant relationships between ADHD and the 40 bp VNTR polymorphisms of DAT1/SLC6A3 gene (P VNTR polymorphism of DAT1/SLC6A3 gene has been detected. We have found an association between 40 bp VNTR polymorphism of DAT1/SLC6A3 gene and ADHD in the Czech population; in a broad agreement with studies in other population samples. Furthermore, we detected rare genotypes 8/10, 7/10 and 10/11 present in ADHD boys only and identified miRNAs that should be looked at as potential novel targets in the research on ADHD.

Common Genetic Variation In Cellular Transport Genes and Epithelial Ovarian Cancer (EOC Risk.

Directory of Open Access Journals (Sweden)

Ganna Chornokur

Full Text Available Defective cellular transport processes can lead to aberrant accumulation of trace elements, iron, small molecules and hormones in the cell, which in turn may promote the formation of reactive oxygen species, promoting DNA damage and aberrant expression of key regulatory cancer genes. As DNA damage and uncontrolled proliferation are hallmarks of cancer, including epithelial ovarian cancer (EOC, we hypothesized that inherited variation in the cellular transport genes contributes to EOC risk.In total, DNA samples were obtained from 14,525 case subjects with invasive EOC and from 23,447 controls from 43 sites in the Ovarian Cancer Association Consortium (OCAC. Two hundred seventy nine SNPs, representing 131 genes, were genotyped using an Illumina Infinium iSelect BeadChip as part of the Collaborative Oncological Gene-environment Study (COGS. SNP analyses were conducted using unconditional logistic regression under a log-additive model, and the FDR q<0.2 was applied to adjust for multiple comparisons.The most significant evidence of an association for all invasive cancers combined and for the serous subtype was observed for SNP rs17216603 in the iron transporter gene HEPH (invasive: OR = 0.85, P = 0.00026; serous: OR = 0.81, P = 0.00020; this SNP was also associated with the borderline/low malignant potential (LMP tumors (P = 0.021. Other genes significantly associated with EOC histological subtypes (p<0.05 included the UGT1A (endometrioid, SLC25A45 (mucinous, SLC39A11 (low malignant potential, and SERPINA7 (clear cell carcinoma. In addition, 1785 SNPs in six genes (HEPH, MGST1, SERPINA, SLC25A45, SLC39A11 and UGT1A were imputed from the 1000 Genomes Project and examined for association with INV EOC in white-European subjects. The most significant imputed SNP was rs117729793 in SLC39A11 (per allele, OR = 2.55, 95% CI = 1.5-4.35, p = 5.66x10-4.These results, generated on a large cohort of women, revealed associations between inherited cellular

Common Genetic Variation In Cellular Transport Genes and Epithelial Ovarian Cancer (EOC) Risk

Science.gov (United States)

Chornokur, Ganna; Lin, Hui-Yi; Tyrer, Jonathan P.; Lawrenson, Kate; Dennis, Joe; Amankwah, Ernest K.; Qu, Xiaotao; Tsai, Ya-Yu; Jim, Heather S. L.; Chen, Zhihua; Chen, Ann Y.; Permuth-Wey, Jennifer; Aben, Katja KH.; Anton-Culver, Hoda; Antonenkova, Natalia; Bruinsma, Fiona; Bandera, Elisa V.; Bean, Yukie T.; Beckmann, Matthias W.; Bisogna, Maria; Bjorge, Line; Bogdanova, Natalia; Brinton, Louise A.; Brooks-Wilson, Angela; Bunker, Clareann H.; Butzow, Ralf; Campbell, Ian G.; Carty, Karen; Chang-Claude, Jenny; Cook, Linda S.; Cramer, Daniel W.; Cunningham, Julie M.; Cybulski, Cezary; Dansonka-Mieszkowska, Agnieszka; du Bois, Andreas; Despierre, Evelyn; Dicks, Ed; Doherty, Jennifer A.; Dörk, Thilo; Dürst, Matthias; Easton, Douglas F.; Eccles, Diana M.; Edwards, Robert P.; Ekici, Arif B.; Fasching, Peter A.; Fridley, Brooke L.; Gao, Yu-Tang; Gentry-Maharaj, Aleksandra; Giles, Graham G.; Glasspool, Rosalind; Goodman, Marc T.; Gronwald, Jacek; Harrington, Patricia; Harter, Philipp; Hein, Alexander; Heitz, Florian; Hildebrandt, Michelle A. T.; Hillemanns, Peter; Hogdall, Claus K.; Hogdall, Estrid; Hosono, Satoyo; Jakubowska, Anna; Jensen, Allan; Ji, Bu-Tian; Karlan, Beth Y.; Kelemen, Linda E.; Kellar, Mellissa; Kiemeney, Lambertus A.; Krakstad, Camilla; Kjaer, Susanne K.; Kupryjanczyk, Jolanta; Lambrechts, Diether; Lambrechts, Sandrina; Le, Nhu D.; Lee, Alice W.; Lele, Shashi; Leminen, Arto; Lester, Jenny; Levine, Douglas A.; Liang, Dong; Lim, Boon Kiong; Lissowska, Jolanta; Lu, Karen; Lubinski, Jan; Lundvall, Lene; Massuger, Leon F. A. G.; Matsuo, Keitaro; McGuire, Valerie; McLaughlin, John R.; McNeish, Iain; Menon, Usha; Milne, Roger L.; Modugno, Francesmary; Moysich, Kirsten B.; Ness, Roberta B.; Nevanlinna, Heli; Eilber, Ursula; Odunsi, Kunle; Olson, Sara H.; Orlow, Irene; Orsulic, Sandra; Weber, Rachel Palmieri; Paul, James; Pearce, Celeste L.; Pejovic, Tanja; Pelttari, Liisa M.; Pike, Malcolm C.; Poole, Elizabeth M.; Risch, Harvey A.; Rosen, Barry; Rossing, Mary Anne; Rothstein, Joseph H.; Rudolph, Anja; Runnebaum, Ingo B.; Rzepecka, Iwona K.; Salvesen, Helga B.; Schernhammer, Eva; Schwaab, Ira; Shu, Xiao-Ou; Shvetsov, Yurii B.; Siddiqui, Nadeem; Sieh, Weiva; Song, Honglin; Southey, Melissa C.; Spiewankiewicz, Beata; Sucheston, Lara; Teo, Soo-Hwang; Terry, Kathryn L.; Thompson, Pamela J.; Thomsen, Lotte; Tangen, Ingvild L.; Tworoger, Shelley S.; van Altena, Anne M.; Vierkant, Robert A.; Vergote, Ignace; Walsh, Christine S.; Wang-Gohrke, Shan; Wentzensen, Nicolas; Whittemore, Alice S.; Wicklund, Kristine G.; Wilkens, Lynne R.; Wu, Anna H.; Wu, Xifeng; Woo, Yin-Ling; Yang, Hannah; Zheng, Wei; Ziogas, Argyrios; Hasmad, Hanis N.; Berchuck, Andrew; Iversen, Edwin S.; Schildkraut, Joellen M.; Ramus, Susan J.; Goode, Ellen L.; Monteiro, Alvaro N. A.; Gayther, Simon A.; Narod, Steven A.; Pharoah, Paul D. P.; Sellers, Thomas A.; Phelan, Catherine M.

2015-01-01

Background Defective cellular transport processes can lead to aberrant accumulation of trace elements, iron, small molecules and hormones in the cell, which in turn may promote the formation of reactive oxygen species, promoting DNA damage and aberrant expression of key regulatory cancer genes. As DNA damage and uncontrolled proliferation are hallmarks of cancer, including epithelial ovarian cancer (EOC), we hypothesized that inherited variation in the cellular transport genes contributes to EOC risk. Methods In total, DNA samples were obtained from 14,525 case subjects with invasive EOC and from 23,447 controls from 43 sites in the Ovarian Cancer Association Consortium (OCAC). Two hundred seventy nine SNPs, representing 131 genes, were genotyped using an Illumina Infinium iSelect BeadChip as part of the Collaborative Oncological Gene-environment Study (COGS). SNP analyses were conducted using unconditional logistic regression under a log-additive model, and the FDR q<0.2 was applied to adjust for multiple comparisons. Results The most significant evidence of an association for all invasive cancers combined and for the serous subtype was observed for SNP rs17216603 in the iron transporter gene HEPH (invasive: OR = 0.85, P = 0.00026; serous: OR = 0.81, P = 0.00020); this SNP was also associated with the borderline/low malignant potential (LMP) tumors (P = 0.021). Other genes significantly associated with EOC histological subtypes (p<0.05) included the UGT1A (endometrioid), SLC25A45 (mucinous), SLC39A11 (low malignant potential), and SERPINA7 (clear cell carcinoma). In addition, 1785 SNPs in six genes (HEPH, MGST1, SERPINA, SLC25A45, SLC39A11 and UGT1A) were imputed from the 1000 Genomes Project and examined for association with INV EOC in white-European subjects. The most significant imputed SNP was rs117729793 in SLC39A11 (per allele, OR = 2.55, 95% CI = 1.5-4.35, p = 5.66x10-4). Conclusion These results, generated on a large cohort of women, revealed associations

Investigation of SLC6A4 gene expression in autism spectrum disorders

Directory of Open Access Journals (Sweden)

Elif Funda Şener

2015-06-01

Full Text Available Objective: Autism is defined as a complex neurodevelopmental disorder. Genetics plays a major role in the etiology of autism spectrum disorders (ASD. The role of the serotonin in the development of autism has been widely investigated. SLC6A4 gene (SERT or 5-HT has an important role reuptaking of serotonin. Because of this, our study examined the expression level of SLC6A4 gene in autism patients. Methods: Thirty-four patients (26 male, 8 female who diagnosed as autism firstly according to DSM-V criteria in the Department of child psychiatry, Erciyes University Medical Faculty and healthy 23 controls (16 male, 7 female were enrolled in this study. Total RNA was isolated from peripheral blood samples using TRIzol. Quantitative Real-time PCR (qRT-PCR was performed to detect SLC6A4 gene expression. Results: SLC6A4 gene expression was found statistically significant and low in autism group compared with controls (p=0,027. Conclusion: The low gene expression in the patient group implied that there is an abnormality of serotonin reuptake. According to our results, we suggest that much more studies may be planned with the expression and methylation profile of this gene combined with gene polymorphisms especially affecting the expression in larger sample sizes. J Clin Exp Invest 2015; 6 (2: 165-169

Lack of Association between a 3'UTR VNTR Polymorphism of Dopamine Transporter Gene (SLC6A3) and ADHD in a Brazilian Sample of Adult Patients

Science.gov (United States)

Aperecida da Silva, Maria; Cordeiro, Quirino; Louza, Mario; Vallada, Homero

2011-01-01

Objective: To investigate a possible association between a 3'UTR VNTR polymorphism of the dopamine transporter gene (SLC6A3) and ADHD in a Brazilian sample of adult patients. Method: Study Case-control with 102 ADHD adult outpatients ("DSM-IV" criteria) and 479 healthy controls. The primers' sequence used were: 3'UTR-Forward: 5' TGT GGT…

Intronic deletions in the SLC34A3 gene: A cautionary tale for mutation analysis of hereditary hypophosphatemic rickets with hypercalciuria

OpenAIRE

Ichikawa, Shoji; Tuchman, Shamir; Padgett, Leah R.; Gray, Amie K.; Baluarte, H. Jorge; Econs, Michael J.

2013-01-01

Hereditary hypophosphatemic rickets with hypercalciuria (HHRH) is a rare metabolic disorder, characterized by hypophosphatemia, variable degrees of rickets/osteomalacia, and hypercalciuria secondary to increased serum 1,25-dihydroxyvitamin D [1,25(OH)2D] levels. HHRH is caused by mutations in the SLC34A3 gene, which encodes sodium-phosphate co-transporter type IIc. A 6 ½-year-old female presented with a history of nephrolithiasis. Her metabolic evaluation revealed increased 24- hour urine cal...

Family-Based Association Study Between SLC2A1, HK1, and LEPR Polymorphisms With Myelomeningocele in Chile

Science.gov (United States)

Suazo, José; Castillo, Silvia; Martin, Luz Maria; Rojas, Francisca; Santos, José Luis; Rotter, Karin; Solar, Margarita; Tapia, Eva

2013-01-01

Obese/diabetic mothers present a higher risk to develop offspring with myelomeningocele (MM), evidence supporting the role of energy homeostasis-related genes in neural tube defects. Using polymerase chain reaction–restriction fragment length polymorphism, we have genotyped SLC2A1, HK1, and LEPR single-nucleotide polymorphisms in 105 Chilean patients with MM and their parents in order to evaluate allele–phenotype associations by means of allele/haplotype transmission test (TDT) and parent-of-origin effects. We detected an undertransmission for the SLC2A1 haplotype T-A (rs710218-rs2229682; P = .040), which was not significant when only lower MM (90% of the cases) was analyzed. In addition, the leptin receptor rs1137100 G allele showed a significant increase in the risk of MM for maternal-derived alleles in the whole sample (2.43-fold; P = .038) and in lower MM (3.20-fold; P = .014). Our results support the role of genes involved in energy homeostasis in the risk of developing MM, thus sustaining the hypothesis of diverse pathways and genetic mechanisms acting in the expression of such birth defect. PMID:23427181

Cloning and characterization of the promoter regions from the parent and paralogous creatine transporter genes.

Science.gov (United States)

Ndika, Joseph D T; Lusink, Vera; Beaubrun, Claudine; Kanhai, Warsha; Martinez-Munoz, Cristina; Jakobs, Cornelis; Salomons, Gajja S

2014-01-10

Interconversion between phosphocreatine and creatine, catalyzed by creatine kinase is crucial in the supply of ATP to tissues with high energy demand. Creatine's importance has been established by its use as an ergogenic aid in sport, as well as the development of intellectual disability in patients with congenital creatine deficiency. Creatine biosynthesis is complemented by dietary creatine uptake. Intracellular transport of creatine is carried out by a creatine transporter protein (CT1/CRT/CRTR) encoded by the SLC6A8 gene. Most tissues express this gene, with highest levels detected in skeletal muscle and kidney. There are lower levels of the gene detected in colon, brain, heart, testis and prostate. The mechanism(s) by which this regulation occurs is still poorly understood. A duplicated unprocessed pseudogene of SLC6A8-SLC6A10P has been mapped to chromosome 16p11.2 (contains the entire SLC6A8 gene, plus 2293 bp of 5'flanking sequence and its entire 3'UTR). Expression of SLC6A10P has so far only been shown in human testis and brain. It is still unclear as to what is the function of SLC6A10P. In a patient with autism, a chromosomal breakpoint that intersects the 5'flanking region of SLC6A10P was identified; suggesting that SLC6A10P is a non-coding RNA involved in autism. Our aim was to investigate the presence of cis-acting factor(s) that regulate expression of the creatine transporter, as well as to determine if these factors are functionally conserved upstream of the creatine transporter pseudogene. Via gene-specific PCR, cloning and functional luciferase assays we identified a 1104 bp sequence proximal to the mRNA start site of the SLC6A8 gene with promoter activity in five cell types. The corresponding 5'flanking sequence (1050 bp) on the pseudogene also had promoter activity in all 5 cell lines. Surprisingly the pseudogene promoter was stronger than that of its parent gene in 4 of the cell lines tested. To the best of our knowledge, this is the first

ρ0 Cells Feature De-Ubiquitination of SLC Transporters and Increased Levels and Fluxes of Amino Acids

Directory of Open Access Journals (Sweden)

André Bordinassi Medina

2017-04-01

Full Text Available Solute carrier (SLC transporters are a diverse group of membrane transporter proteins that regulate the cellular flux and distribution of endogenous and xenobiotic compounds. Post-translational modifications (PTMs, such as ubiquitination, have recently emerged as one of the major regulatory mechanisms in protein function and localization. Previously, we showed that SLC amino acid transporters were on average 6-fold de-ubiquitinated and increased amino acid levels were detected in ρ0 cells (lacking mitochondrial DNA, mtDNA compared to parental cells. Here, we elucidated the altered functionality of SLC transporters and their dynamic ubiquitination status by measuring the uptake of several isotopically labeled amino acids in both human osteosarcoma 143B.TK- and ρ0 cells. Our pulse chase analysis indicated that de-ubiquitinated amino acid transporters in ρ0 cells were accompanied by an increased transport rate, which leads to higher levels of amino acids in the cell. Finding SLC transport enhancers is an aim of the pharmaceutical industry in order to compensate for loss of function mutations in these genes. Thus, the ubiquitination status of SLC transporters could be an indicator for their functionality, but evidence for a direct connection between de-ubiquitination and transporter activity has to be further elucidated.

The cyanobacterial bicarbonate transporter BicA: its physiological role and the implications of structural similarities with human SLC26 transporters.

Science.gov (United States)

Price, G Dean; Howitt, Susan M

2011-04-01

The cyanobacterial Na+-dependent HCO3- transporter BicA is a member of the ubiquitous and important SulP/SLC26 family of anion transporters found in eukaryotes and prokaryotes. BicA is an important component of the cyanobacterial CO2 concentrating mechanism, an adaptation that contributes to cyanobacteria being able to achieve an estimated 25% of global primary productivity, largely in the oceans. The human SLC26 members are involved in a range of key cellular functions involving a diverse range of anion transport activities including Cl-/HCO3-, I-/HCO3-, and SO42-/HCO3- exchange; mutations in SLC26 members are known to be associated with debilitating diseases such as Pendred syndrome, chondrodysplasias, and congenital chloride diarrhoea. We have recently experimentally determined the membrane topology of BicA using the phoA-lacZ reporter system and here consider some of the extrapolated implications for topology of the human SLC26 family and the Sultr plant sulphate transporters.

The mammalian phosphate carrier SLC25A3 is a mitochondrial copper transporter required for cytochrome c oxidase biogenesis.

Science.gov (United States)

Boulet, Aren; Vest, Katherine E; Maynard, Margaret K; Gammon, Micah G; Russell, Antoinette C; Mathews, Alexander T; Cole, Shelbie E; Zhu, Xinyu; Phillips, Casey B; Kwong, Jennifer Q; Dodani, Sheel C; Leary, Scot C; Cobine, Paul A

2018-02-09

Copper is required for the activity of cytochrome c oxidase (COX), the terminal electron-accepting complex of the mitochondrial respiratory chain. The likely source of copper used for COX biogenesis is a labile pool found in the mitochondrial matrix. In mammals, the proteins that transport copper across the inner mitochondrial membrane remain unknown. We previously reported that the mitochondrial carrier family protein Pic2 in budding yeast is a copper importer. The closest Pic2 ortholog in mammalian cells is the mitochondrial phosphate carrier SLC25A3. Here, to investigate whether SLC25A3 also transports copper, we manipulated its expression in several murine and human cell lines. SLC25A3 knockdown or deletion consistently resulted in an isolated COX deficiency in these cells, and copper addition to the culture medium suppressed these biochemical defects. Consistent with a conserved role for SLC25A3 in copper transport, its heterologous expression in yeast complemented copper-specific defects observed upon deletion of PIC2 Additionally, assays in Lactococcus lactis and in reconstituted liposomes directly demonstrated that SLC25A3 functions as a copper transporter. Taken together, these data indicate that SLC25A3 can transport copper both in vitro and in vivo . © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

SLC45A2 mutation frequency in Oculocutaneous Albinism Italian patients doesn't differ from other European studies.

Science.gov (United States)

Mauri, Lucia; Barone, Luca; Al Oum, Muna; Del Longo, Alessandra; Piozzi, Elena; Manfredini, Emanuela; Stanzial, Franco; Benedicenti, Francesco; Penco, Silvana; Patrosso, Maria Cristina

2014-01-01

Oculocutaneous Albinism (OCA) is a heterogeneous group of inherited diseases involving hair, skin and eyes. To date, six forms are recognized on the effects of different melanogenesis genes. OCA4 is caused by mutations in SLC45A2 showing a heterogeneous phenotype ranging from white hair, blue irides and nystagmus to brown/black hair, brown irides and no nystagmus. The high clinic variety often leads to misdiagnosis. Our aim is to contribute to OCA4 diagnosis defining SLC45A2 genetic variants in Italian patients with OCA without any TYR, OCA2 and TYRP1 gene defects. After the clinical diagnosis of OCA, all patients received genetic counseling and genetic test. Automatic sequencing of TYR, OCA2, and TYRP1 genes was performed on DNA of 117 albino patients. Multiplex Ligation-dependent Probe Amplification (MLPA) was carried out on TYR and OCA2 genes to increase the mutation rate. SLC45A2 gene sequencing was then executed in the patients with a single mutation in one of the TYR, OCA2, TYRP1 genes and in the patients, which resulted negative at the screening of these genes. SLC45A2 gene analysis was performed in 41 patients and gene alterations were found in 5 patients. Four previously reported SLC45A2 mutations were found: p.G100S, p.W202C, p.A511E and c.986delC, and three novel variants were identified: p.M265L, p.H94D, and c.1156+1G>A. All the alterations have been detected in the group of patients without mutations in the other OCA genes. Three new variants were identified in OCA4 gene; the analysis allowed the classification of a patient previously misdiagnosed as OA1 because of skin and hair pigmentation presence. The molecular defects in SLC45A2 gene represent the 3.4% in this cohort of Italian patients, similar to other Caucasian populations; our data differ from those previously published by an Italian researcher group, obtained on a smaller cohort of patients. © 2013 Elsevier B.V. All rights reserved.

Sodium bicarbonate cotransporter NBCe2 gene variants increase sodium and bicarbonate transport in human renal proximal tubule cells.

Science.gov (United States)

Gildea, John J; Xu, Peng; Kemp, Brandon A; Carlson, Julia M; Tran, Hanh T; Bigler Wang, Dora; Langouët-Astrié, Christophe J; McGrath, Helen E; Carey, Robert M; Jose, Pedro A; Felder, Robin A

2018-01-01

Salt sensitivity of blood pressure affects >30% of the hypertensive and >15% of the normotensive population. Variants of the electrogenic sodium bicarbonate cotransporter NBCe2 gene, SLC4A5, are associated with increased blood pressure in several ethnic groups. SLC4A5 variants are also highly associated with salt sensitivity, independent of hypertension. However, little is known about how NBCe2 contributes to salt sensitivity, although NBCe2 regulates renal tubular sodium bicarbonate transport. We hypothesized that SLC4A5 rs10177833 and rs7571842 increase NBCe2 expression and human renal proximal tubule cell (hRPTC) sodium transport and may be a cause of salt sensitivity of blood pressure. To characterize the hRPTC ion transport of wild-type (WT) and homozygous variants (HV) of SLC4A5. The expressions of NBCe2 mRNA and protein were not different between hRPTCs carrying WT or HV SLC4A5 before or after dopaminergic or angiotensin (II and III) stimulation. However, luminal to basolateral sodium transport, NHE3 protein, and Cl-/HCO3- exchanger activity in hRPTCs were higher in HV than WT SLC4A5. Increasing intracellular sodium enhanced the apical location of NBCe2 in HV hRPTCs (4.24±0.35% to 11.06±1.72% (P<0.05, N = 3, 2-way ANOVA, Holm-Sidak test)) as determined by Total Internal Reflection Fluorescence Microscopy (TIRFM). In hRPTCs isolated from kidney tissue, increasing intracellular sodium enhanced bicarbonate-dependent pH recovery rate and increased NBCe2 mRNA and protein expressions to a greater extent in HV than WT SLC4A5 (+38.00±6.23% vs HV normal salt (P<0.01, N = 4, 2-way ANOVA, Holm-Sidak test)). In hRPTCs isolated from freshly voided urine, bicarbonate-dependent pH recovery was also faster in those from salt-sensitive and carriers of HV SLC4A5 than from salt-resistant and carriers of WT SLC4A5. The faster NBCe2-specific bicarbonate-dependent pH recovery rate in HV SCL4A5 was normalized by SLC4A5- but not SLC4A4-shRNA. The binding of purified hepatocyte

Relationship between ZnT8Ab, the SLC30A8 gene and disease progression in children with newly diagnosed type 1 diabetes

DEFF Research Database (Denmark)

Nielsen, L. B.; Vaziri-Sani, F.; Porksen, S.

2011-01-01

Autoantibodies against the newly established autoantigen in type 1 diabetes, zinc transporter 8, ZnT8, are presented as two types, ZnT8RAb and ZnT8WAb. The rs13266634 variant of the SLC30A8 gene has recently been found to determine the type of ZnT8Ab. The aim of this study was to explore the impact......8 gene is associated with preserved beta-cell function in type 1 diabetes patients. The genetic determination of the rs13266634 variant on the ZnT8Ab specificity is sustained the first 12 months after the diagnosis of type 1 diabetes in a pediatric cohort....

Essential roles of aspartate aminotransferase 1 and vesicular glutamate transporters in β-cell glutamate signaling for incretin-induced insulin secretion.

Directory of Open Access Journals (Sweden)

Naoya Murao

Full Text Available Incretins (GLP-1 and GIP potentiate insulin secretion through cAMP signaling in pancreatic β-cells in a glucose-dependent manner. We recently proposed a mechanistic model of incretin-induced insulin secretion (IIIS that requires two critical processes: 1 generation of cytosolic glutamate through the malate-aspartate (MA shuttle in glucose metabolism and 2 glutamate transport into insulin granules by cAMP signaling to promote insulin granule exocytosis. To directly prove the model, we have established and characterized CRISPR/Cas9-engineered clonal mouse β-cell lines deficient for the genes critical in these two processes: aspartate aminotransferase 1 (AST1, gene symbol Got1, a key enzyme in the MA shuttle, which generates cytosolic glutamate, and the vesicular glutamate transporters (VGLUT1, VGLUT2, and VGLUT3, gene symbol Slc17a7, Slc17a6, and Slc17a8, respectively, which participate in glutamate transport into secretory vesicles. Got1 knockout (KO β-cell lines were defective in cytosolic glutamate production from glucose and showed impaired IIIS. Unexpectedly, different from the previous finding that global Slc17a7 KO mice exhibited impaired IIIS from pancreatic islets, β-cell specific Slc17a7 KO mice showed no significant impairment in IIIS, as assessed by pancreas perfusion experiment. Single Slc17a7 KO β-cell lines also retained IIIS, probably due to compensatory upregulation of Slc17a6. Interestingly, triple KO of Slc17a7, Slc17a6, and Slc17a8 diminished IIIS, which was rescued by exogenously introduced wild-type Slc17a7 or Slc17a6 genes. The present study provides direct evidence for the essential roles of AST1 and VGLUTs in β-cell glutamate signaling for IIIS and also shows the usefulness of the CRISPR/Cas9 system for studying β-cells by simultaneous disruption of multiple genes.

Linking chronic infection and autoimmune diseases: Mycobacterium avium subspecies paratuberculosis, SLC11A1 polymorphisms and type-1 diabetes mellitus.

Directory of Open Access Journals (Sweden)

Daniela Paccagnini

2009-09-01

Full Text Available The etiology of type 1 diabetes mellitus (T1DM is still unknown; numerous studies are performed to unravel the environmental factors involved in triggering the disease. SLC11A1 is a membrane transporter that is expressed in late endosomes of antigen presenting cells involved in the immunopathogenic events leading to T1DM. Mycobacterium avium subsp. paratuberculosis (MAP has been reported to be a possible trigger in the development of T1DM.Fifty nine T1DM patients and 79 healthy controls were genotyped for 9 polymorphisms of SLC11A1 gene, and screened for the presence of MAP by PCR. Differences in genotype frequency were evaluated for both T1DM patients and controls. We found a polymorphism in the SLC11A1 gene (274C/T associated to type 1 diabetic patients and not to controls. The presence of MAP DNA was also significantly associated with T1DM patients and not with controls.The 274C/T SCL11A1 polymorphism was found to be associated with T1DM as well as the presence of MAP DNA in blood. Since MAP persists within macrophages and it is also processed by dendritic cells, further studies are necessary to evaluate if mutant forms of SLC11A1 alter the processing or presentation of MAP antigens triggering thereby an autoimmune response in T1DM patients.

Role of the urate transporter SLC2A9 gene in susceptibility to gout in New Zealand Māori, Pacific Island, and Caucasian case-control sample sets.

Science.gov (United States)

Hollis-Moffatt, Jade E; Xu, Xin; Dalbeth, Nicola; Merriman, Marilyn E; Topless, Ruth; Waddell, Chloe; Gow, Peter J; Harrison, Andrew A; Highton, John; Jones, Peter B B; Stamp, Lisa K; Merriman, Tony R

2009-11-01

To examine the role of genetic variation in the renal urate transporter SLC2A9 in gout in New Zealand sample sets of Māori, Pacific Island, and Caucasian ancestry and to determine if the Māori and Pacific Island samples could be useful for fine-mapping. Patients (n= 56 Māori, 69 Pacific Island, and 131 Caucasian) were recruited from rheumatology outpatient clinics and satisfied the American College of Rheumatology criteria for gout. The control samples comprised 125 Māori subjects, 41 Pacific Island subjects, and 568 Caucasian subjects without arthritis. SLC2A9 single-nucleotide polymorphisms rs16890979 (V253I), rs5028843, rs11942223, and rs12510549 were genotyped (possible etiologic variants in Caucasians). Association of the major allele of rs16890979, rs11942223, and rs5028843 with gout was observed in all sample sets (P = 3.7 x 10(-7), 1.6 x 10(-6), and 7.6 x 10(-5) for rs11942223 in the Māori, Pacific Island, and Caucasian samples, respectively). One 4-marker haplotype (1/1/2/1; more prevalent in the Māori and Pacific Island control samples) was not observed in a single gout case. Our data confirm a role of SLC2A9 in gout susceptibility in a New Zealand Caucasian sample set, with the effect on risk (odds ratio >2.0) greater than previous estimates. We also demonstrate association of SLC2A9 with gout in samples of Māori and Pacific Island ancestry and a consistent pattern of haplotype association. The presence of both alleles of rs16890979 on susceptibility and protective haplotypes in the Māori and Pacific Island sample is evidence against a role for this nonsynonymous variant as the sole etiologic agent. More extensive linkage disequilibrium in Māori and Pacific Island samples suggests that Caucasian samples may be more useful for fine-mapping.

Importance of uncharged polar residues and proline in the proximal two-thirds (Pro107–Ser128 of the highly conserved region of mouse ileal Na+-dependent bile acid transporter, Slc10a2, in transport activity and cellular expression

Directory of Open Access Journals (Sweden)

Saeki Tohru

2013-02-01

Full Text Available Abstract Background SLC10A2-mediated reabsorption of bile acids at the distal end of the ileum is the first step in enterohepatic circulation. Because bile acids act not only as detergents but also as signaling molecules in lipid metabolism and energy production, SLC10A2 is important as the key transporter for understanding the in vivo kinetics of bile acids. SLC10A family members and the homologous genes of various species share a highly conserved region corresponding to Gly104–Pro142 of SLC10A2. The functional importance of this region has not been fully elucidated. Results To elucidate the functional importance of this region, we previously performed mutational analysis of the uncharged polar residues and proline in the distal one-third (Thr130–Pro142 of the highly conserved region in mouse Slc10a2. In this study, proline and uncharged polar residues in the remaining two-thirds of this region in mouse Slc10a2 were subjected to mutational analysis, and taurocholic acid uptake and cell surface localization were examined. Cell surface localization of Slc10a2 is necessary for bile acid absorption. Mutants in which Asp or Leu were substituted for Pro107 (P107N or P107L were abundantly expressed, but their cell surface localization was impaired. The S126A mutant was completely impaired in cellular expression. The T110A and S128A mutants exhibited remarkably enhanced membrane expression. The S112A mutant was properly expressed at the cell surface but transport activity was completely lost. Replacement of Tyr117 with various amino acids resulted in reduced transport activity. The degree of reduction roughly depended on the van der Waals volume of the side chains. Conclusions The functional importance of proline and uncharged polar residues in the highly conserved region of mouse Slc10a2 was determined. This information will contribute to the design of bile acid-conjugated prodrugs for efficient drug delivery or SLC10A2 inhibitors for

Slc3a2 Mediates Branched-Chain Amino-Acid-Dependent Maintenance of Regulatory T Cells

Directory of Open Access Journals (Sweden)

Kayo Ikeda

2017-11-01

Full Text Available Summary: Foxp3+ regulatory T (Treg cells, which suppress immune responses, are highly proliferative in vivo. However, it remains unclear how the active replication of Treg cells is maintained in vivo. Here, we show that branched-chain amino acids (BCAAs, including isoleucine, are required for maintenance of the proliferative state of Treg cells via the amino acid transporter Slc3a2-dependent metabolic reprogramming. Mice fed BCAA-reduced diets showed decreased numbers of Foxp3+ Treg cells with defective in vivo proliferative capacity. Mice lacking Slc3a2 specifically in Foxp3+ Treg cells showed impaired in vivo replication and decreased numbers of Treg cells. Slc3a2-deficient Treg cells showed impaired isoleucine-induced activation of the mTORC1 pathway and an altered metabolic state. Slc3a2 mutant mice did not show an isoleucine-induced increase of Treg cells in vivo and exhibited multi-organ inflammation. Taken together, these findings demonstrate that BCAA controls Treg cell maintenance via Slc3a2-dependent metabolic regulation. : Treg cells regulate excess immune responses and are highly proliferative in vivo. Ikeda et al. find that branched-chain amino acids (BCAAs are essentially required to maintain expansion and the suppressive capacity of Treg cells via Slc3a2 and mTORC1. Keywords: Treg cells, amino acids, immunometabolism, immune regulation, transporter

Effects of dopamine D2 receptor (DRD2) and transporter (SLC6A3) polymorphisms on smoking cue-induced cigarette craving among African-American smokers.

Science.gov (United States)

Erblich, J; Lerman, C; Self, D W; Diaz, G A; Bovbjerg, D H

2005-04-01

Cue-induced craving for addictive substances has long been known to contribute to the problem of persistent addiction in humans. Research in animals over the past decade has solidly established the central role of dopamine in cue-induced craving for addictive substances, including nicotine. Analogous studies in humans, however, are lacking, especially among African-American smokers, who have lower quit rates than Caucasian smokers. Based on the animal literature, the study's objective was to test the hypothesis that smokers carrying specific variants in dopamine-related genes previously associated with risk for addictive behaviors would exhibit heightened levels of cigarette craving following laboratory exposure to cues. To this end, cigarette craving was induced in healthy African-American smokers (n=88) through laboratory exposure to smoking cues. Smokers carrying either the DRD2 (D2 dopamine receptor gene) TaqI A1 RFLP or the SLC6A3 (dopamine transporter gene) 9-repeat VNTR polymorphisms had stronger cue-induced cravings than noncarriers (Ps cue-induced craving in humans, and suggest a possible genetic risk factor for persistent smoking behavior in African-American smokers.

Comprehensive phenotype/genotype analyses of the norepinephrine transporter gene (SLC6A2 in ADHD: relation to maternal smoking during pregnancy.

Directory of Open Access Journals (Sweden)

Geeta A Thakur

Full Text Available Despite strong pharmacological evidence implicating the norepinephrine transporter in ADHD, genetic studies have yielded largely insignificant results. We tested the association between 30 tag SNPs within the SLC6A2 gene and ADHD, with stratification based on maternal smoking during pregnancy, an environmental factor strongly associated with ADHD.Children (6-12 years old diagnosed with ADHD according to DSM-IV criteria were comprehensively evaluated with regard to several behavioral and cognitive dimensions of ADHD as well as response to a fixed dose of methylphenidate (MPH using a double-blind placebo controlled crossover trial. Family-based association tests (FBAT, including categorical and quantitative trait analyses, were conducted in 377 nuclear families.A highly significant association was observed with rs36021 (and linked SNPs in the group where mothers smoked during pregnancy. Association was noted with categorical DSM-IV ADHD diagnosis (Z=3.74, P=0.0002, behavioral assessments by parents (CBCL, P=0.00008, as well as restless-impulsive subscale scores on Conners'-teachers (P=0.006 and parents (P=0.006. In this subgroup, significant association was also observed with cognitive deficits, more specifically sustained attention, spatial working memory, planning, and response inhibition. The risk allele was associated with significant improvement of behavior as measured by research staff (Z=3.28, P=0.001, parents (Z=2.62, P=0.009, as well as evaluation in the simulated academic environment (Z=3.58, P=0.0003.By using maternal smoking during pregnancy to index a putatively more homogeneous group of ADHD, highly significant associations were observed between tag SNPs within SLC6A2 and ADHD diagnosis, behavioral and cognitive measures relevant to ADHD and response to MPH. This comprehensive phenotype/genotype analysis may help to further understand this complex disorder and improve its treatment. Clinical trial registration information - Clinical

Effects of Sodium and Amino Acid Substrate Availability upon the Expression and Stability of the SNAT2 (SLC38A2 Amino Acid Transporter

Directory of Open Access Journals (Sweden)

Thorsten M. Hoffmann

2018-02-01

Full Text Available The SNAT2 (SLC38A2 System A amino acid transporter mediates Na+-coupled cellular uptake of small neutral α-amino acids (AAs and is extensively regulated in response to humoral and nutritional cues. Understanding the basis of such regulation is important given that AA uptake via SNAT2 has been linked to activation of mTORC1; a major controller of many important cellular processes including, for example, mRNA translation, lipid synthesis, and autophagy and whose dysregulation has been implicated in the development of cancer and conditions such as obesity and type 2 diabetes. Extracellular AA withdrawal induces an adaptive upregulation of SNAT2 gene transcription and SNAT2 protein stability but, as yet, the sensing mechanism(s that initiate this response remain poorly understood although interactions between SNAT2 and its substrates may play a vital role. Herein, we have explored how changes in substrate (AA and Na+ availability impact upon the adaptive regulation of SNAT2 in HeLa cells. We show that while AA deprivation induces SNAT2 gene expression, this induction was not apparent if extracellular Na+ was removed during the AA withdrawal period. Furthermore, we show that the increase in SNAT2 protein stability associated with AA withdrawal is selectively repressed by provision of SNAT2 AA substrates (N-methylaminoisobutyric acid and glutamine, but not non-substrates. This stabilization and substrate-induced repression were critically dependent upon the cytoplasmic N-terminal tail of SNAT2 (containing lysyl residues which are putative targets of the ubiquitin-proteasome system, because “grafting” this tail onto SNAT5, a related SLC38 family member that does not exhibit adaptive regulation, confers substrate-induced changes in stability of the SNAT2-5 chimeric transporter. In contrast, expression of SNAT2 in which the N-terminal lysyl residues were mutated to alanine rendered the transporter stable and insensitive to substrate-induced changes

Transport via SLC5A8 with Subsequent Inhibition of Histone Deacetylases HDAC1 and HDAC3 Underlies the Antitumor Activity of 3-Bromopyruvate

Science.gov (United States)

Thangaraju, Muthusamy; Karunakaran, Senthil K.; Itagaki, Shiro; Gopal, Elangovan; Elangovan, Selvakumar; Prasad, Puttur D.; Ganapathy, Vadivel

2009-01-01

Background 3-Bromopyruvate is an alkylating agent with antitumor activity. It is currently believed that blockade of ATP production from glycolysis and mitochondria is the primary mechanism responsible for this antitumor effect. The present studies have uncovered a new and novel mechanism for the antitumor activity of 3-bromopyruvate. Methods Transport of 3-bromopyruvate via SLC5A8, a tumor suppressor and a Na+-coupled electrogenic transporter for short-chain monocarboxylates, was studied using a mammalian cell expression and the Xenopus laevis oocyte expression systems. The effect of 3-bromopyruvate on histone deacetylases (HDACs) was monitored using the lysate of the human breast cancer cell line MCF7 and human recombinant HDAC isoforms as the enzyme sources. Cell viability was monitored by FACS analysis and colony formation assay. Acetylation status of histone H4 was evaluated by Western blot. Results 3-Bromopyruvate is a transportable substrate for SLC5A8, with the transport process being Na+-coupled and electrogenic. MCF7 cells do not express SLC5A8 and are not affected by 3-bromopyruvate. However, when transfected with SLC5A8 or treated with inhibitors of DNA methylation, these cells undergo apoptosis in the presence of 3-bromopyruvate. This cell death is associated with inhibition of HDAC1/HDAC3. Studies with different isoforms of human recombinant HDACs identify HDAC1 and HDAC3 as the targets for 3-bromopyruvate. Conclusions 3-Bromopyruvate is transported into cells actively via the tumor suppressor SLC5A8 and the process is energized by an electrochemical Na+ gradient. Ectopic expression of the transporter in MCF7 cells leads to apoptosis, and the mechanism involves inhibition of HDAC1/HDAC3. PMID:19637353

Slc5a8, a Na+-coupled high-affinity transporter for short-chain fatty acids, is a conditional tumour suppressor in colon that protects against colitis and colon cancer under low-fibre dietary conditions.

Science.gov (United States)

Gurav, Ashish; Sivaprakasam, Sathish; Bhutia, Yangzom D; Boettger, Thomas; Singh, Nagendra; Ganapathy, Vadivel

2015-07-15

Mammalian colon harbours trillions of bacteria under physiological conditions; this symbiosis is made possible because of a tolerized response from the mucosal immune system. The mechanisms underlying this tolerogenic phenomenon remain poorly understood. In the present study we show that Slc5a8 (solute carrier gene family 5a, member 8), a Na(+)-coupled high-affinity transporter in colon for the bacterial fermentation product butyrate, plays a critical role in this process. Among various immune cells in colon, dendritic cells (DCs) are unique not only in their accessibility to luminal contents but also in their ability to induce tolerogenic phenotype in T-cells. We found that DCs exposed to butyrate express the immunosuppressive enzymes indoleamine 2,3-dioxygenase 1 (IDO1) and aldehyde dehydrogenase 1A2 (Aldh1A2), promote conversion of naive T-cells into immunosuppressive forkhead box P3(+) (FoxP3(+)) Tregs (regulatory T-cells) and suppress conversion of naive T-cells into pro-inflammatory interferon (IFN)-γ-producing cells. Slc5a8-null DCs do not induce IDO1 and Aldh1A2 and do not generate Tregs or suppress IFN-γ-producing T-cells in response to butyrate. We also provide in vivo evidence for an obligatory role for Slc5a8 in suppression of IFN-γ-producing T-cells. Furthermore, Slc5a8 protects against colitis and colon cancer under conditions of low-fibre intake but not when dietary fibre intake is optimal. This agrees with the high-affinity nature of the transporter to mediate butyrate entry into cells. We conclude that Slc5a8 is an obligatory link between dietary fibre and mucosal immune system via the bacterial metabolite butyrate and that this transporter is a conditional tumour suppressor in colon linked to dietary fibre content. © 2015 Authors; published by Portland Press Limited.

Tubular urate transporter gene polymorphisms differentiate patients with gout who have normal and decreased urinary uric acid excretion.

Science.gov (United States)

Torres, Rosa J; de Miguel, Eugenio; Bailén, Rebeca; Banegas, José R; Puig, Juan G

2014-09-01

Primary gout has been associated with single-nucleotide polymorphisms (SNP) in several tubular urate transporter genes. No study has assessed the association of reabsorption and secretion urate transporter gene SNP with gout in a single cohort of documented primary patients with gout carefully subclassified as normoexcretors or underexcretors. Three reabsorption SNP (SLC22A12/URAT1, SLC2A9/GLUT9, and SLC22A11/OAT4) and 2 secretion transporter SNP (SLC17A1/NPT1 and ABCG2/BRCP) were studied in 104 patients with primary gout and in 300 control subjects. The patients were subclassified into normoexcretors and underexcretors according to their serum and 24-h urinary uric acid levels under strict conditions of dietary control. Compared with control subjects, patients with gout showed different allele distributions of the 5 SNP analyzed. However, the diagnosis of underexcretor was only positively associated with the presence of the T allele of URAT1 rs11231825, the G allele of GLUT9 rs16890979, and the A allele of ABCG2 rs2231142. The association of the A allele of ABCG2 rs2231142 in normoexcretors was 10 times higher than in underexcretors. The C allele of NPT1 rs1165196 was only significantly associated with gout in patients with normal uric acid excretion. Gout with uric acid underexcretion is associated with transporter gene SNP related mainly to tubular reabsorption, whereas uric acid normoexcretion is associated only with tubular secretion SNP. This finding supports the concept of distinctive mechanisms to account for hyperuricemia in patients with gout with reduced or normal uric acid excretion.

Solute Carrier Family 26 Member a2 (slc26a2 Regulates Otic Development and Hair Cell Survival in Zebrafish.

Directory of Open Access Journals (Sweden)

Fei Liu

Full Text Available Hearing loss is one of the most prevalent human birth defects. Genetic factors contribute to the pathogenesis of deafness. It is estimated that one-third of deafness genes have already been identified. The current work is an attempt to find novel genes relevant to hearing loss using guilt-by-profiling and guilt-by-association bioinformatics analyses of approximately 80 known non-syndromic hereditary hearing loss (NSHL genes. Among the 300 newly identified candidate deafness genes, slc26a2 were selected for functional studies in zebrafish. The slc26a2 gene was knocked down using an antisense morpholino (MO, and significant defects were observed in otolith patterns, semicircular canal morphology, and lateral neuromast distributions in morphants. Loss-of-function defects are caused primarily by apoptosis, and morphants are insensitive to sound stimulation and imbalanced swimming behaviours. Morphant defects were found to be partially rescued by co-injection of human SLC26A2 mRNA. All the results suggest that bioinformatics is capable of predicting new deafness genes and this showed slc26a2 is to be a critical otic gene whose dysfunction may induce hearing impairment.

Genetic moderation of cocaine subjective effects by variation in the TPH1, TPH2, and SLC6A4 serotonin genes.

Science.gov (United States)

Patriquin, Michelle A; Hamon, Sara C; Harding, Mark J; Nielsen, Ellen M; Newton, Thomas F; De La Garza, Richard; Nielsen, David A

2017-10-01

This study investigated variants of tryptophan hydroxylase (TPH)1, TPH2, and SLC6A4 in the moderation of the subjective effects of cocaine. Non-treatment-seeking cocaine-dependent individuals (N=66) were intravenously administered saline and cocaine (40 mg) in a randomized order. Participants self-reported subjective effects of cocaine using a visual analog scale starting before administration of saline or cocaine (-15 min) to up to 20 min after infusion. Self-report ratings on the visual analog scale ranged from 0 (no effect) to 100 (greatest effect). Participants were genotyped for the TPH1 rs1799913, TPH2 rs4290270, and SLC6A4 5-HTTLPR variants. Repeated-measures analysis of covariance was used to examine changes in subjective effect scores over time while controlling for population structure. Participants carrying the TPH1 rs1799913 A allele reported greater subjective response to cocaine for 'stimulated' and 'access' relative to the CC genotype group. Those carrying the TPH2 rs4290270 A allele reported higher 'good effect' and lower 'depressed' effect relative to the TT genotype group. Those carrying the SLC6A4 5-HTTLPR S' allele reported greater 'desire' and 'access' compared with the L'L' genotype group. These findings indicate that TPH1, TPH2, and SLC6A4 variants moderate the subjective effects of cocaine in non-treatment-seeking cocaine-dependent participants.

Language disorder with mild intellectual disability in a child affected by a novel mutation of SLC6A8 gene.

Science.gov (United States)

Battini, R; Chilosi, A M; Casarano, M; Moro, F; Comparini, A; Alessandrì, M G; Leuzzi, V; Tosetti, M; Cioni, G

2011-02-01

We describe the clinical and molecular features of a child harboring a novel mutation in SLC6A8 gene in association with a milder phenotype than other creatine transporter (CT1) deficient patients (OMIM 300352) [1-7]. The mutation c.757 G>C p.G253R in exon 4 of SLC6A8 was hemizygous in the child, aged 6 years and 6 months, who showed mild intellectual disability with severe speech and language delay. His carrier mother had borderline intellectual functioning. Although the neurochemical and biochemical parameters were fully consistent with those reported in the literature for subjects with CT1 deficit, in our patient within a general cognitive disability, a discrepancy between nonverbal and verbal skills was observed, confirming the peculiar vulnerability of language development under brain Cr depletion. Copyright © 2010 Elsevier Inc. All rights reserved.

Association of SLC11A1 gene polymorphism with caprine ...

Indian Academy of Sciences (India)

Navya

2017-01-16

Jan 16, 2017 ... RESEARCH ARTICLE. Evaluation of the ..... Nramp2 (Slc11a2) expressed at the plasma membrane. Blood, 102 ... Received 21 November 2016, in final revised form 11 January 2017; accepted 12 January 2017. Unedited ...

Significance of downregulation of renal organic cation transporter (SLC47A1 in cisplatin-induced proximal tubular injury

Directory of Open Access Journals (Sweden)

Mizuno T

2015-07-01

Full Text Available Tomohiro Mizuno,1–3 Waichi Sato,2,3 Kazuhiro Ishikawa,4 Yuki Terao,1 Kazuo Takahashi,2 Yukihiro Noda,5 Yukio Yuzawa,2 Tadashi Nagamatsu1 1Department of Analytical Pharmacology, Meijo University Faculty of Pharmacy, Nagoya, 2Department of Nephrology, School of Medicine, Fujita Health University, Toyoake, 3Department of Nephrology, Nagoya University School of Medicine, Nagoya, 4Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University Graduate School of Medicine, Nagoya, 5Division of Clinical Sciences and Neuropsychopharmacology, Meijo University Faculty of Pharmacy, Nagoya, Japan Background/aim: To elucidate the mechanism responsible for developing acute kidney injury in patients with diabetes mellitus, we also evaluated the issue of whether advanced glycation endproducts (AGEs influence the expressions of multi antimicrobial extrusion protein (MATE1/SLC47A1 in tubular cells. Materials and methods: To detect changing expression of MATE1/SLC47A1 in dose- and time-dependent manners, human proximal tubular epithelial cells were incubated with AGE-aggregated-human serum albumin. As a function assay for MATE1/SLC47A1, human proximal tubular epithelial cells were incubated with cisplatin or carboplatin. Results: On incubation with AGEs, the expressions of MATE1/SLC47A1 were decreased in tubular cells. In addition, the toxicities of cisplatin were increased in tubular cells that had been pretreated with AGEs. However, the toxicities of carboplatin were smaller than that of cisplatin in proximal tubular epithelial cells. Conclusion: The expression of the MATE1/SLC47A1 is decreased by AGEs, which increases the risk for proximal tubular injury. Keywords: advanced glycation endproducts, cisplatin, SLC47A1, diabetes mellitus, acute kidney injury

Inhibitors of GLUT/SLC2A Enhance the Action of BCNU and Temozolomide against High-Grade Gliomas

Directory of Open Access Journals (Sweden)

Alberto Azzalin

2017-04-01

Full Text Available Glucose transport across glioblastoma membranes plays a crucial role in maintaining the enhanced glycolysis typical of high-grade gliomas and glioblastoma. We tested the ability of two inhibitors of the glucose transporters GLUT/SLC2A superfamily, indinavir (IDV and ritonavir (RTV, and of one inhibitor of the Na/glucose antiporter type 2 (SGLT2/SLC5A2 superfamily, phlorizin (PHZ, in decreasing glucose consumption and cell proliferation of human and murine glioblastoma cells. We found in vitro that RTV, active on at least three different GLUT/SLC2A transporters, was more effective than IDV, a specific inhibitor of GLUT4/SLC2A4, both in decreasing glucose consumption and lactate production and in inhibiting growth of U87MG and Hu197 human glioblastoma cell lines and primary cultures of human glioblastoma. PHZ was inactive on the same cells. Similar results were obtained when cells were grown in adherence or as 3D multicellular tumor spheroids. RTV treatment but not IDV treatment induced AMP-activated protein kinase (AMPKα phosphorylation that paralleled the decrease in glycolytic activity and cell growth. IDV, but not RTV, induced an increase in GLUT1/SLC2A1 whose activity could compensate for the inhibition of GLUT4/SLC2A4 by IDV. RTV and IDV pass poorly the blood brain barrier and are unlikely to reach sufficient liquoral concentrations in vivo to inhibit glioblastoma growth as single agents. Isobologram analysis of the association of RTV or IDV and 1,3-bis(2-chloroethyl-1-nitrosourea (BCNU or 4-methyl-5-oxo-2,3,4,6,8-pentazabicyclo[4.3.0]nona-2,7,9-triene-9-carboxamide (TMZ indicated synergy only with RTV on inhibition of glioblastoma cells. Finally, we tested in vivo the combination of RTV and BCNU on established GL261 tumors. This drug combination increased the overall survival and allowed a five-fold reduction in the dose of BCNU.

Characterization of Organic Anion Transporter 2 (SLC22A7): A Highly Efficient Transporter for Creatinine and Species-Dependent Renal Tubular Expression.

Science.gov (United States)

Shen, Hong; Liu, Tongtong; Morse, Bridget L; Zhao, Yue; Zhang, Yueping; Qiu, Xi; Chen, Cliff; Lewin, Anne C; Wang, Xi-Tao; Liu, Guowen; Christopher, Lisa J; Marathe, Punit; Lai, Yurong

2015-07-01

The contribution of organic anion transporter OAT2 (SLC22A7) to the renal tubular secretion of creatinine and its exact localization in the kidney are reportedly controversial. In the present investigation, the transport of creatinine was assessed in human embryonic kidney (HEK) cells that stably expressed human OAT2 (OAT2-HEK) and isolated human renal proximal tubule cells (HRPTCs). The tubular localization of OAT2 in human, monkey, and rat kidney was characterized. The overexpression of OAT2 significantly enhanced the uptake of creatinine in OAT2-HEK cells. Under physiologic conditions (creatinine concentrations of 41.2 and 123.5 µM), the initial rate of OAT2-mediated creatinine transport was approximately 11-, 80-, and 80-fold higher than OCT2, multidrug and toxin extrusion protein (MATE)1, and MATE2K, respectively, resulting in approximately 37-, 1850-, and 80-fold increase of the intrinsic transport clearance when normalized to the transporter protein concentrations. Creatinine intracellular uptake and transcellular transport in HRPTCs were decreased in the presence of 50 µM bromosulfophthalein and 100 µM indomethacin, which inhibited OAT2 more potently than other known creatinine transporters, OCT2 and multidrug and toxin extrusion proteins MATE1 and MATE2K (IC50: 1.3 µM vs. > 100 µM and 2.1 µM vs. > 200 µM for bromosulfophthalein and indomethacin, respectively) Immunohistochemistry analysis showed that OAT2 protein was localized to both basolateral and apical membranes of human and cynomolgus monkey renal proximal tubules, but appeared only on the apical membrane of rat proximal tubules. Collectively, the findings revealed the important role of OAT2 in renal secretion and possible reabsorption of creatinine and suggested a molecular basis for potential species difference in the transporter handling of creatinine. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

Autosomal-Recessive Intellectual Disability with Cerebellar Atrophy Syndrome Caused by Mutation of the Manganese and Zinc Transporter Gene SLC39A8

Science.gov (United States)

Boycott, Kym M.; Beaulieu, Chandree L.; Kernohan, Kristin D.; Gebril, Ola H.; Mhanni, Aziz; Chudley, Albert E.; Redl, David; Qin, Wen; Hampson, Sarah; Küry, Sébastien; Tetreault, Martine; Puffenberger, Erik G.; Scott, James N.; Bezieau, Stéphane; Reis, André; Uebe, Steffen; Schumacher, Johannes; Hegele, Robert A.; McLeod, D. Ross; Gálvez-Peralta, Marina; Majewski, Jacek; Ramaekers, Vincent T.; Nebert, Daniel W.; Innes, A. Micheil; Parboosingh, Jillian S.; Abou Jamra, Rami

2015-01-01

Manganese (Mn) and zinc (Zn) are essential divalent cations used by cells as protein cofactors; various human studies and animal models have demonstrated the importance of Mn and Zn for development. Here we describe an autosomal-recessive disorder in six individuals from the Hutterite community and in an unrelated Egyptian sibpair; the disorder is characterized by intellectual disability, developmental delay, hypotonia, strabismus, cerebellar atrophy, and variable short stature. Exome sequencing in one affected Hutterite individual and the Egyptian family identified the same homozygous variant, c.112G>C (p.Gly38Arg), affecting a conserved residue of SLC39A8. The affected Hutterite and Egyptian individuals did not share an extended common haplotype, suggesting that the mutation arose independently. SLC39A8 is a member of the solute carrier gene family known to import Mn, Zn, and other divalent cations across the plasma membrane. Evaluation of these two metal ions in the affected individuals revealed variably low levels of Mn and Zn in blood and elevated levels in urine, indicating renal wasting. Our findings identify a human Mn and Zn transporter deficiency syndrome linked to SLC39A8, providing insight into the roles of Mn and Zn homeostasis in human health and development. PMID:26637978

Intramolecular cross-linking in a bacterial homolog of mammalian SLC6 neurotransmitter transporters suggests an evolutionary conserved role of transmembrane segments 7 and 8

DEFF Research Database (Denmark)

Kniazeff, Julie; Loland, Claus Juul; Goldberg, Naomi

2005-01-01

The extracellular concentration of the neurotransmitters dopamine, serotonin, norepinephrine, GABA and glycine is tightly controlled by plasma membrane transporters belonging to the SLC6 gene family. A very large number of putative transport proteins with a remarkable homology to the SLC6...... proximity between TM 7 and 8 in the tertiary structure of TnaT as previously suggested for the mammalian counterparts. Furthermore, the inhibition of uptake upon cross-linking the two cysteines provides indirect support for a conserved conformational role of these transmembrane domains in the transport...

Effect of heat stress on the gene expression of ion transporters/channels in the uterus of laying hens during eggshell formation.

Science.gov (United States)

Bahadoran, Shahab; Dehghani Samani, Amir; Hassanpour, Hossein

2018-01-01

Heat stress is a problem in laying hens as it decreases egg quality by decreasing eggshell mineralization. Heat stress alters gene expression, hence our aim was to investigate effects of heat stress on gene expression of ion transport elements involving in uterine mineralization (TRPV6, CALB1, ITPR3, SCNN1G, SLC4A4, KCNJ15, SLC4A9, and CLCN2) by real time quantitative PCR. Forty 23-week-old White Leghorn laying hens were housed in two rooms. The control group (n = 20) was maintained at 21-23 °C, and the heat stress group (n = 20) was exposed to 36-38 °C for 8 weeks. All parameters of egg quality including egg weight, surface area, volume, and eggshell weight, thickness, ash weight, and calcium content were decreased in the heat stress group compared to the control group (by 26.9%, 32.7%, 44.1%, 38.4%, 31.7%, 39.4%, and 11.1%, respectively). Total plasma calcium was decreased by 13.4%. Levels of ITPR3, SLC4A4, and SLC4A9 transcripts in the uterine lining were decreased in the heat stress group compared to the control group (by 61.4%, 66.1%, and 66.1%, respectively). CALB1 transcript level was increased (by 34.2 fold) in the heat stress group of hens compared to controls. TRPV6, SCNN1G, KCNJ15, and CLCN2 transcript levels did not significantly differ between control and heat stress groups of laying hens. It is concluded that the down-expression of ITPR3, SLC4A4, and SLC4A9 genes may impair transportation of Cl - , HCO 3 - , and Na + in eggshell mineralization during heat stress. Increased CALB1 gene expression may increase resistance of uterine cells to detrimental effects of heat stress.

Loss-of-function mutations in SLC30A8 protect against type 2 diabetes.

Science.gov (United States)

Flannick, Jason; Thorleifsson, Gudmar; Beer, Nicola L; Jacobs, Suzanne B R; Grarup, Niels; Burtt, Noël P; Mahajan, Anubha; Fuchsberger, Christian; Atzmon, Gil; Benediktsson, Rafn; Blangero, John; Bowden, Don W; Brandslund, Ivan; Brosnan, Julia; Burslem, Frank; Chambers, John; Cho, Yoon Shin; Christensen, Cramer; Douglas, Desirée A; Duggirala, Ravindranath; Dymek, Zachary; Farjoun, Yossi; Fennell, Timothy; Fontanillas, Pierre; Forsén, Tom; Gabriel, Stacey; Glaser, Benjamin; Gudbjartsson, Daniel F; Hanis, Craig; Hansen, Torben; Hreidarsson, Astradur B; Hveem, Kristian; Ingelsson, Erik; Isomaa, Bo; Johansson, Stefan; Jørgensen, Torben; Jørgensen, Marit Eika; Kathiresan, Sekar; Kong, Augustine; Kooner, Jaspal; Kravic, Jasmina; Laakso, Markku; Lee, Jong-Young; Lind, Lars; Lindgren, Cecilia M; Linneberg, Allan; Masson, Gisli; Meitinger, Thomas; Mohlke, Karen L; Molven, Anders; Morris, Andrew P; Potluri, Shobha; Rauramaa, Rainer; Ribel-Madsen, Rasmus; Richard, Ann-Marie; Rolph, Tim; Salomaa, Veikko; Segrè, Ayellet V; Skärstrand, Hanna; Steinthorsdottir, Valgerdur; Stringham, Heather M; Sulem, Patrick; Tai, E Shyong; Teo, Yik Ying; Teslovich, Tanya; Thorsteinsdottir, Unnur; Trimmer, Jeff K; Tuomi, Tiinamaija; Tuomilehto, Jaakko; Vaziri-Sani, Fariba; Voight, Benjamin F; Wilson, James G; Boehnke, Michael; McCarthy, Mark I; Njølstad, Pål R; Pedersen, Oluf; Groop, Leif; Cox, David R; Stefansson, Kari; Altshuler, David

2014-04-01

Loss-of-function mutations protective against human disease provide in vivo validation of therapeutic targets, but none have yet been described for type 2 diabetes (T2D). Through sequencing or genotyping of ~150,000 individuals across 5 ancestry groups, we identified 12 rare protein-truncating variants in SLC30A8, which encodes an islet zinc transporter (ZnT8) and harbors a common variant (p.Trp325Arg) associated with T2D risk and glucose and proinsulin levels. Collectively, carriers of protein-truncating variants had 65% reduced T2D risk (P = 1.7 × 10(-6)), and non-diabetic Icelandic carriers of a frameshift variant (p.Lys34Serfs*50) demonstrated reduced glucose levels (-0.17 s.d., P = 4.6 × 10(-4)). The two most common protein-truncating variants (p.Arg138* and p.Lys34Serfs*50) individually associate with T2D protection and encode unstable ZnT8 proteins. Previous functional study of SLC30A8 suggested that reduced zinc transport increases T2D risk, and phenotypic heterogeneity was observed in mouse Slc30a8 knockouts. In contrast, loss-of-function mutations in humans provide strong evidence that SLC30A8 haploinsufficiency protects against T2D, suggesting ZnT8 inhibition as a therapeutic strategy in T2D prevention.

Identification of IGF1, SLC4A4, WWOX, and SFMBT1 as hypertension susceptibility genes in Han Chinese with a genome-wide gene-based association study.

Directory of Open Access Journals (Sweden)

Hsin-Chou Yang

Full Text Available Hypertension is a complex disorder with high prevalence rates all over the world. We conducted the first genome-wide gene-based association scan for hypertension in a Han Chinese population. By analyzing genome-wide single-nucleotide-polymorphism data of 400 matched pairs of young-onset hypertensive patients and normotensive controls genotyped with the Illumina HumanHap550-Duo BeadChip, 100 susceptibility genes for hypertension were identified and also validated with permutation tests. Seventeen of the 100 genes exhibited differential allelic and expression distributions between patient and control groups. These genes provided a good molecular signature for classifying hypertensive patients and normotensive controls. Among the 17 genes, IGF1, SLC4A4, WWOX, and SFMBT1 were not only identified by our gene-based association scan and gene expression analysis but were also replicated by a gene-based association analysis of the Hong Kong Hypertension Study. Moreover, cis-acting expression quantitative trait loci associated with the differentially expressed genes were found and linked to hypertension. IGF1, which encodes insulin-like growth factor 1, is associated with cardiovascular disorders, metabolic syndrome, decreased body weight/size, and changes of insulin levels in mice. SLC4A4, which encodes the electrogenic sodium bicarbonate cotransporter 1, is associated with decreased body weight/size and abnormal ion homeostasis in mice. WWOX, which encodes the WW domain-containing protein, is related to hypoglycemia and hyperphosphatemia. SFMBT1, which encodes the scm-like with four MBT domains protein 1, is a novel hypertension gene. GRB14, TMEM56 and KIAA1797 exhibited highly significant differential allelic and expressed distributions between hypertensive patients and normotensive controls. GRB14 was also found relevant to blood pressure in a previous genetic association study in East Asian populations. TMEM56 and KIAA1797 may be specific to

Lack of association between VNTR polymorphism of dopamine transporter gene (SLC6A3 and schizophrenia in a Brazilian sample Ausência de associação entre o polimorfismo VNTR do gene do transportador de dopamina (SLC6A3 e esquizofrenia em uma população brasileira

Directory of Open Access Journals (Sweden)

Quirino Cordeiro

2004-12-01

Full Text Available A role of dopaminergic dysfunction has been postulated in the aetiology of schizophrenia. We hypothesized that variations in the dopamine transporter gene (SLC6A3 may be associated with schizophrenia. We conducted case-control and family based analysis on the polymorphic SLC6A3 variable number tandem repeat (VNTR in a sample of 220 schizophrenic patients, 226 gender and ethnic matched controls, and 49 additional case-parent trios. No differences were found in allelic or genotypic distributions between cases and controls and no significant transmission distortions from heterozygous parents to schizophrenic offspring were detected. Thus, our results do not support an association of the SLC6A3 VNTR with schizophrenia in our sample.Genes do sistema dopaminérgico são de escolha para a pesquisa de susceptibilidade para a esquizofrenia. Desse modo, possível contribuição do polimorfismo do gene do transportador de dopamina (SLC6A3 no aumento da vulnerabilidade para a esquizofrenia foi investigada no presente estudo. Analisou-se a distribuição do sítio polimórfico do gene do transportador de dopamina (VNTR em uma população de 220 pacientes com esquizofrenia (critério diagnóstico: DSM-IV e comparou-se com a distribuição em uma população controle de 226 indivíduos pareados para sexo e etnia. Nenhuma diferença foi observada na distribuição dos alelos entre casos e controles. O mesmo polimorfismo também foi investigado em uma segunda amostra composta por 49 trios (pais e probando. O resultado também foi negativo. Tais dados não dão suporte para a participação do polimorfismo do gene do transportador de dopamina no aumento de susceptibilidade para esquizofrenia na amostra estudada.

Inorganic phosphorus (Pi) in CSF is a biomarker for SLC20A2-associated idiopathic basal ganglia calcification (IBGC1).

Science.gov (United States)

Hozumi, Isao; Kurita, Hisaka; Ozawa, Kazuhiro; Furuta, Nobuyuki; Inden, Masatoshi; Sekine, Shin-Ichiro; Yamada, Megumi; Hayashi, Yuichi; Kimura, Akio; Inuzuka, Takashi; Seishima, Mitsuru

2018-05-15

Idiopathic basal ganglia calcification (IBGC), also called Fahr's disease or recently primary familial brain calcification (PFBC), is characterized by abnormal deposits of minerals including calcium mainly and phosphate in the brain. Mutations in SLC20A2 (IBGC1 (merged with former IBGC2 and IBGC3)), which encodes PiT-2, a phosphate transporter, is the major cause of IBGC. Recently, Slc20a2-KO mice have been showed to have elevated levels of inorganic phosphorus (Pi) in cerebrospinal fluid (CSF); however, CSF Pi levels in patients with IBGC have not been fully examined. We investigated the cases of 29 patients with IBGC including six patients with SLC20A2 mutation and three patients with PDGFB mutation, and 13 controls. The levels of sodium (Na), potassium (K), chloride (Cl), calcium (Ca), and Pi in sera and CSF were determined by potentiometry and colorimetry. Moreover, clinical manifestations were investigated in the IBGC patients with high Pi levels in CSF. The study revealed that the average level of Pi in the CSF of the total group of patients with IBGC is significantly higher than that of the control group, and the levels of Pi in CSF of the IBGC patients with SLC20A2 mutations are significantly higher than those of the IBGC patients with PDGFB mutations, the other IBGC patients and controls. Results of this study suggest that the levels of CSF Pi will be a good biomarker for IBGC1. Copyright © 2018 Elsevier B.V. All rights reserved.

Molecular Etiology of Hearing Impairment in Inner Mongolia: mutations in SLC26A4 gene and relevant phenotype analysis

Directory of Open Access Journals (Sweden)

Wu Bailin

2008-11-01

Full Text Available Abstract Background The molecular etiology of hearing impairment in Chinese has not been thoroughly investigated. Study of GJB2 gene revealed that 30.4% of the patients with hearing loss in Inner Mongolia carried GJB2 mutations. The SLC26A4 gene mutations and relevant phenotype are analyzed in this study. Methods One hundred and thirty-five deaf patients were included. The coding exons of SLC26A4 gene were sequence analyzed in 111 patients, not including 22 patients carrying bi-allelic GJB2 mutations or one patient carrying a known GJB2 dominant mutation as well as one patient with mtDNA 1555A>G mutation. All patients with SLC26A4 mutations or variants were subjected to high resolution temporal bone CT scan and those with confirmed enlarged vestibular aqueduct and/or other inner ear malformation were then given further ultrasound scan of thyroid and thyroid hormone assays. Results Twenty-six patients (19.26%, 26/135 were found carrying SLC26A4 mutation. Among them, 17 patients with bi-allelic SLC26A4 mutations were all confirmed to have EVA or other inner ear malformation by CT scan. Nine patients were heterozygous for one SLC26A4 mutation, including 3 confirmed to be EVA or EVA and Mondini dysplasia by CT scan. The most common mutation, IVS7-2A>G, accounted for 58.14% (25/43 of all SLC26A4 mutant alleles. The shape and function of thyroid were confirmed to be normal by thyroid ultrasound scan and thyroid hormone assays in 19 of the 20 patients with EVA or other inner ear malformation except one who had cystoid change in the right side of thyroid. No Pendred syndrome was diagnosed. Conclusion In Inner Mongolia, China, mutations in SLC26A4 gene account for about 12.6% (17/135 of the patients with hearing loss. Together with GJB2 (23/135, SLC26A4 are the two most commonly mutated genes causing deafness in this region. Pendred syndrome is not detected in this deaf population. We established a new strategy that detects SLC26A4 mutations prior to the

Molecular Etiology of Hearing Impairment in Inner Mongolia: mutations in SLC26A4 gene and relevant phenotype analysis

Science.gov (United States)

Dai, Pu; Yuan, Yongyi; Huang, Deliang; Zhu, Xiuhui; Yu, Fei; Kang, Dongyang; Yuan, Huijun; Wu, Bailin; Han, Dongyi; Wong, Lee-Jun C

2008-01-01

Background The molecular etiology of hearing impairment in Chinese has not been thoroughly investigated. Study of GJB2 gene revealed that 30.4% of the patients with hearing loss in Inner Mongolia carried GJB2 mutations. The SLC26A4 gene mutations and relevant phenotype are analyzed in this study. Methods One hundred and thirty-five deaf patients were included. The coding exons of SLC26A4 gene were sequence analyzed in 111 patients, not including 22 patients carrying bi-allelic GJB2 mutations or one patient carrying a known GJB2 dominant mutation as well as one patient with mtDNA 1555A>G mutation. All patients with SLC26A4 mutations or variants were subjected to high resolution temporal bone CT scan and those with confirmed enlarged vestibular aqueduct and/or other inner ear malformation were then given further ultrasound scan of thyroid and thyroid hormone assays. Results Twenty-six patients (19.26%, 26/135) were found carrying SLC26A4 mutation. Among them, 17 patients with bi-allelic SLC26A4 mutations were all confirmed to have EVA or other inner ear malformation by CT scan. Nine patients were heterozygous for one SLC26A4 mutation, including 3 confirmed to be EVA or EVA and Mondini dysplasia by CT scan. The most common mutation, IVS7-2A>G, accounted for 58.14% (25/43) of all SLC26A4 mutant alleles. The shape and function of thyroid were confirmed to be normal by thyroid ultrasound scan and thyroid hormone assays in 19 of the 20 patients with EVA or other inner ear malformation except one who had cystoid change in the right side of thyroid. No Pendred syndrome was diagnosed. Conclusion In Inner Mongolia, China, mutations in SLC26A4 gene account for about 12.6% (17/135) of the patients with hearing loss. Together with GJB2 (23/135), SLC26A4 are the two most commonly mutated genes causing deafness in this region. Pendred syndrome is not detected in this deaf population. We established a new strategy that detects SLC26A4 mutations prior to the temporal bone CT scan to

Cation-Coupled Bicarbonate Transporters

OpenAIRE

Aalkjaer, Christian; Boedtkjer, Ebbe; Choi, Inyeong; Lee, Soojung

2014-01-01

Cation-coupled HCO3− transport was initially identified in the mid-1970s when pioneering studies showed that acid extrusion from cells is stimulated by CO2/HCO3− and associated with Na+ and Cl− movement. The first Na+-coupled bicarbonate transporter (NCBT) was expression-cloned in the late 1990s. There are currently five mammalian NCBTs in the SLC4-family: the electrogenic Na,HCO3-cotransporters NBCe1 and NBCe2 (SLC4A4 and SLC4A5 gene products); the electroneutral Na,HCO3-cotransporter NBCn1 ...

SLC1 and SLC4 encode partially redundant acyl-coenzyme A 1-acylglycerol-3-phosphate O-acyltransferases of budding yeast

DEFF Research Database (Denmark)

Benghezal, Mohammed; Roubaty, Carole; Veepuri, Vijayanath

2007-01-01

Phosphatidic acid is the intermediate, from which all glycerophospholipids are synthesized. In yeast, it is generated from lysophosphatidic acid, which is acylated by Slc1p, an sn-2-specific, acyl-coenzyme A-dependent 1-acylglycerol-3-phosphate O-acyltransferase. Deletion of SLC1 is not lethal...

Hypotonic activation of the myo-inositol transporter SLC5A3 in HEK293 cells probed by cell volumetry, confocal and super-resolution microscopy.

Directory of Open Access Journals (Sweden)

Joseph Andronic

Full Text Available Swelling-activated pathways for myo-inositol, one of the most abundant organic osmolytes in mammalian cells, have not yet been identified. The present study explores the SLC5A3 protein as a possible transporter of myo-inositol in hyponically swollen HEK293 cells. To address this issue, we examined the relationship between the hypotonicity-induced changes in plasma membrane permeability to myo-inositol P ino [m/s] and expression/localization of SLC5A3. P ino values were determined by cell volumetry over a wide tonicity range (100-275 mOsm in myo-inositol-substituted solutions. While being negligible under mild hypotonicity (200-275 mOsm, P ino grew rapidly at osmolalities below 200 mOsm to reach a maximum of ∼ 3 nm/s at 100-125 mOsm, as indicated by fast cell swelling due to myo-inositol influx. The increase in P ino resulted most likely from the hypotonicity-mediated incorporation of cytosolic SLC5A3 into the plasma membrane, as revealed by confocal fluorescence microscopy of cells expressing EGFP-tagged SLC5A3 and super-resolution imaging of immunostained SLC5A3 by direct stochastic optical reconstruction microscopy (dSTORM. dSTORM in hypotonic cells revealed a surface density of membrane-associated SLC5A3 proteins of 200-2000 localizations/μm2. Assuming SLC5A3 to be the major path for myo-inositol, a turnover rate of 80-800 myo-inositol molecules per second for a single transporter protein was estimated from combined volumetric and dSTORM data. Hypotonic stress also caused a significant upregulation of SLC5A3 gene expression as detected by semiquantitative RT-PCR and Western blot analysis. In summary, our data provide first evidence for swelling-mediated activation of SLC5A3 thus suggesting a functional role of this transporter in hypotonic volume regulation of mammalian cells.

The cataract and glucosuria associated monocarboxylate transporter MCT12 is a new creatine transporter

Science.gov (United States)

Abplanalp, Jeannette; Laczko, Endre; Philp, Nancy J.; Neidhardt, John; Zuercher, Jurian; Braun, Philipp; Schorderet, Daniel F.; Munier, Francis L.; Verrey, François; Berger, Wolfgang; Camargo, Simone M.R.; Kloeckener-Gruissem, Barbara

2013-01-01

Creatine transport has been assigned to creatine transporter 1 (CRT1), encoded by mental retardation associated SLC6A8. Here, we identified a second creatine transporter (CRT2) known as monocarboxylate transporter 12 (MCT12), encoded by the cataract and glucosuria associated gene SLC16A12. A non-synonymous alteration in MCT12 (p.G407S) found in a patient with age-related cataract (ARC) leads to a significant reduction of creatine transport. Furthermore, Slc16a12 knockout (KO) rats have elevated creatine levels in urine. Transport activity and expression characteristics of the two creatine transporters are distinct. CRT2 (MCT12)-mediated uptake of creatine was not sensitive to sodium and chloride ions or creatine biosynthesis precursors, breakdown product creatinine or creatine phosphate. Increasing pH correlated with increased creatine uptake. Michaelis–Menten kinetics yielded a Vmax of 838.8 pmol/h/oocyte and a Km of 567.4 µm. Relative expression in various human tissues supports the distinct mutation-associated phenotypes of the two transporters. SLC6A8 was predominantly found in brain, heart and muscle, while SLC16A12 was more abundant in kidney and retina. In the lens, the two transcripts were found at comparable levels. We discuss the distinct, but possibly synergistic functions of the two creatine transporters. Our findings infer potential preventive power of creatine supplementation against the most prominent age-related vision impaired condition. PMID:23578822

SLC26A4 gene copy number variations in Chinese patients with non-syndromic enlarged vestibular aqueduct

Directory of Open Access Journals (Sweden)

Zhao Jiandong

2012-05-01

Full Text Available Abstract Background Many patients with enlarged vestibular aqueduct (EVA have either only one allelic mutant of the SLC26A4 gene or lack any detectable mutation. In this study, multiplex ligation-dependent probe amplification (MLPA was used to screen for copy number variations (CNVs of SLC26A4 and to reveal the pathogenic mechanisms of non-syndromic EVA (NSEVA. Methods Between January 2003 and March 2010, 923 Chinese patients (481 males, 442 females with NSEVA were recruited. Among these, 68 patients (7.4% were found to carry only one mutant allele of SLC26A4 and 39 patients (4.2% lacked any detectable mutation in SLC26A4; these 107 patients without double mutant alleles were assigned to the patient group. Possible copy number variations in SLC26A4 were detected by SALSA MLPA. Results Using GeneMapper, no significant difference was observed between the groups, as compared with the standard probe provided in the assay. The results of the capillary electrophoresis showed no significant difference between the patients and controls. Conclusion Our results suggest that CNVs and the exon deletion in SLC26A4 are not important factors in NSEVA. However, it would be premature to conclude that CNVs have no role in EVA. Genome-wide studies to explore CNVs within non-coding regions of the SLC26A4 gene and neighboring regions are warranted, to elucidate their roles in NSEVA etiology.

Exonal deletion of SLC24A4 causes hypomaturation amelogenesis imperfecta.

Science.gov (United States)

Seymen, F; Lee, K-E; Tran Le, C G; Yildirim, M; Gencay, K; Lee, Z H; Kim, J-W

2014-04-01

Amelogenesis imperfecta is a heterogeneous group of genetic conditions affecting enamel formation. Recently, mutations in solute carrier family 24 member 4 (SLC24A4) have been identified to cause autosomal recessive hypomaturation amelogenesis imperfecta. We recruited a consanguineous family with hypomaturation amelogenesis imperfecta with generalized brown discoloration. Sequencing of the candidate genes identified a 10-kb deletion, including exons 15, 16, and most of the last exon of the SLC24A4 gene. Interestingly, this deletion was caused by homologous recombination between two 354-bp-long homologous sequences located in intron 14 and the 3' UTR. This is the first report of exonal deletion in SLC24A4 providing confirmatory evidence that the function of SLC24A4 in calcium transport has a crucial role in the maturation stage of amelogenesis.

[ROLE OF SLC2A9 AND ABCG2 GENE POLYMORPHISMS IN ORIGIN OF HYPERURICEMIA AND GOUT].

Science.gov (United States)

Fadieieva, A; Prystupa, L; Pogorelova, O; Kirichenko, N; Dudchenko, I

2016-03-01

The polymorphisms V253I, Q126X, Q141K of SLC2A9 and ABCG2 genes were characterized. GCA и GTC haplotypes of Q126X and Q141K variants can be predictors of gout. The relationship of these polymorphisms with hyperuricaemia according to gender, metabolic syndrome components, with the response to allopurinol was analyzed. It has been established that Q141K polymorphism can directly modulate BCRP-mediated allopurinol and oxypurinol efflux, the K allele is associated with a lower reduction in serum uric acid in response to allopurinol treatment.

Deletion of the betaine-GABA transporter (BGT1; slc6a12) gene does not affect seizure thresholds of adult mice

DEFF Research Database (Denmark)

Lehre, A C; Rowley, N M; Zhou, Y

2011-01-01

of the GAT1 by the clinically available anti-epileptic drug tiagabine has been an effective strategy for the treatment of some patients with partial seizures. Recently, the investigational drug EF1502, which inhibits both GAT1 and BGT1, was found to exert an anti-convulsant action synergistic...... to that of tiagabine, supposedly due to inhibition of BGT1. The present study addresses the role of BGT1 in seizure control and the effect of EF1502 by developing and exploring a new mouse line lacking exons 3-5 of the BGT1 (slc6a12) gene. The deletion of this sequence abolishes the expression of BGT1 mRNA. However......, homozygous BGT1-deficient mice have normal development and show seizure susceptibility indistinguishable from that in wild-type mice in a variety of seizure threshold models including: corneal kindling, the minimal clonic and minimal tonic extension seizure threshold tests, the 6Hz seizure threshold test...

The blood-brain barrier fatty acid transport protein 1 (FATP1/SLC27A1) supplies docosahexaenoic acid to the brain, and insulin facilitates transport.

Science.gov (United States)

Ochiai, Yusuke; Uchida, Yasuo; Ohtsuki, Sumio; Tachikawa, Masanori; Aizawa, Sanshiro; Terasaki, Tetsuya

2017-05-01

We purposed to clarify the contribution of fatty acid transport protein 1 (FATP1/SLC 27A1) to the supply of docosahexaenoic acid (DHA) to the brain across the blood-brain barrier in this study. Transport experiments showed that the uptake rate of [ 14 C]-DHA in human FATP1-expressing HEK293 cells was significantly greater than that in empty vector-transfected (mock) HEK293 cells. The steady-state intracellular DHA concentration was nearly 2-fold smaller in FATP1-expressing than in mock cells, suggesting that FATP1 works as not only an influx, but also an efflux transporter for DHA. [ 14 C]-DHA uptake by a human cerebral microvascular endothelial cell line (hCMEC/D3) increased in a time-dependent manner, and was inhibited by unlabeled DHA and a known FATP1 substrate, oleic acid. Knock-down of FATP1 in hCMEC/D3 cells with specific siRNA showed that FATP1-mediated uptake accounts for 59.2-73.0% of total [ 14 C]-DHA uptake by the cells. Insulin treatment for 30 min induced translocation of FATP1 protein to the plasma membrane in hCMEC/D3 cells and enhanced [ 14 C]-DHA uptake. Immunohistochemical analysis of mouse brain sections showed that FATP1 protein is preferentially localized at the basal membrane of brain microvessel endothelial cells. We found that two neuroprotective substances, taurine and biotin, in addition to DHA, undergo FATP1-mediated efflux. Overall, our results suggest that FATP1 localized at the basal membrane of brain microvessels contributes to the transport of DHA, taurine and biotin into the brain, and insulin rapidly increases DHA supply to the brain by promoting translocation of FATP1 to the membrane. Read the Editorial Comment for this article on page 324. © 2016 International Society for Neurochemistry.

Human Sodium Phosphate Transporter 4 (hNPT4/SLC17A3) as a Common Renal Secretory Pathway for Drugs and Urate*

Science.gov (United States)

Jutabha, Promsuk; Anzai, Naohiko; Kitamura, Kenichiro; Taniguchi, Atsuo; Kaneko, Shuji; Yan, Kunimasa; Yamada, Hideomi; Shimada, Hidetaka; Kimura, Toru; Katada, Tomohisa; Fukutomi, Toshiyuki; Tomita, Kimio; Urano, Wako; Yamanaka, Hisashi; Seki, George; Fujita, Toshiro; Moriyama, Yoshinori; Yamada, Akira; Uchida, Shunya; Wempe, Michael F.; Endou, Hitoshi; Sakurai, Hiroyuki

2010-01-01

The evolutionary loss of hepatic urate oxidase (uricase) has resulted in humans with elevated serum uric acid (urate). Uricase loss may have been beneficial to early primate survival. However, an elevated serum urate has predisposed man to hyperuricemia, a metabolic disturbance leading to gout, hypertension, and various cardiovascular diseases. Human serum urate levels are largely determined by urate reabsorption and secretion in the kidney. Renal urate reabsorption is controlled via two proximal tubular urate transporters: apical URAT1 (SLC22A12) and basolateral URATv1/GLUT9 (SLC2A9). In contrast, the molecular mechanism(s) for renal urate secretion remain unknown. In this report, we demonstrate that an orphan transporter hNPT4 (human sodium phosphate transporter 4; SLC17A3) was a multispecific organic anion efflux transporter expressed in the kidneys and liver. hNPT4 was localized at the apical side of renal tubules and functioned as a voltage-driven urate transporter. Furthermore, loop diuretics, such as furosemide and bumetanide, substantially interacted with hNPT4. Thus, this protein is likely to act as a common secretion route for both drugs and may play an important role in diuretics-induced hyperuricemia. The in vivo role of hNPT4 was suggested by two hyperuricemia patients with missense mutations in SLC17A3. These mutated versions of hNPT4 exhibited reduced urate efflux when they were expressed in Xenopus oocytes. Our findings will complete a model of urate secretion in the renal tubular cell, where intracellular urate taken up via OAT1 and/or OAT3 from the blood exits from the cell into the lumen via hNPT4. PMID:20810651

Overexpression of monocarboxylate transporter-1 (Slc16a1) in mouse pancreatic ß-cells leads to relative hyperinsulinism during exercise

DEFF Research Database (Denmark)

Pullen, Timothy J; Sylow, Lykke; Sun, Gao

2012-01-01

Exercise-induced hyperinsulinism (EIHI) is an autosomal dominant disorder characterized by inappropriate insulin secretion in response to vigorous physical exercise or pyruvate injection. Activating mutations in the monocarboxylate transporter-1 (MCT1, SLC16A1) promoter have been linked to EIHI....... Expression of this pyruvate transporter is specifically repressed (disallowed) in pancreatic ß-cells, despite nearly universal expression across other tissues. It has been impossible to determine, however, whether EIHI mutations cause MCT1 expression in patient ß-cells. The hypothesis that MCT1 expression...... in ß-cells is sufficient to cause EIHI by allowing entry of pyruvate and triggering insulin secretion thus remains unproven. Therefore, we generated a transgenic mouse capable of doxycycline-induced, ß-cell-specific overexpression of MCT1 to test this model directly. MCT1 expression caused isolated...

Intronic deletions in the SLC34A3 gene: A cautionary tale for mutation analysis of hereditary hypophosphatemic rickets with hypercalciuria

Science.gov (United States)

Ichikawa, Shoji; Tuchman, Shamir; Padgett, Leah R.; Gray, Amie K.; Baluarte, H. Jorge; Econs, Michael J.

2013-01-01

Hereditary hypophosphatemic rickets with hypercalciuria (HHRH) is a rare metabolic disorder, characterized by hypophosphatemia, variable degrees of rickets/osteomalacia, and hypercalciuria secondary to increased serum 1,25-dihydroxyvitamin D [1,25(OH)2D] levels. HHRH is caused by mutations in the SLC34A3 gene, which encodes sodium-phosphate co-transporter type IIc. A 6 ½-year-old female presented with a history of nephrolithiasis. Her metabolic evaluation revealed increased 24- hour urine calcium excretion with high serum calcium, low intact parathyroid hormone (PTH) levels, and elevated 1,25(OH)2D level. In addition, the patient had low to low-normal serum phosphorus with high urine phosphorus. The patient had normal stature; without rachitic or boney deformities or a history of fractures. Genetic analysis of SLC34A3 revealed the patient to be a compound heterozygote for a novel single base pair deletion in exon 12 (c.1304delG) and 30-base pair deletion in intron 6 (g.1440–1469del). The single-base pair mutation causes a frameshift, which results in premature stop codon. The intronic deletion is likely caused by misalignment of the 4-basepair homologous repeats and results in the truncation of an already small intron to 63 bp, which would impair proper RNA splicing of the intron. This is the fourth unique intronic deletion identified in patients with HHRH, suggesting the frequent occurrence of sequence misalignments in SLC34A3 and the importance of screening introns in patients with HHRH. PMID:24176905

Variation in the SLC23A1 gene does not influence cardiometabolic outcomes to the extent expected given its association with l-ascorbic acid 1 2 3 4

OpenAIRE

Wade, Kaitlin H; Forouhi, Nita G; Cook, Derek G; Johnson, Paul; McConnachie, Alex; Morris, Richard W; Rodriguez, Santiago; Ye, Zheng; Ebrahim, Shah; Padmanabhan, Sandosh; Watt, Graham; Bruckdorfer, K Richard; Wareham, Nick J; Whincup, Peter H; Chanock, Stephen

2014-01-01

Background: Observational studies showed that circulating l-ascorbic acid (vitamin C) is inversely associated with cardiometabolic traits. However, these studies were susceptible to confounding and reverse causation.\\ud \\ud Objectives:We assessed the relation between l-ascorbic acid and 10 cardiometabolic traits by using a single nucleotide polymorphism in the solute carrier family 23 member 1 (SLC23A1) gene (rs33972313) associated with circulating l-ascorbic acid concentrations. The observed...

Organic anion and cation SLC22 "drug" transporter (Oat1, Oat3, and Oct1 regulation during development and maturation of the kidney proximal tubule.

Directory of Open Access Journals (Sweden)

Thomas F Gallegos

Full Text Available Proper physiological function in the pre- and post-natal proximal tubule of the kidney depends upon the acquisition of selective permeability, apical-basolateral epithelial polarity and the expression of key transporters, including those involved in metabolite, toxin and drug handling. Particularly important are the SLC22 family of transporters, including the organic anion transporters Oat1 (originally identified as NKT and Oat3 as well as the organic cation transporter Oct1. In ex vivo cultures of metanephric mesenchyme (MM; the embryonic progenitor tissue of the nephron Oat function was evident before completion of nephron segmentation and corresponded with the maturation of tight junctions as measured biochemically by detergent extractability of the tight junction protein, ZO-1. Examination of available time series microarray data sets in the context of development and differentiation of the proximal tubule (derived from both in vivo and in vitro/ex vivo developing nephrons allowed for correlation of gene expression data to biochemically and functionally defined states of development. This bioinformatic analysis yielded a network of genes with connectivity biased toward Hnf4α (but including Hnf1α, hyaluronic acid-CD44, and notch pathways. Intriguingly, the Oat1 and Oat3 genes were found to have strong temporal co-expression with Hnf4α in the cultured MM supporting the notion of some connection between the transporters and this transcription factor. Taken together with the ChIP-qPCR finding that Hnf4α occupies Oat1, Oat3, and Oct1 proximal promoters in the in vivo differentiating rat kidney, the data suggest a network of genes with Hnf4α at its center plays a role in regulating the terminal differentiation and capacity for drug and toxin handling by the nascent proximal tubule of the kidney.

Organic cation transporter 2 (SLC22A2), a low-affinity and high-capacity choline transporter, is preferentially enriched on synaptic vesicles in cholinergic neurons.

Science.gov (United States)

Nakata, T; Matsui, T; Kobayashi, K; Kobayashi, Y; Anzai, N

2013-11-12

Organic cation transporters (OCTs) are expressed mainly in the kidney and liver. OCTs transport intrinsic organic cations, including monoamine, dopamine, serotonine and choline, across the plasma membrane. Here, we demonstrate that OCT2 (SLC22A2) is expressed in cholinergic neurons, motoneurons in the anterior horn of the spinal cord, and is implicated in acetylcholine (Ach) recycling in presynaptic terminals. Application of rabbit anti-peptide antibody revealed that OCT2 was expressed in the anterior horn of the spinal cord. Double immunostaining of muscle sections with anti-OCT2 and alpha-bungarotoxin (BTX) revealed that OCT2 was localized in the neuromuscular junctions (NMJs). Immunoelectron microscopy revealed that OCT2 was localized both in synaptic vesicles (SVs) in presynaptic terminals around the motoneurons (C-terminals) and in SVs in nerve terminals in NMJs. The similarity in the distribution of OCT2 in cholinergic neurons and that of vesicular acetyl choline transporter (VAchT), and the fact that OCT2 can transport choline suggest that OCT2 could work as a low-affinity and high-capacity choline transporter at presynaptic terminals in cholinergic neurons in a firing-dependent manner. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

SLC39A8 Deficiency: A Disorder of Manganese Transport and Glycosylation.

Science.gov (United States)

Park, Julien H; Hogrebe, Max; Grüneberg, Marianne; DuChesne, Ingrid; von der Heiden, Ava L; Reunert, Janine; Schlingmann, Karl P; Boycott, Kym M; Beaulieu, Chandree L; Mhanni, Aziz A; Innes, A Micheil; Hörtnagel, Konstanze; Biskup, Saskia; Gleixner, Eva M; Kurlemann, Gerhard; Fiedler, Barbara; Omran, Heymut; Rutsch, Frank; Wada, Yoshinao; Tsiakas, Konstantinos; Santer, René; Nebert, Daniel W; Rust, Stephan; Marquardt, Thorsten

2015-12-03

SLC39A8 is a membrane transporter responsible for manganese uptake into the cell. Via whole-exome sequencing, we studied a child that presented with cranial asymmetry, severe infantile spasms with hypsarrhythmia, and dysproportionate dwarfism. Analysis of transferrin glycosylation revealed severe dysglycosylation corresponding to a type II congenital disorder of glycosylation (CDG) and the blood manganese levels were below the detection limit. The variants c.112G>C (p.Gly38Arg) and c.1019T>A (p.Ile340Asn) were identified in SLC39A8. A second individual with the variants c.97G>A (p.Val33Met) and c.1004G>C (p.Ser335Thr) on the paternal allele and c.610G>T (p.Gly204Cys) on the maternal allele was identified among a group of unresolved case subjects with CDG. These data demonstrate that variants in SLC39A8 impair the function of manganese-dependent enzymes, most notably β-1,4-galactosyltransferase, a Golgi enzyme essential for biosynthesis of the carbohydrate part of glycoproteins. Impaired galactosylation leads to a severe disorder with deformed skull, severe seizures, short limbs, profound psychomotor retardation, and hearing loss. Oral galactose supplementation is a treatment option and results in complete normalization of glycosylation. SLC39A8 deficiency links a trace element deficiency with inherited glycosylation disorders. Copyright © 2015 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

The gene expression of the neuronal protein, SLC38A9, changes in mouse brain after in vivo starvation and high-fat diet.

Directory of Open Access Journals (Sweden)

Sofie V Hellsten

Full Text Available SLC38A9 is characterized as a lysosomal component of the amino acid sensing Ragulator-RAG GTPase complex, controlling the mechanistic target of rapamycin complex 1 (mTORC1. Here, immunohistochemistry was used to map SLC38A9 in mouse brain and staining was detected throughout the brain, in cortex, hypothalamus, thalamus, hippocampus, brainstem and cerebellum. More specifically, immunostaining was found in areas known to be involved in amino acid sensing and signaling pathways e.g. piriform cortex and hypothalamus. SLC38A9 immunoreactivity co-localized with both GABAergic and glutamatergic neurons, but not with astrocytes. SLC38A9 play a key role in the mTORC1 pathway, and therefore we performed in vivo starvation and high-fat diet studies, to measure gene expression alterations in specific brain tissues and in larger brain regions. Following starvation, Slc38a9 was upregulated in brainstem and cortex, and in anterior parts of the brain (Bregma 3.2 to -2.1mm. After high-fat diet, Slc38a9 was specifically upregulated in hypothalamus, while overall downregulation was noticed throughout the brain (Bregma 3.2 to -8.6mm.

High levels of the type III inorganic phosphate transporter PiT1 (SLC20A1) can confer faster cell adhesion

OpenAIRE

Kongsfelt, Iben Boutrup; Byskov, Kristina; Pedersen, Lasse Ebdrup; Pedersen, Lene

2014-01-01

The inorganic phosphate transporter PiT1 (SLC20A1) is ubiquitously expressed in mammalian cells. We recently showed that overexpression of human PiT1 was sufficient to increase proliferation of two strict density-inhibited cell lines, murine fibroblastic NIH3T3 and pre-osteoblastic MC3T3-E1 cells, and allowed the cultures to grow to higher cell densities. In addition, upon transformation NIH3T3 cells showed increased ability to form colonies in soft agar. The cellular regulation of PiT1 expre...

Genome-wide association analysis confirms and extends the association of SLC2A9 with serum uric acid levels to Mexican Americans

Directory of Open Access Journals (Sweden)

Venkata Saroja eVoruganti

2013-12-01

Full Text Available Increased serum uric acid (SUA is a risk factor for gout and renal and cardiovascular disease. The purpose of this study was to identify genetic factors that affect the variation in SUA in 632 Mexican Americans participants of the San Antonio Family Heart Study (SAFHS. A genome-wide association analysis was performed using the Illumina Human Hap 550K single nucleotide polymorphism (SNP microarray. We used a linear regression-based association test under an additive model of allelic effect, while accounting for non-independence among family members via a kinship variance component. All analyses were performed in the software package SOLAR. SNPs rs6832439, rs13131257 and rs737267 in solute carrier protein 2 family, member 9 (SLC2A9 were associated with SUA at genome-wide significance (p <1.3×10-7. The minor alleles of these SNPs had frequencies of 36.2%, 36.2%, and 38.2 %, respectively, and were associated with decreasing SUA levels. All of these SNPs were located in introns 3-7 of SLC2A9, the location of the previously reported associations in European populations. When analyzed for association with cardiovascular-renal disease risk factors, conditional on SLC2A9 SNPs strongly associated with SUA, significant associations were found for SLC2A9 SNPs with BMI, body weight and waist circumference (p < 1.4 x 10-3 and suggestive associations with albumin-creatinine ratio and total antioxidant status. The SLC2A9 gene encodes an urate transporter that has considerable influence on variation in SUA. In addition to the primary association locus, suggestive evidence (p<1.9×10-6 for joint linkage/association was found at a previously-reported urate quantitative trait locus (Logarithm of odds score = 3.6 on 3p26.3. In summary, our GWAS extends and confirms the association of SLC2A9 with SUA for the first time in a Mexican American cohort and also shows for the first time its association with cardiovascular-renal disease risk factors.

Three-dimensional structure of β-cell-specific zinc transporter, ZnT-8, predicted from the type 2 diabetes-associated gene variant SLC30A8 R325W

Directory of Open Access Journals (Sweden)

Weijers Rob NM

2010-06-01

Full Text Available Abstract Background We examined the effects of the R325W mutation on the three-dimensional (3D structure of the β-cell-specific Zn2+ (zinc transporter ZnT-8. Methods A model of the C-terminal domain of the human ZnT-8 protein was generated by homology modeling based on the known crystal structure of the Escherichia coli (E. coli zinc transporter YiiP at 3.8 Å resolution. Results The homodimer ZnT-8 protein structure exists as a Y-shaped architecture with Arg325 located at the ultimate bottom of this motif at approximately 13.5 Å from the transmembrane domain juncture. The C-terminal domain sequences of the human ZnT-8 protein and the E. coli zinc transporter YiiP share 12.3% identical and 39.5% homologous residues resulting in an overall homology of 51.8%. Validation statistics of the homology model showed a reasonable quality of the model. The C-terminal domain exhibited an αββαβ fold with Arg325 as the penultimate N-terminal residue of the α2-helix. The side chains of both Arg325 and Trp325 point away from the interface with the other monomer, whereas the ε-NH3+ group of Arg325 is predicted to form an ionic interaction with the β-COO- group of Asp326 as well as Asp295. An amino acid alignment of the β2-α2 C-terminal loop domain revealed a variety of neutral amino acids at position 325 of different ZnT-8 proteins. Conclusions Our validated homology models predict that both Arg325 and Trp325, amino acids with a helix-forming behavior, and penultimate N-terminal residues in the α2-helix of the C-terminal domain, are shielded by the planar surface of the three cytoplasmic β-strands and hence unable to affect the sensing capacity of the C-terminal domain. Moreover, the amino acid residue at position 325 is too far removed from the docking and transporter parts of ZnT-8 to affect their local protein conformations. These data indicate that the inherited R325W abnormality in SLC30A8 may be tolerated and results in adequate zinc transfer

Major involvement of Na(+) -dependent multivitamin transporter (SLC5A6/SMVT) in uptake of biotin and pantothenic acid by human brain capillary endothelial cells.

Science.gov (United States)

Uchida, Yasuo; Ito, Katsuaki; Ohtsuki, Sumio; Kubo, Yoshiyuki; Suzuki, Takashi; Terasaki, Tetsuya

2015-07-01

The purpose of this study was to clarify the expression of Na(+) -dependent multivitamin transporter (SLC5A6/SMVT) and its contribution to the supply of biotin and pantothenic acid to the human brain via the blood-brain barrier. DNA microarray and immunohistochemical analyses confirmed that SLC5A6 is expressed in microvessels of human brain. The absolute expression levels of SLC5A6 protein in isolated human and monkey brain microvessels were 1.19 and 0.597 fmol/μg protein, respectively, as determined by a quantitative targeted absolute proteomics technique. Using an antibody-free method established by Kubo et al. (2015), we found that SLC5A6 was preferentially localized at the luminal membrane of brain capillary endothelium. Knock-down analysis using SLC5A6 siRNA showed that SLC5A6 accounts for 88.7% and 98.6% of total [(3) H]biotin and [(3) H]pantothenic acid uptakes, respectively, by human cerebral microvascular endothelial cell line hCMEC/D3. SLC5A6-mediated transport in hCMEC/D3 was markedly inhibited not only by biotin and pantothenic acid, but also by prostaglandin E2, lipoic acid, docosahexaenoic acid, indomethacin, ketoprofen, diclofenac, ibuprofen, phenylbutazone, and flurbiprofen. This study is the first to confirm expression of SLC5A6 in human brain microvessels and to provide evidence that SLC5A6 is a major contributor to luminal uptake of biotin and pantothenic acid at the human blood-brain barrier. In humans, it was unclear (not concluded) about what transport system at the blood-brain barrier (BBB) is responsible for the brain uptakes of two vitamins, biotin and pantothenic acid, which are necessary for brain proper function. This study clarified for the first time that the solute carrier 5A6/Na(+) -dependent multivitamin transporter SLC5A6/SMVT is responsible for the supplies of biotin and pantothenic acid into brain across the BBB in humans. DHA, docosahexaenoic acid; NSAID, non-steroidal anti-inflammatory drug; PGE2, prostaglandin E2. © 2015

Estimated carrier frequency of creatine transporter deficiency in females in the general population using functional characterization of novel missense variants in the SLC6A8 gene.

Science.gov (United States)

DesRoches, Caro-Lyne; Patel, Jaina; Wang, Peixiang; Minassian, Berge; Salomons, Gajja S; Marshall, Christian R; Mercimek-Mahmutoglu, Saadet

2015-07-10

Creatine transporter deficiency (CRTR-D) is an X-linked inherited disorder of creatine transport. All males and about 50% of females have intellectual disability or cognitive dysfunction. Creatine deficiency on brain proton magnetic resonance spectroscopy and elevated urinary creatine to creatinine ratio are important biomarkers. Mutations in the SLC6A8 gene occur de novo in 30% of males. Despite reports of high prevalence of CRTR-D in males with intellectual disability, there are no true prevalence studies in the general population. To determine carrier frequency of CRTR-D in the general population we studied the variants in the SLC6A8 gene reported in the Exome Variant Server database and performed functional characterization of missense variants. We also analyzed synonymous and intronic variants for their predicted pathogenicity using in silico analysis tools. Nine missense variants were functionally analyzed using transient transfection by site-directed mutagenesis with In-Fusion HD Cloning in HeLa cells. Creatine uptake was measured by liquid chromatography tandem mass spectrometry for creatine measurement. The c.1654G>T (p.Val552Leu) variant showed low residual creatine uptake activity of 35% of wild type transfected HeLa cells and was classified as pathogenic. Three variants (c.808G>A; p.Val270Met, c.942C>G; p.Phe314Leu and c.952G>A; p.Ala318Thr) were predicted to be pathogenic based on in silico analysis, but proved to be non-pathogenic by our functional analysis. The estimated carrier frequency of CRTR-D was 0.024% in females in the general population. We recommend functional studies for all novel missense variants by transient transfection followed by creatine uptake measurement by liquid chromatography tandem mass spectrometry as fast and cost effective method for the functional analysis of missense variants in the SLC6A8 gene. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

Downregulation of SLC7A7 Triggers an Inflammatory Phenotype in Human Macrophages and Airway Epithelial Cells

Directory of Open Access Journals (Sweden)

Bianca Maria Rotoli

2018-03-01

Full Text Available Lysinuric protein intolerance (LPI is a recessively inherited aminoaciduria caused by mutations of SLC7A7, the gene encoding y+LAT1 light chain of system y+L for cationic amino acid transport. The pathogenesis of LPI is still unknown. In this study, we have utilized a gene silencing approach in macrophages and airway epithelial cells to investigate whether complications affecting lung and immune system are directly ascribable to the lack of SLC7A7 or, rather, mediated by an abnormal accumulation of arginine in mutated cells. When SLC7A7/y+LAT1 was silenced in human THP-1 macrophages and A549 airway epithelial cells by means of short interference RNA (siRNA, a significant induction of the expression and release of the inflammatory mediators IL1β and TNFα was observed, no matter the intracellular arginine availability. This effect was mainly regulated at transcriptional level through the activation of NFκB signaling pathway. Moreover, since respiratory epithelial cells are the important sources of chemokines in response to pro-inflammatory stimuli, the effect of IL1β has been addressed on SLC7A7 silenced A549 cells. Results obtained indicated that the downregulation of SLC7A7/y+LAT1 markedly strengthened the stimulatory effect of the cytokine on CCL5/RANTES expression and release without affecting the levels of CXCL8/IL8. Consistently, also the conditioned medium of silenced THP-1 macrophages activated airway epithelial cells in terms of CCL5/RANTES expression due to the presence of elevated amount of proinflammatory cytokines. In conclusion, our results point to a novel thus far unknown function of SLC7A7/y+LAT1, that, under physiological conditions, besides transporting arginine, may act as a brake to restrain inflammation.

mTORC1 Activator SLC38A9 Is Required to Efflux Essential Amino Acids from Lysosomes and Use Protein as a Nutrient.

Science.gov (United States)

Wyant, Gregory A; Abu-Remaileh, Monther; Wolfson, Rachel L; Chen, Walter W; Freinkman, Elizaveta; Danai, Laura V; Vander Heiden, Matthew G; Sabatini, David M

2017-10-19

The mTORC1 kinase is a master growth regulator that senses many environmental cues, including amino acids. Activation of mTORC1 by arginine requires SLC38A9, a poorly understood lysosomal membrane protein with homology to amino acid transporters. Here, we validate that SLC38A9 is an arginine sensor for the mTORC1 pathway, and we uncover an unexpectedly central role for SLC38A9 in amino acid homeostasis. SLC38A9 mediates the transport, in an arginine-regulated fashion, of many essential amino acids out of lysosomes, including leucine, which mTORC1 senses through the cytosolic Sestrin proteins. SLC38A9 is necessary for leucine generated via lysosomal proteolysis to exit lysosomes and activate mTORC1. Pancreatic cancer cells, which use macropinocytosed protein as a nutrient source, require SLC38A9 to form tumors. Thus, through SLC38A9, arginine serves as a lysosomal messenger that couples mTORC1 activation to the release from lysosomes of the essential amino acids needed to drive cell growth. Copyright © 2017 Elsevier Inc. All rights reserved.

Global transcriptome profiling identifies KLF15 and SLC25A10 as modifiers of adipocytes insulin sensitivity in obese women.

Directory of Open Access Journals (Sweden)

Agné Kulyté

Full Text Available Although the mechanisms linking obesity to insulin resistance (IR and type 2 diabetes (T2D are not entirely understood, it is likely that alterations of adipose tissue function are involved. The aim of this study was to identify new genes controlling insulin sensitivity in adipocytes from obese women with either insulin resistant (OIR or sensitive (OIS adipocytes. Insulin sensitivity was first determined by measuring lipogenesis in isolated adipocytes from abdominal subcutaneous white adipose tissue (WAT in a large observational study. Lipogenesis was measured under conditions where glucose transport was the rate limiting step and reflects in vivo insulin sensitivity. We then performed microarray-based transcriptome profiling on subcutaneous WAT specimen from a subgroup of 9 lean, 21 OIS and 18 obese OIR women. We could identify 432 genes that were differentially expressed between the OIR and OIS group (FDR ≤5%. These genes are enriched in pathways related to glucose and amino acid metabolism, cellular respiration, and insulin signaling, and include genes such as SLC2A4, AKT2, as well as genes coding for enzymes in the mitochondria respiratory chain. Two IR-associated genes, KLF15 encoding a transcription factor and SLC25A10 encoding a dicarboxylate carrier, were selected for functional evaluation in adipocytes differentiated in vitro. Knockdown of KLF15 and SLC25A10 using siRNA inhibited insulin-stimulated lipogenesis in adipocytes. Transcriptome profiling of siRNA-treated cells suggested that KLF15 might control insulin sensitivity by influencing expression of PPARG, PXMP2, AQP7, LPL and genes in the mitochondrial respiratory chain. Knockdown of SLC25A10 had only modest impact on the transcriptome, suggesting that it might directly influence insulin sensitivity in adipocytes independently of transcription due to its important role in fatty acid synthesis. In summary, this study identifies novel genes associated with insulin sensitivity in

Dysplastic spondylolysis is caused by mutations in the diastrophic dysplasia sulfate transporter gene.

Science.gov (United States)

Cai, Tao; Yang, Liu; Cai, Wanshi; Guo, Sen; Yu, Ping; Li, Jinchen; Hu, Xueyu; Yan, Ming; Shao, Qianzhi; Jin, Yan; Sun, Zhong Sheng; Luo, Zhuo-Jing

2015-06-30

Spondylolysis is a fracture in part of the vertebra with a reported prevalence of about 3-6% in the general population. Genetic etiology of this disorder remains unknown. The present study was aimed at identifying genomic mutations in patients with dysplastic spondylolysis as well as the potential pathogenesis of the abnormalities. Whole-exome sequencing and functional analysis were performed for patients with spondylolysis. We identified a novel heterozygous mutation (c.2286A > T; p.D673V) in the sulfate transporter gene SLC26A2 in five affected subjects of a Chinese family. Two additional mutations (e.g., c.1922A > G; p.H641R and g.18654T > C in the intron 1) in the gene were identified by screening a cohort of 30 unrelated patients with the disease. In situ hybridization analysis showed that SLC26A2 is abundantly expressed in the lumbosacral spine of the mouse embryo at day 14.5. Sulfate uptake activities in CHO cells transfected with mutant SLC26A2 were dramatically reduced compared with the wild type, confirming the pathogenicity of the two missense mutations. Further analysis of the gene-disease network revealed a convergent pathogenic network for the development of lumbosacral spine. To our knowledge, our findings provide the first identification of autosomal dominant SLC26A2 mutations in patients with dysplastic spondylolysis, suggesting a new clinical entity in the pathogenesis of chondrodysplasia involving lumbosacral spine. The analysis of the gene-disease network may shed new light on the study of patients with dysplastic spondylolysis and spondylolisthesis as well as high-risk individuals who are asymptomatic.

The histidine transporter SLC15A4 coordinates mTOR-dependent inflammatory responses and pathogenic antibody production.

Science.gov (United States)

Kobayashi, Toshihiko; Shimabukuro-Demoto, Shiho; Yoshida-Sugitani, Reiko; Furuyama-Tanaka, Kaori; Karyu, Hitomi; Sugiura, Yuki; Shimizu, Yukiko; Hosaka, Toshiaki; Goto, Motohito; Kato, Norihiro; Okamura, Tadashi; Suematsu, Makoto; Yokoyama, Shigeyuki; Toyama-Sorimachi, Noriko

2014-09-18

SLC15A4 is a lysosome-resident, proton-coupled amino-acid transporter that moves histidine and oligopeptides from inside the lysosome to the cytosol of eukaryotic cells. SLC15A4 is required for Toll-like receptor 7 (TLR7)- and TLR9-mediated type I interferon (IFN-I) productions in plasmacytoid dendritic cells (pDCs) and is involved in the pathogenesis of certain diseases including lupus-like autoimmunity. How SLC15A4 contributes to diseases is largely unknown. Here we have shown that B cell SLC15A4 was crucial for TLR7-triggered IFN-I and autoantibody productions in a mouse lupus model. SLC15A4 loss disturbed the endolysosomal pH regulation and probably the v-ATPase integrity, and these changes were associated with disruption of the mTOR pathway, leading to failure of the IFN regulatory factor 7 (IRF7)-IFN-I regulatory circuit. Importantly, SLC15A4's transporter activity was necessary for the TLR-triggered cytokine production. Our findings revealed that SLC15A4-mediated optimization of the endolysosomal state is integral to a TLR7-triggered, mTOR-dependent IRF7-IFN-I circuit that leads to autoantibody production. Copyright © 2014 Elsevier Inc. All rights reserved.

Clinical presentation and outcome of riboflavin transporter deficiency: mini review after five years of experience

NARCIS (Netherlands)

Jaeger, Bregje; Bosch, Annet M.

2016-01-01

Riboflavin (vitamin B2) is absorbed in the small intestine by the human riboflavin transporters RFVT1 and RFVT3. A third riboflavin transporter (RFVT2) is expressed in the brain. In 2010 it was demonstrated that mutations in the riboflavin transporter genes SLC52A2 (coding for RFVT2) and SLC52A3

Distribution and expression of SLC45A2 in the skin of sheep with different coat colors.

Science.gov (United States)

Wang, Haidong; Xue, Linli; Li, Yanan; Zhao, Bingling; Chen, Tianzhi; Liu, Ying; Chang, Lucheng; Wang, Juan

2016-01-01

To investigate whether the membrane-associated transporter protein SLC45A2 is differentially expressed in the skin of sheep with different coat colors and to determine its correlation with coat color establishment in sheep. The expression of SLC45A2 in sheep skin samples with different coat colors was qualitatively and quantitatively analyzed by PCR amplification, RT-PCR, immunohistochemical staining and Western blotting. A 193-bp SLC45A2 CDS sequence was successfully amplified from sheep skin samples with diverse coat colors. RT-PCR analysis revealed that SLC45A2 mRNA was expressed in all sheep skin samples tested, with relative expression levels of 512.74 ± 121.51 in black skin, 143.38 ± 119.31 and 1.36 ± 0.09 in black dots and white dots of piebald skin, respectively, and 1.02 ± 0.23 in white skin (p coat colors. These patterns were quantified by optical density (OD) analysis, which yielded relative expression levels of 0.23 ± 0.11 in black skin, 0.19 ± 0.09 and 0.10 ± 0.03 in black dots and white dots of piebald skin, respectively, and 0.08 ± 0.01 in white skin (p coat colors, though at significantly different levels. SLC45A2 may participate in the establishment of coat color by regulating the synthesis and trafficking of melanin.

Examining the role of components of Slc11a1 (Nramp1 in the susceptibility of New Zealand sea lions (Phocarctos hookeri to disease.

Directory of Open Access Journals (Sweden)

Amy J Osborne

Full Text Available The New Zealand sea lion (NZSL, Phocarctos hookeri is a Threatened marine mammal with a restricted distribution and a small, declining, population size. The species is susceptible to bacterial pathogens, having suffered three mass mortality events since 1998. Understanding the genetic factors linked to this susceptibility is important in mitigating population decline. The gene solute carrier family 11 member a1 (Slc11a1 plays an important role in mammalian resistance or susceptibility to a wide range of bacterial pathogens. At present, Slc11a1 has not been characterised in many taxa, and despite its known roles in mediating the effects of infectious disease agents, has not been examined as a candidate gene in susceptibility or resistance in any wild population of conservation concern. Here we examine components of Slc11a1 in NZSLs and identify: i a polymorphic nucleotide in the promoter region; ii putative shared transcription factor binding motifs between canids and NZSLs; and iii a conserved polymorphic microsatellite in the first intron of Slc11a1, which together suggest conservation of Slc11a1 gene structure in otariids. At the promoter polymorphism, we demonstrate a shift away from normal allele frequency distributions and an increased likelihood of death from infectious causes with one allelic variant. While this increased likelihood is not statistically significant, lack of significance is potentially due to the complexity of genetic susceptibility to disease in wild populations. Our preliminary data highlight the potential significance of this gene in disease resistance in wild populations; further exploration of Slc11a1 will aid the understanding of susceptibility to infection in mammalian species of conservation significance.

SLC25A13 gene analysis in citrin deficiency: sixteen novel mutations in East Asian patients, and the mutation distribution in a large pediatric cohort in China.

Directory of Open Access Journals (Sweden)

Yuan-Zong Song

Full Text Available BACKGROUND: The human SLC25A13 gene encodes citrin, the liver-type mitochondrial aspartate/glutamate carrier isoform 2 (AGC2, and SLC25A13 mutations cause citrin deficiency (CD, a disease entity that encompasses different age-dependant clinical phenotypes such as Adult-onset Citrullinemia Type II (CTLN2 and Neonatal Intrahepatic Cholestasis caused by Citrin Deficiency (NICCD. The analyses of SLC25A13 gene and its protein/mRNA products remain reliable tools for the definitive diagnoses of CD patients, and so far, the SLC25A13 mutation spectrum in Chinese CD patients has not been well-characterized yet. METHODS AND RESULTS: By means of direct DNA sequencing, cDNA cloning and SNP analyses, 16 novel pathogenic mutations, including 9 missense, 4 nonsense, 1 splice-site, 1 deletion and 1 large transposal insertion IVS4ins6kb (GenBank accession number KF425758, were identified in CTLN2 or NICCD patients from China, Japan and Malaysia, respectively, making the SLC25A13 variations worldwide reach the total number of 81. A large NICCD cohort of 116 Chinese cases was also established, and the 4 high-frequency mutations contributed a much larger proportion of the mutated alleles in the patients from south China than in those from the north (χ(2 = 14.93, P<0.01, with the latitude of 30°N as the geographic dividing line in mainland China. CONCLUSIONS: This paper further enriched the SLC25A13 variation spectrum worldwide, and formed a substantial contribution to the in-depth understanding of the genotypic feature of Chinese CD patients.

S113R mutation in SLC33A1 leads to neurodegeneration and augmented BMP signaling in a mouse model

Directory of Open Access Journals (Sweden)

Pingting Liu

2017-01-01

Full Text Available The S113R mutation (c.339T>G (MIM #603690.0001 in SLC33A1 (MIM #603690, an ER membrane acetyl-CoA transporter, has been previously identified in individuals with hereditary spastic paraplegia type 42 (SPG42; MIM #612539. SLC33A1 has also been shown to inhibit the bone morphogenetic protein (BMP signaling pathway in zebrafish. To better understand the function of SLC33A1, we generated and characterized Slc33a1S113R knock-in mice. Homozygous Slc33a1S113R mutant mice were embryonic lethal, whereas heterozygous Slc33a1 mutant mice (Slc33a1wt/mut exhibited behavioral abnormalities and central neurodegeneration, which is consistent with hereditary spastic paraplegia (HSP phenotypes. Importantly, we found an upregulation of BMP signaling in the nervous system and mouse embryonic fibroblasts of Slc33a1wt/mut mice. Using a sciatic nerve crush injury model in vivo and dorsal root ganglion (DRG culture in vitro we showed that injury-induced axonal regeneration in Slc33a1wt/mut mice was accelerated and mediated by upregulated BMP signaling. Exogenous addition of BMP signaling antagonist, noggin, could efficiently alleviate the accelerated injury-induced axonal regrowth. These results indicate that SLC33A1 can negatively regulate BMP signaling in mice, further supporting the notion that upregulation of BMP signaling is a common mechanism of a subset of hereditary spastic paraplegias.

Response to crizotinib in a lung adenocarcinoma patient harboring a novel SLC34A2-ROS1 fusion variant

Science.gov (United States)

Zhao, Zheng; Song, Zhangjun; Wang, Xuwei; Sun, Haifeng; Yang, Xiaomin; Yuan, Yong; Yu, Pan

2017-01-01

ROS1 fusion is a common genetic alteration in non-small-cell lung cancer. Crizotinib, an anaplastic lymphoma kinase inhibitor, shows efficacy in the treatment of lung cancer cases with ROS1 translocation. We report the response to crizotinib of a lung adenocarcinoma patient harboring a novel SLC34A2-ROS1 fusion variant, which was different from the two common SLC34A2-ROS1 fusion types reported in the literature. After crizotinib administration, overall recovery was good in this patient; the primary lesion was successfully treated, the lymph node metastases had disappeared, and the metabolism was normal. PMID:28860822

Looking on the bright side of serotonin transporter gene variation.

NARCIS (Netherlands)

Homberg, J.R.; Lesch, K.P.

2011-01-01

Converging evidence indicates an association of the short (s), low-expressing variant of the repeat length polymorphism, serotonin transporter-linked polymorphic region (5-HTTLPR), in the human serotonin transporter gene (5-HTT, SERT, SLC6A4) with anxiety-related traits and increased risk for

ASCT2 (SLC1A5-Deficient Mice Have Normal B-Cell Development, Proliferation, and Antibody Production

Directory of Open Access Journals (Sweden)

Etienne Masle-Farquhar

2017-05-01

Full Text Available SLC1A5 (solute carrier family 1, member 5 is a small neutral amino acid exchanger that is upregulated in rapidly proliferating lymphocytes but also in many primary human cancers. Furthermore, cancer cell lines have been shown to require SLC1A5 for their survival in vitro. One of SLC1A5’s primary substrates is the immunomodulatory amino acid glutamine, which plays an important role in multiple key processes, such as energy supply, macromolecular synthesis, nucleotide biosynthesis, redox homeostasis, and resistance against oxidative stress. These processes are also essential to immune cells, including neutrophils, macrophages, B and T lymphocytes. We show here that mice with a stop codon in Slc1a5 have reduced glutamine uptake in activated lymphocytes and primary fibroblasts. B and T cell populations and maturation in resting mice were not affected by absence of SLC1A5. Antibody production in resting and immunized mice and the germinal center response to immunization were also found to be normal. SLC1A5 has been recently described as a novel target for the treatment of a variety of cancers, and our results indicate that inhibition of SLC1A5 in cancer therapy may be tolerated well by the immune system of cancer patients.

Gene expression of membrane transporters: Importance for prognosis and progression of ovarian carcinoma

Czech Academy of Sciences Publication Activity Database

Elsnerová, K.; Mohelniková; Duchonová, B.; Čeřovská, E.; Ehrlichová, M.; Gut, I.; Rob, L.; Skapa, P.; Hruda, M.; Bartáková, A.; Bouda, J.; Vodička, Pavel; Souček, P.; Václavíková, R.

2016-01-01

Roč. 35, č. 4 (2016), s. 2159-2170 ISSN 1021-335X R&D Projects: GA MZd(CZ) NT14056; GA MŠk(CZ) LD14050 Institutional support: RVO:68378041 Keywords : epithelial ovarian cancer * ABC transporters * SLC transporters * gene expression * prognosis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.662, year: 2016

[Role of Serotonin Transporter Gene in Eating Disorders].

Science.gov (United States)

Hernández-Muñoz, Sandra; Camarena-Medellin, Beatriz

2014-01-01

The serotoninergic system has been implicated in mood and appetite regulation, and the serotonin transporter gene (SLC6A4) is a commonly studied candidate gene for eating disorders. However, most studies have focused on a single polymorphism (5-HTTLPR) in SLC6A4. We present the studies published on the association between eating disorders (ED) and 5-HTTLPR polymorphism in anorexia nervosa (AN), bulimia nervosa (BN), and eating disorders not otherwise specified (EDNOS). Search of databases: MEDLINE, ISI, and PubMed for SLC6A4 and ED. From a review of 37 original articles, it was suggested that carriers of S allele is a risk factor for eating disorders, especially for AN. However, BN did not show any association. Also, BMI, impulsivity, anxiety, depression, and age of onset have been associated with S allele in ED patients. Copyright © 2013 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

Association between the SLC6A3 A1343G polymorphism and schizophrenia Associação entre o polimorfismo A1343G do SLC6A3 e esquizofrenia

Directory of Open Access Journals (Sweden)

Quirino Cordeiro

2010-10-01

Full Text Available Epidemiological studies have demonstrated that the genetic component is an important risk factor for the development of schizophrenia. The genes that codify the different compounds of the dopaminergic system have created interest for molecular investigations in patients with schizophrenia because the antipsychotic drugs, especially those of first generation, act on this cerebral system. Thus the aim of the present study was to investigate the possible association between a new single nucleotide polymorphism (rs6347 located in exon 9 of the protein transporter (SLC6A3 and schizophrenia. The distribution of the alleles and genotypes of the studied polymorphism was investigated in a sample of 235 patients and 834 controls matched by gender and age. There were statistical differences in the allelic (χ2=5.97, 1d.f. , p=0.01, OR=1.33-1.05Estudos epidemiológicos têm demonstrado que o componente genético é um importante fator de risco para a esquizofrenia. Os genes que codificam os diferentes componentes do sistema dopaminérgico passaram a despertar interesse para estudos moleculares em pacientes com esquizofrenia, pois os antipsicóticos, em especial os de primeira geração, exercem sua ação nesse sistema. Assim, o objetivo do presente estudo foi investigar a associação entre um novo polimorfismo de nucleotídeo único (rs6347 localizado no exon 9 do gene do transportador de dopamina (SLC6A3 e esquizofrenia. Um total de 235 pacientes e 834 controles pareados para sexo e idade foi selecionado para a investigação da distribuição dos alelos e genótipos do polimorfismo investigado entre os grupos de pacientes e controles. Houve diferenças estatisticamente significantes nas distribuições alélicas (χ2=5,97, 1d.f. , p=0,01, OR=1,33-1,051,69 e genotípicas (χ2=6,56, 2d.f. , p=0,03 entre pacientes e controles. Assim, o polimorfismo SLC6A3 A1343G mostrou associação com esquizofrenia na amostra estudada.

Transport mechanism and regulatory properties of the human amino acid transporter ASCT2 (SLC1A5).

Science.gov (United States)

Scalise, Mariafrancesca; Pochini, Lorena; Panni, Simona; Pingitore, Piero; Hedfalk, Kristina; Indiveri, Cesare

2014-11-01

The kinetic mechanism of the transport catalyzed by the human glutamine/neutral amino acid transporter hASCT2 over-expressed in P. pastoris was determined in proteoliposomes by pseudo-bi-substrate kinetic analysis of the Na(+)-glutamineex/glutaminein transport reaction. A random simultaneous mechanism resulted from the experimental analysis. Purified functional hASCT2 was chemically cross-linked to a stable dimeric form. The oligomeric structure correlated well with the kinetic mechanism of transport. Half-saturation constants (Km) of the transporter for the other substrates Ala, Ser, Asn and Thr were measured both on the external and internal side. External Km were much lower than the internal ones confirming the asymmetry of the transporter. The electric nature of the transport reaction was determined imposing a negative inside membrane potential generated by K(+) gradients in the presence of valinomycin. The transport reaction resulted to be electrogenic and the electrogenicity originated from external Na(+). Internal Na(+) exerted a stimulatory effect on the transport activity which could be explained by a regulatory, not a counter-transport, effect. Native and deglycosylated hASCT2 extracted from HeLa showed the same transport features demonstrating that the glycosyl moiety has no role in transport function. Both in vitro and in vivo interactions of hASCT2 with the scaffold protein PDZK1 were revealed.

The copper transporter (SLC31A1/CTR1) is expressed in bovine spermatozoa and oocytes: Copper in IVF medium improves sperm quality.

Science.gov (United States)

Anchordoquy, J P; Anchordoquy, J M; Pascua, A M; Nikoloff, N; Peral-García, P; Furnus, C C

2017-07-15

Adequate dietary intake of copper (Cu) is required for normal reproductive performance in cattle. The objective of this study was to investigate the pregnancy rates from cattle with deficient, marginal and adequate Cu plasma concentration at the beginning of artificial insemination protocol. Moreover, we determined Cu concentrations present in bovine oviductal fluid (OF), and the effects of Cu on fertilizing ability of bovine spermatozoa. Also, the presence of Cu transporter, SLC31A1 (also known as CTR1), in spermatozoa and in vitro matured oocyte were investigated. We found no differences in pregnancy rates among animals with adequate, marginal, and deficient Cu concentrations measured in plasma at the beginning of fixed-time artificial insemination (FTAI) protocol. Copper concentrations in OF were 38.3 ± 2.17 μg/dL (mean ± SEM) regardless of cupremia levels. The addition of 40 μg/dL Cu to IVF medium enhanced total and progressive motility, sperm viability, functional sperm membrane integrity (HOST), sperm-zona binding, and pronuclear formation. On the other hand, the presence of Cu in IVF medium did not modify acrosome integrity and cleavage rates after IVF, but impaired blastocyst rates. Cu transporter SLC31A1 was detected in bovine spermatozoa in the apical segment of acrosome, and in the oocyte matured in vitro. In conclusion, the results obtained in the present study determined that cupremia levels at the beginning of FTAI protocol did not influence the pregnancy rates at 60 d after insemination. The presence of CTR1 in bovine mature oocyte and spermatozoa, as well as the beneficial effect of Cu on sperm quality would suggest an important role of this mineral during the fertilization process. Copyright © 2017 Elsevier Inc. All rights reserved.

Determination of Unbound Partition Coefficient and in Vitro-in Vivo Extrapolation for SLC13A Transporter-Mediated Uptake.

Science.gov (United States)

Riccardi, Keith; Li, Zhenhong; Brown, Janice A; Gorgoglione, Matthew F; Niosi, Mark; Gosset, James; Huard, Kim; Erion, Derek M; Di, Li

2016-10-01

Unbound partition coefficient (Kpuu) is important to an understanding of the asymmetric free drug distribution of a compound between cells and medium in vitro, as well as between tissue and plasma in vivo, especially for transporter-mediated processes. Kpuu was determined for a set of compounds from the SLC13A family that are inhibitors and substrates of transporters in hepatocytes and transporter-transfected cell lines. Enantioselectivity was observed, with (R)-enantiomers achieving much higher Kpuu (>4) than the (S)-enantiomers (<1) in human hepatocytes and SLC13A5-transfected human embryonic 293 cells. The intracellular free drug concentration correlated directly with in vitro pharmacological activity rather than the nominal concentration in the assay because of the high Kpuu mediated by SLC13A5 transporter uptake. Delivery of the diacid PF-06649298 directly or via hydrolysis of the ethyl ester prodrug PF-06757303 resulted in quite different Kpuu values in human hepatocytes (Kpuu of 3 for diacid versus 59 for prodrug), which was successfully modeled on the basis of passive diffusion, active uptake, and conversion rate from ester to diacid using a compartmental model. Kpuu values changed with drug concentrations; lower values were observed at higher concentrations possibly owing to a saturation of transporters. Michaelis-Menten constant (Km) of SLC13A5 was estimated to be 24 μM for PF-06649298 in human hepatocytes. In vitro Kpuu obtained from rat suspension hepatocytes supplemented with 4% fatty acid free bovine serum albumin showed good correlation with in vivo Kpuu of liver-to-plasma, illustrating the potential of this approach to predict in vivo Kpuu from in vitro systems. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.