Genetic variations in urate transporters play a significant role in determining human urate levels and have been implicated in developing hyperuricemia or gout. Polymorphism in the key urate transporters, such as ABCG2, URAT1, or GLUT9 was well-documented in the literature. Therefore in this study, our objective was to determine the frequency and effect of rare nonsynonymous allelic variants of SLC22A11, SLC22A13, and SLC17A1 on urate transport. In a cohort of 150 Czech patients with primary hyperuricemia and gout, we examined all coding regions and exon-intron boundaries of SLC22A11, SLC22A13, and SLC17A1 using PCR amplification and Sanger sequencing. For comparison, we used a control group consisting of 115 normouricemic subjects. To examine the effects of the rare allelic nonsynonymous variants on the expression, intracellular processing, and urate transporter protein function, we performed a functional characterization using the HEK293A cell line, immunoblotting, fluorescent microscopy, and site directed mutagenesis for preparing variants in vitro. Variants p.V202M (rs201209258), p.R343L (rs75933978), and p.P519L (rs144573306) were identified in the SLC22A11 gene (OAT4 transporter); variants p.R16H (rs72542450), and p.R102H (rs113229654) in the SLC22A13 gene (OAT10 transporter); and the p.W75C variant in the SLC17A1 gene (NPT1 transporter). All variants minimally affected protein levels and cytoplasmic/plasma membrane localization. The functional in vitro assay revealed that contrary to the native proteins, variants p.P519L in OAT4 (p ≤ 0.05), p.R16H in OAT10 (p ≤ 0.05), and p.W75C in the NPT1 transporter (p ≤ 0.01) significantly limited urate transport activity. Our findings contribute to a better understanding of (1) the risk of urate transporter-related hyperuricemia/gout and (2) uric acid handling in the kidneys.

• MeSH
• dna (nemoc) * genetika   MeSH
• hyperurikemie * genetika   MeSH
• kotransportní proteiny pro sodík a fosfát - typ I * genetika   MeSH
• kyselina močová metabolismus   MeSH
• lidé MeSH
• přenašeče organických aniontů nezávislé na sodíku * genetika   MeSH
• přenašeče organických aniontů * genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

One of the principal mechanisms of chemotherapy resistance in highly frequent solid tumors, such as colorectal cancer (CRC), is the decreased activity of drug transport into tumor cells due to low expression of important membrane proteins, such as solute carrier (SLC) transporters. Sequence complementarity is a major determinant for target gene recognition by microRNAs (miRNAs). Single-nucleotide polymorphisms (SNPs) in target sequences transcribed into messenger RNA may therefore alter miRNA binding to these regions by either creating a new site or destroying an existing one. miRSNPs may explain the modulation of expression levels in association with increased/decreased susceptibility to common diseases as well as in chemoresistance and the consequent inter-individual variability in drug response. In the present study, we investigated whether miRSNPs in SLC transporter genes may modulate CRC susceptibility and patient's survival. Using an in silico approach for functional predictions, we analyzed 26 miRSNPs in 9 SLC genes in a cohort of 1368 CRC cases and 698 controls from the Czech Republic. After correcting for multiple tests, we found several miRSNPs significantly associated with patient's survival. SNPs in SLCO3A1, SLC22A2 and SLC22A3 genes were defined as prognostic factors in the classification and regression tree analysis. In contrast, we did not observe any significant association between miRSNPs and CRC risk. To the best of our knowledge, this is the first study investigating miRSNPs potentially affecting miRNA binding to SLC transporter genes and their impact on CRC susceptibility or patient's prognosis.

• MeSH
• 3' nepřekládaná oblast genetika   MeSH
• adjuvantní chemoterapie MeSH
• genetická predispozice k nemoci MeSH
• jednonukleotidový polymorfismus MeSH
• kolorektální nádory krev   genetika   mortalita   terapie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• lokální recidiva nádoru epidemiologie   prevence a kontrola   MeSH
• messenger RNA krev   genetika   MeSH
• mikro RNA krev   metabolismus   MeSH
• následné studie MeSH
• přenašeče organických aniontů genetika   MeSH
• prognóza MeSH
• proteiny přenášející organické kationty genetika   MeSH
• regulace genové exprese u nádorů MeSH
• senioři MeSH
• studie případů a kontrol MeSH
• transportér organických kationtů 2 genetika   MeSH
• vazebná místa genetika   MeSH
• výpočetní biologie MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• pozorovací studie MeSH
• práce podpořená grantem MeSH

The ABCG2 gene is a well-established hyperuricemia/gout risk locus encoding a urate transporter that plays a crucial role in renal and intestinal urate excretion. Hitherto, p.Q141K-a common variant of ABCG2 exhibiting approximately one half the cellular function compared to the wild-type-has been reportedly associated with early-onset gout in some populations. However, compared with adult-onset gout, little clinical information is available regarding the association of other uricemia-associated genetic variations with early-onset gout; the latent involvement of ABCG2 in the development of this disease requires further evidence. We describe a representative case of familial pediatric-onset hyperuricemia and early-onset gout associated with a dysfunctional ABCG2, i.e., a clinical history of three generations of one Czech family with biochemical and molecular genetic findings. Hyperuricemia was defined as serum uric acid (SUA) concentrations 420 μmol/L for men or 360 μmol/L for women and children under 15 years on two measurements, performed at least four weeks apart. The proband was a 12-year-old girl of Roma ethnicity, whose SUA concentrations were 397-405 µmol/L. Sequencing analyses focusing on the coding region of ABCG2 identified two rare mutations-c.393G>T (p.M131I) and c.706C>T (p.R236X). Segregation analysis revealed a plausible link between these mutations and hyperuricemia and the gout phenotype in family relatives. Functional studies revealed that p.M131I and p.R236X were functionally deficient and null, respectively. Our findings illustrate why genetic factors affecting ABCG2 function should be routinely considered in clinical practice as part of a hyperuricemia/gout diagnosis, especially in pediatric-onset patients with a strong family history.

• MeSH
• ABC transportér z rodiny G, člen 2 genetika   metabolismus   MeSH
• dítě MeSH
• dna (nemoc) komplikace   genetika   MeSH
• dospělí MeSH
• fenotyp MeSH
• genetická predispozice k nemoci MeSH
• HEK293 buňky MeSH
• hyperurikemie krev   komplikace   genetika   MeSH
• jednonukleotidový polymorfismus * MeSH
• kyselina močová krev   MeSH
• lidé MeSH
• mutace MeSH
• nádorové proteiny genetika   metabolismus   MeSH
• přenašeče organických aniontů genetika   metabolismus   MeSH
• rodokmen MeSH
• transfekce MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

BACKGROUND AND OBJECTIVE: Membrane solute carrier transporters play an important role in the transport of a wide spectrum of substrates including anticancer drugs and cancer-related physiological substrates. This study aimed to assess the prognostic relevance of gene expression and genetic variability of selected solute carrier transporters in breast cancer. METHODS: Gene expression was determined by quantitative real-time polymerase chain reaction. All SLC46A1 and SLCO1A2 exons and surrounding non-coding sequences in DNA extracted from the blood of patients with breast cancer (exploratory phase) were analyzed by next-generation sequencing technology. Common variants (minor allele frequency ≥ 5%) with in silico-predicted functional relevance were further analyzed in a large cohort of patients with breast cancer (n = 815) and their prognostic and predictive potential was estimated (validation phase). RESULTS: A gene expression and bioinformatics analysis suggested SLC46A1 and SLCO1A2 to play a putative role in the prognosis of patients with breast cancer. In total, 135 genetic variants (20 novel) were identified in both genes in the exploratory phase. Of these variants, 130 were non-coding, three missense, and two synonymous. One common variant in SLCO1A2 and four variants in SLC46A1 were predicted to be pathogenic by in silico programs and subsequently validated. A SLC46A1 haplotype block composed of rs2239911-rs2239910-rs8079943 was significantly associated with ERBB2/HER2 status and disease-free survival of hormonally treated patients. CONCLUSIONS: This study revealed the prognostic value of a SLC46A1 haplotype block for breast cancer that should be further studied.

• MeSH
• analýza přežití MeSH
• folátový přenašeč spřažený s transportem protonů genetika   MeSH
• genetická variace * MeSH
• haplotypy MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• lidé MeSH
• nádorové biomarkery genetika   MeSH
• nádory prsu genetika   MeSH
• přenašeče organických aniontů genetika   MeSH
• prognóza MeSH
• regulace genové exprese u nádorů MeSH
• sekvenční analýza DNA MeSH
• vysoce účinné nukleotidové sekvenování MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Special attention is required when pharmacological treatment is indicated for a pregnant woman. P-glycoprotein (MDR1) is a well-known transporter localized in the maternal blood-facing apical membrane of placental syncytiotrophoblast and is considered to play an important role in protecting the developing fetus. Maraviroc, a MDR1 substrate that is registered for treatment of HIV infection, shows a low toxicity profile, suggesting favorable tolerability also if administered to pregnant women. Nevertheless, there is only poor understanding to date regarding the extent to which it permeates across the placental barrier and what are the transport mechanisms involved. Endeavoring to clarify the passage of maraviroc across placenta, we used in this study the method of closed-circuit perfusion of maraviroc across human placental cotyledon. The data obtained confirmed slight involvement of MDR1, but they also suggest possible interaction with other transport system(s) working in the opposite direction from that of MDR1. Complementary in vitro studies, including cellular experiments on choriocarcinoma BeWo cells as well as transporter-overexpressing MDCKII and A431 cell lines and accumulation in placental fresh villous fragments, revealed maraviroc transport by MRP1, OATP1A2, and OATP1B3 transporters. Based on mRNA expression data in the placental tissue, isolated trophoblasts, and fetal endothelial cells, especially MRP1 and OATP1A2 seem to play a crucial role in cooperatively driving maraviroc into placental tissue. By the example of maraviroc, we show here the important interplay of transporters in placental drug handling and its possibility to overcome the MDR1-mediated efflux.

• MeSH
• akridiny farmakologie   MeSH
• buňky MDCK MeSH
• látky proti HIV krev   metabolismus   farmakologie   MeSH
• lékové interakce MeSH
• lidé MeSH
• maravirok krev   metabolismus   MeSH
• nádorové buněčné linie MeSH
• P-glykoproteiny antagonisté a inhibitory   genetika   metabolismus   MeSH
• perfuze MeSH
• placenta účinky léků   metabolismus   MeSH
• placentární oběh MeSH
• přenašeče organických aniontů antagonisté a inhibitory   genetika   metabolismus   MeSH
• protein OATP1B3 antagonisté a inhibitory   genetika   metabolismus   MeSH
• proteiny spojené s mnohočetnou rezistencí k lékům genetika   metabolismus   MeSH
• psi MeSH
• regulace genové exprese MeSH
• ritonavir farmakologie   MeSH
• těhotenství MeSH
• tetrahydroisochinoliny farmakologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• psi MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Changes in ecological and environmental factors lead to an increased occurrence of cyanobacterial water blooms, while secondary metabolites-producing cyanobacteria pose a threat to both environmental and human health. Apart from oral and dermal exposure, humans may be exposed via inhalation and/or swallowing of contaminated water and aerosols. Although many studies deal with liver toxicity, less information about the effects in the respiratory system is available. We investigated the effects of a prevalent cyanotoxin, microcystin-LR (MC-LR), using respiratory system-relevant human bronchial epithelial (HBE) cells. The expression of specific organic-anion-transporting polypeptides was evaluated, and the western blot analysis revealed the formation and accumulation of MC-LR protein adducts in exposed cells. However, MC-LR up to 20 μM neither caused significant cytotoxic effects according to multiple viability endpoints after 48-h exposure, nor reduced impedance (cell layer integrity) over 96 h. Time-dependent increase of putative MC-LR adducts with protein phosphatases was not associated with activation of mitogen-activated protein kinases ERK1/2 and p38 during 48-h exposure in HBE cells. Future studies addressing human health risks associated with inhalation of toxic cyanobacteria and cyanotoxins should focus on complex environmental samples of cyanobacterial blooms and alterations of additional non-cytotoxic endpoints while adopting more advanced in vitro models.

• MeSH
• bronchy cytologie   MeSH
• buněčné linie MeSH
• epitelové buňky účinky léků   metabolismus   MeSH
• extracelulárním signálem regulované MAP kinasy metabolismus   MeSH
• lidé MeSH
• mikrocystiny toxicita   MeSH
• mitogenem aktivované proteinkinasy p38 metabolismus   MeSH
• mořské toxiny toxicita   MeSH
• přenašeče organických aniontů genetika   MeSH
• signální transdukce účinky léků   MeSH
• viabilita buněk účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: Renal hypouricemia is a rare heterogeneous inherited disorder characterized by impaired tubular uric acid transport, reabsorption insufficiency and /or acceleration of secretion. The affected individuals are predisposed to nephrolithiasis and recurrent episodes of exercise-induced acute kidney injury. Type 1 is caused by dysfunctional variants in the SLC22A12 gene (URAT1), while type 2 is caused by defects in the SLC2A9 gene (GLUT9). To date, more than 150 patients with the loss-of-function mutations for the SLC22A12 gene have been found (compound heterozygotes and/or homozygotes), most of whom are Japanese and Koreans. CASE PRESENTATION: Herein, we report a nine year old Sri Lankan boy with renal hypouricemia (serum uric acid 97 μmol/L, fractional excretion of uric acid 33%).The sequencing analysis of SLC22A12 revealed a potentially deleterious missense variant c.1400C > T (p.T467 M, rs200104135) in heterozygous state. This variant has been previously identified in homozygous and/or compound heterozygous state with other causative SLC22A12 variant c.1245_1253del (p.L415_G417del) in Roma population. CONCLUSIONS: This is the first identification of a family with mild renal hypouricemia1 associated to the p.T467 M variant. Detailed investigations of urate blood and urine concentrations in patients with unexplained hypouricemia are needed and renal hypouricemia should also be considered in patients other than those from Japan and/or Korea. Our finding confirms an uneven geographical and ethnic distribution of Romany prevalent SLC22A12 variant that need to be considered in Asian patients (population data Genome Aggregation Database: allele frequency in South Asia 0.007055, in East Asia 0.001330).

• MeSH
• dítě MeSH
• dospělí MeSH
• heterozygot * MeSH
• lidé MeSH
• missense mutace * MeSH
• mladiství MeSH
• močové kameny genetika   MeSH
• předškolní dítě MeSH
• přenašeče organických aniontů genetika   MeSH
• proteiny přenášející organické kationty genetika   MeSH
• vrozené poruchy tubulárního transportu genetika   MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Srí Lanka MeSH

Membrane organic anion-transporting polypeptides (OATPs) are responsible for the drug transmembrane transport within the human body. The function of OATP2B1 transporter can be inhibited by various natural compounds. Despite increased research interest in soya as a part of human diet, the effect of its active components to interact with hOATP2B1 has not been elucidated in a complex extent. This in vitro study examined the inhibitory effect of main soy isoflavones (daidzin, daidzein, genistin, genistein, glycitin, glycitein, biochanin A, formononetin) and their metabolites formed in vivo (S-equol, O-desmethylangolensin) towards human OATP2B1 transporter. MDCKII cells overexpressing hOATP2B1 were employed to determine quantitative inhibitory parameters of the tested compounds and to analyze mechanism/s of the inhibitory interaction. The study showed that aglycones of soy isoflavones and the main biologically active metabolite S-equol were able to significantly inhibit hOATP2B1-mediated transport. The Ki values for most of aglycones range from 1 to 20 μM. In contrast, glucosides did not exhibit significant inhibitory effect. The kinetic analysis did not indicate a uniform type of inhibition towards the hOATP2B1 although predominant mechanism of inhibition seemed to be competitive. These findings may suggest that tested soy isoflavones and their metabolites might affect transport of xenobiotics including drugs across tissue barriers via hOATP2B1.

• MeSH
• buňky MDCK MeSH
• Glycine max * MeSH
• isoflavony farmakologie   MeSH
• kinetika MeSH
• přenašeče organických aniontů antagonisté a inhibitory   genetika   metabolismus   MeSH
• psi MeSH
• transfekce MeSH
• zvířata MeSH
• Check Tag
• psi MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• akutní poškození ledvin krev   prevence a kontrola   moč   MeSH
• alopurinol aplikace a dávkování   MeSH
• antioxidancia aplikace a dávkování   MeSH
• cystinóza krev   diagnóza   moč   MeSH
• diferenciální diagnóza MeSH
• dítě MeSH
• Fanconiho syndrom krev   diagnóza   moč   MeSH
• genetické testování MeSH
• kyselina močová krev   metabolismus   moč   MeSH
• ledvinové kanálky metabolismus   MeSH
• lidé MeSH
• močové kameny krev   diagnóza   genetika   moč   MeSH
• přenašeče organických aniontů genetika   MeSH
• proteiny přenášející organické kationty genetika   MeSH
• proteiny usnadňující transport glukosy genetika   MeSH
• renální reabsorpce MeSH
• syndrom nepřiměřené sekrece ADH krev   diagnóza   moč   MeSH
• vrozené poruchy tubulárního transportu krev   diagnóza   genetika   moč   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH

BACKGROUND: Renal hypouricemia (RHUC), a rare inherited disorder characterized by impaired uric acid (UA) reabsorption in the proximal tubule, is caused by mutations in SLC22A12 or SLC2A9. Most mutations have been identified in Japanese patients, and only a few have been detected in Europeans. METHODS: We report clinical, biochemical and genetics findings of fourteen Spanish patients, six Caucasians and eight of Roma ethnia, diagnosed with idiopathic RHUC. Two of the patients presented exercise-induced acute renal failure and another one had several episodes of nephrolithiasis and four of them had progressive deterioration of renal function, while the rest were asymptomatic. RESULTS: Molecular analysis revealed SLC22A12 mutations in ten of the patients, and SLC2A9 mutations in the other four. A new heterozygous SLC22A12 missense mutation, c.1427C>A (p.A476D), was identified in two affected members of the same family. The rest of the patients presented homozygous, heterozygous or compound heterozygous mutations that have been previously identified in patients with RHUC; SLC22A12 p.T467M and p.L415_G417del, and SLC2A9 p.T125M. Expression studies in Xenopus oocytes revealed that c.1427C>A reduced UA transport but did not alter the location of URAT1 protein on the plasma membrane. CONCLUSIONS: The biochemical and clinical features of our patients together with the genetic analysis results confirmed the diagnosis of RHUC. This is the first report describing SLC22A12 and SLC2A9 mutations in Spanish patients.

• MeSH
• dítě MeSH
• dospělí MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• močové kameny genetika   MeSH
• mutace * MeSH
• předškolní dítě MeSH
• přenašeče organických aniontů genetika   MeSH
• proteiny přenášející organické kationty genetika   MeSH
• proteiny usnadňující transport glukosy genetika   MeSH
• rodokmen MeSH
• senioři MeSH
• vrozené poruchy tubulárního transportu genetika   MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Španělsko MeSH