ABCG2 transporter plays a key role in the biodistribution of melatonin and its main metabolites.

The ATP-binding cassette G2 (ABCG2) is an efflux transporter expressed in the apical membrane of cells from a large number of tissues, directly affecting bioavailability, tissue accumulation, and secretion into milk of both xenobiotics and endogenous compounds. The aim of this work was to characterize the role of ABCG2 in the systemic distribution and secretion into milk of melatonin and its main metabolites, 6-hydroxymelatonin, and 6-sulfatoxymelatonin. For this purpose, we first showed that these three molecules are transported by this transporter using in vitro transepithelial assays with MDCK-II polarized cells transduced with different species variants of ABCG2. Second, we tested the in vivo effect of murine Abcg2 in the systemic distribution of melatonin and its metabolites using wild-type and Abcg2-/- mice. Our results show that after oral administration of melatonin, the plasma concentration of melatonin metabolites in Abcg2-/-  mice was between 1.5 and 6-fold higher compared to the wild-type mice. We also evaluated in these animals differences in tissue accumulation of melatonin metabolites. The most relevant differences between both types of mice were found for small intestine and kidney (>sixfold increase for 6-sulfatoxymelatonin in Abcg2-/-  mice). Finally, melatonin secretion into milk was also affected by the murine Abcg2 transporter, with a twofold higher milk concentration in wild-type compared with Abcg2-/-  lactating female mice. In addition, melatonin metabolites showed a higher milk-to-plasma ratio in wild-type mice. Overall, our results show that the ABCG2 transporter plays a critical role in the biodistribution of melatonin and its main metabolites, thereby potentially affecting their biological and therapeutic activity.

Ivermectin inhibits ovine ABCG2-mediated in vitro transport of meloxicam and reduces its secretion into milk in sheep.

The ATP-binding cassette transporter G2 (ABCG2) is an efflux protein involved in the bioavailability and secretion into milk of several compounds including anti-inflammatory drugs. The aim of this work was to determine the effect in sheep of an ABCG2 inhibitor, such as the macrocyclic lactone ivermectin, on the secretion into milk of meloxicam, a non-steroidal anti-inflammatory drug widely used in veterinary medicine, and recently reported as an ABCG2 substrate. In vitro meloxicam transport assays in ovine ABCG2-transduced cells have shown that ivermectin is an efficient inhibitor of in vitro transport of meloxicam mediated by ovine ABCG2, with a 75% inhibition in the transport ratio (24.85 ± 4.62 in controls vs 6.31 ± 1.37 in presence of ivermectin). In addition, the role of ovine ABCG2 in secretion into milk of meloxicam was corroborated using Assaf lactating sheep coadministered with ivermectin. Animals were administered subcutaneously with meloxicam (0.5 mg/kg) with or without ivermectin (0.2 mg/kg). No difference in plasma pharmacokinetic parameters was found between treatments. In the case of milk, a significant reduction in the area under concentration-time curve (AUC) (3.92 ± 0.66 vs 2.26 ± 1.52 µg·h/mL) and the AUC milk-to-plasma ratio (0.17 ± 0.03 vs 0.09 ± 0.06) was reported for ivermectin-treated animals compared to controls.

Secretion into Milk of the Main Metabolites of the Anthelmintic Albendazole Is Mediated by the ABCG2/BCRP Transporter.

Albendazole (ABZ) is an anthelmintic with a broad-spectrum activity, widely used in human and veterinary medicine. ABZ is metabolized in all mammalian species to albendazole sulfoxide (ABZSO), albendazole sulfone (ABZSO2) and albendazole 2-aminosulphone (ABZSO2-NH2). ABZSO and ABZSO2 are the main metabolites detected in plasma and all three are detected in milk. The ATP-binding cassette transporter G2 (ABCG2) is an efflux transporter that is involved in the active secretion of several compounds into milk. Previous studies have reported that ABZSO was in vitro transported by ABCG2. The aim of this work is to correlate the in vitro interaction between ABCG2 and the other ABZ metabolites with their secretion into milk by this transporter. Using in vitro transepithelial assays with cells transduced with murine Abcg2 and human ABCG2, we show that ABZSO2 and ABZSO2-NH2 are in vitro substrates of both. In vivo assays carried out with wild-type and Abcg2-/- lactating female mice demonstrated that secretion into milk of these ABZ metabolites was mediated by Abcg2. Milk concentrations and milk-to-plasma ratio were higher in wild-type compared to Abcg2-/- mice for all the metabolites tested. We conclude that ABZ metabolites are undoubtedly in vitro substrates of ABCG2 and actively secreted into milk by ABCG2.

Role of the Abcg2 transporter in plasma levels and tissue accumulation of the anti-inflammatory tolfenamic acid in mice.

The Breast Cancer Resistance Protein (BCRP/ABCG2) is an ATP-binding cassette efflux transporter that is expressed in the apical membrane of cells from relevant tissues involved in drug pharmacokinetics such as liver, intestine, kidney, testis, brain and mammary gland, among others. Tolfenamic acid is an anti-inflammatory drug used as an analgesic and antipyretic in humans and animals. Recently, tolfenamic acid has been repurposed as an antitumoral drug and for use in chronic human diseases such as Alzheimer. The aim of this work was to study whether tolfenamic acid is an in vitro Abcg2 substrate, and to investigate the potential role of Abcg2 in plasma exposure, secretion into milk and tissue accumulation of this drug. Using in vitro transepithelial assays with cells transduced with Abcg2, we showed that tolfenamic acid is an in vitro substrate of Abcg2. The in vivo effect of this transporter was tested using wild-type and Abcg2-/- mice, showing that after oral and intravenous administration of tolfenamic acid, its area under the plasma concentration-time curve in Abcg2-/- mice was between 1.7 and 1.8-fold higher compared to wild-type mice. Abcg2-/- mice also showed higher liver and testis accumulation of tolfenamic acid after intravenous administration. In this study, we demonstrate that tolfenamic acid is transported in vitro by Abcg2 and that its plasma levels as well as its tissue distribution are affected by Abcg2, with potential pharmacological and toxicological consequences.

Role of eprinomectin as inhibitor of the ruminant ABCG2 transporter: Effects on plasma distribution of danofloxacin and meloxicam in sheep.

Therapeutic outcome results of the coadministration of several drugs in veterinary medicine is affected by, among others, the relationship between drugs and ATP-binding cassette (ABC) transporters, such as ABCG2. ABCG2 is an efflux protein involved in the bioavailability and milk secretion of drugs. The aim of this work was to determine the role of eprinomectin, a macrocyclic lactone (ML) member of avermectin class, as inhibitor of ABCG2. The experiments were carried out through in vitro inhibition assays based on mitoxantrone accumulation and transport assays in ovine ABCG2 transduced cells using the antimicrobial drug danofloxacin and the anti-inflammatory drug meloxicam, both widely used in veterinary medicine and well known ABCG2 substrates. The inhibition results obtained showed that eprinomectin was an efficient in vitro ABCG2 inhibitor, tested in mitoxantrone accumulation assays. In addition, this ML decreased ovine ABCG2-mediated transport of danofloxacin and meloxicam. To evaluate the role of eprinomectin in systemic exposure of drugs, pharmacokinetic assays based on subcutaneous coadministration of eprinomectin with danofloxacin (1.25 mg/kg) or meloxicam (0.5 mg/kg) in sheep were performed obtaining a significant increase of systemic exposure of these drugs. Especially relevant was the increase of the systemic concentration of meloxicam, since coadministration with eprinomectin increased significantly the plasma concentration of meloxicam, obtaining an increase of AUC (0-72 h) value of more than 40%.

Analysis of the interaction between tryptophan-related compounds and ATP-binding cassette transporter G2 (ABCG2) using targeted metabolomics.

ATP-binding cassette transporter G2 (ABCG2) is involved in the secretion of several compounds in milk. The in vitro and in vivo interactions between tryptophan-related compounds and ABCG2 were investigated. The tryptophan metabolome was determined by liquid chromatography-tandem mass spectrometry in milk and plasma from wild-type and Abcg2-/- mice as well as dairy cows carrying the ABCG2 Y581S polymorphism (Y/S) and noncarrier animals (Y/Y). The milk-to-plasma ratios of tryptophan, kynurenic acid, kynurenine, anthranilic acid, and xanthurenic acid were higher in wild-type mice than in Abcg2-/- mice. The ratio was 2-fold higher in Y/S than in Y/Y cows for kynurenine. In vitro transport assays confirmed that some of these compounds were in vitro substrates of the transporter and validated the differences observed between the two variants of the bovine protein. These findings show that the secretion of metabolites belonging to the kynurenine pathway into milk is mediated by ABCG2.

Quantitative Impact of the 2018 American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) Practice Guideline Update on Human Epidermal Growth Factor Receptor 2 Testing in Breast Cancer: A Systematic Analysis.

CONTEXT.­: The global impact of the new 2018 American Society of Clinical Oncology/College of American Pathologists human epidermal growth factor receptor 2 (HER2) practice guideline update on the overall HER2 status designation, compared with the prior 2013 iteration, is unknown. OBJECTIVES.­: To report the quantitative impact of the new guideline on HER2 status distribution. DESIGN.­: The analysis comprised a retrospective cohort of patients from the authors' institution, combined with other peer-reviewed publications that assessed the impact of the 2018 guideline in relation to the 2013 guideline. RESULTS.­: Our study revealed that the new guideline led to an average 9% reclassification rate for the overall HER2 status, with a net gain in overall HER2 negative designation. This is largely due to reclassification of the equivocal (Group 4) groups. Unexpectedly, infrequent but consistent discordance between Group 1/5 and fluorescence in situ hybridization results are observed across studies (1.8%; 73 of 3965 cases where fluorescence in situ hybridization and immunohistochemistry are both reported). CONCLUSIONS.­: Early clinical recognition of these resultant changes, including emerging issues of tumor heterogeneity, and potential discordance between immunohistochemistry to fluorescence in situ hybridization, is important for accurate clinical assessment of individual HER2 test results.

Abcg2 transporter affects plasma, milk and tissue levels of meloxicam.

ATP-binding cassette (ABCG2) is an efflux transporter that extrudes xenotoxins from cells in liver, intestine, mammary gland, brain and other organs, affecting the pharmacokinetics, brain accumulation and secretion into milk of several compounds, including antitumoral, antimicrobial and anti-inflammatory drugs. The aim of this study was to investigate whether the widely used anti-inflammatory drug meloxicam is an Abcg2 sustrate, and how this transporter affects its systemic distribution. Using polarized ABCG2-transduced cell lines, we found that meloxicam is efficiently transported by murine Abcg2 and human ABCG2. After oral administration of meloxicam, the area under the plasma concentration-time curve in Abcg2-/- mice was 2-fold higher than in wild type mice (146.06 ± 10.57 µg·h/ml versus 73.80 ± 10.00 µg·h/ml). Differences in meloxicam distribution were reported for several tissues after oral and intravenous administration, with a 20-fold higher concentration in the brain of Abcg2-/- after oral administration. Meloxicam secretion into milk was also affected by the transporter, with a 2-fold higher milk-to-plasma ratio in wild-type compared with Abcg2-/- lactating female mice after oral and intravenous administration. We conclude that Abcg2 is an important determinant of the plasma and brain distribution of meloxicam and is clearly involved in its secretion into milk.

Transporters in the Mammary Gland-Contribution to Presence of Nutrients and Drugs into Milk.

A large number of nutrients and bioactive ingredients found in milk play an important role in the nourishment of breast-fed infants and dairy consumers. Some of these ingredients include physiologically relevant compounds such as vitamins, peptides, neuroactive compounds and hormones. Conversely, milk may contain substances-drugs, pesticides, carcinogens, environmental pollutants-which have undesirable effects on health. The transfer of these compounds into milk is unavoidably linked to the function of transport proteins. Expression of transporters belonging to the ATP-binding cassette (ABC-) and Solute Carrier (SLC-) superfamilies varies with the lactation stages of the mammary gland. In particular, Organic Anion Transporting Polypeptides 1A2 (OATP1A2) and 2B1 (OATP2B1), Organic Cation Transporter 1 (OCT1), Novel Organic Cation Transporter 1 (OCTN1), Concentrative Nucleoside Transporters 1, 2 and 3 (CNT1, CNT2 and CNT3), Peptide Transporter 2 (PEPT2), Sodium-dependent Vitamin C Transporter 2 (SVCT2), Multidrug Resistance-associated Protein 5 (ABCC5) and Breast Cancer Resistance Protein (ABCG2) are highly induced during lactation. This review will focus on these transporters overexpressed during lactation and their role in the transfer of products into the milk, including both beneficial and harmful compounds. Furthermore, additional factors, such as regulation, polymorphisms or drug-drug interactions will be described.

Role of ABCG2 in Secretion into Milk of the Anti-Inflammatory Flunixin and Its Main Metabolite: In Vitro-In Vivo Correlation in Mice and Cows.

Flunixin meglumine is a nonsteroidal anti-inflammatory drug (NSAID) widely used in veterinary medicine. It is indicated to treat inflammatory processes, pain, and pyrexia in farm animals. In addition, it is one of the few NSAIDs approved for use in dairy cows, and consequently gives rise to concern regarding its milk residues. The ABCG2 efflux transporter is induced during lactation in the mammary gland and plays an important role in the secretion of different compounds into milk. Previous reports have demonstrated that bovine ABCG2 Y581S polymorphism increases fluoroquinolone levels in cow milk. However, the implication of this transporter in the secretion into milk of anti-inflammatory drugs has not yet been studied. The objective of this work was to study the role of ABCG2 in the secretion into milk of flunixin and its main metabolite, 5-hydroxyflunixin, using Abcg2(-/-) mice, and to investigate the implication of the Y581S polymorphism in the secretion of these compounds into cow milk. Correlation with the in vitro situation was assessed by in vitro transport assays using Madin-Darby canine kidney II cells overexpressing murine and the two variants of the bovine transporter. Our results show that flunixin and 5-hydroxyflunixin are transported by ABCG2 and that this protein is responsible for their secretion into milk. Moreover, the Y581S polymorphism increases flunixin concentration into cow milk, but it does not affect milk secretion of 5-hydroxyflunixin. This result correlates with the differences in the in vitro transport of flunixin between the two bovine variants. These findings are relevant to the therapeutics of anti-inflammatory drugs.

Secreted protein extract analyses present the plant pathogen Alternaria alternata as a suitable industrial enzyme toolbox.

Lignocellulosic plant biomass is the most abundant carbon source in the planet, which makes it a potential substrate for biorefinery. It consists of polysaccharides and other molecules with applications in pharmaceutical, food and feed, cosmetics, paper and textile industries. The exploitation of these resources requires the hydrolysis of the plant cell wall, which is a complex process. Aiming to discover novel fungal natural isolates with lignocellulolytic capacities, a screening for feruloyl esterase activity was performed in samples taken from different metal surfaces. An extracellular enzyme extract from the most promising candidate, the natural isolate Alternaria alternata PDA1, was analyzed. The feruloyl esterase activity of the enzyme extract was characterized, determining the pH and temperature optima (pH 5.0 and 55-60 °C, respectively), thermal stability and kinetic parameters, among others. Proteomic analyses derived from two-dimensional gels allowed the identification and classification of 97 protein spots from the extracellular proteome. Most of the identified proteins belonged to the carbohydrates metabolism group, particularly plant cell wall degradation. Enzymatic activities of the identified proteins (ß-glucosidase, cellobiohydrolase, endoglucanase, ß-xylosidase and xylanase) of the extract were also measured. These findings confirm A. alternata PDA1 as a promising lignocellulolytic enzyme producer. SIGNIFICANCE: Although plant biomass is an abundant material that can be potentially utilized by several industries, the effective hydrolysis of the recalcitrant plant cell wall is not a straightforward process. As this hydrolysis occurs in nature relying almost solely on microbial enzymatic systems, it is reasonable to infer that further studies on lignocellulolytic enzymes will discover new sustainable industrial solutions. The results included in this paper provide a promising fungal candidate for biotechnological processes to obtain added value from plant byproducts and analogous substrates. Moreover, the proteomic analysis of the secretome of a natural isolate of Alternaria sp. grown in the presence of one of the most used vegetal substrates on the biofuels industry (sugar beet pulp) sheds light on the extracellular enzymatic machinery of this fungal plant pathogen, and can be potentially applied to developing new industrial enzymatic tools. This work is, to our knowledge, the first to analyze in depth the secreted enzyme extract of the plant pathogen Alternaria when grown on a lignocellulosic substrate, identifying its proteins by means of MALDI-TOF/TOF mass spectrometry and characterizing its feruloyl esterase, cellulase and xylanolytic activities.

Imitation of novel conspecific and human speech sounds in the killer whale (Orcinus orca).

Vocal imitation is a hallmark of human spoken language, which, along with other advanced cognitive skills, has fuelled the evolution of human culture. Comparative evidence has revealed that although the ability to copy sounds from conspecifics is mostly uniquely human among primates, a few distantly related taxa of birds and mammals have also independently evolved this capacity. Remarkably, field observations of killer whales have documented the existence of group-differentiated vocal dialects that are often referred to as traditions or cultures and are hypothesized to be acquired non-genetically. Here we use a do-as-I-do paradigm to study the abilities of a killer whale to imitate novel sounds uttered by conspecific (vocal imitative learning) and human models (vocal mimicry). We found that the subject made recognizable copies of all familiar and novel conspecific and human sounds tested and did so relatively quickly (most during the first 10 trials and three in the first attempt). Our results lend support to the hypothesis that the vocal variants observed in natural populations of this species can be socially learned by imitation. The capacity for vocal imitation shown in this study may scaffold the natural vocal traditions of killer whales in the wild.

Carbohydrate reserves in the facilitator cushion plant Laretia acaulis suggest carbon limitation at high elevation and no negative effects of beneficiary plants.

The elevational range of the alpine cushion plant Laretia acaulis (Apiaceae) comprises a cold upper extreme and a dry lower extreme. For this species, we predict reduced growth and increased non-structural carbohydrate (NSC) concentrations (i.e. carbon sink limitation) at both elevational extremes. In a facilitative interaction, these cushions harbor other plant species (beneficiaries). Such interactions appear to reduce reproduction in other cushion species, but not in L. acaulis. However, vegetative effects may be more important in this long-lived species and may be stronger under marginal conditions. We studied growth and NSC concentrations in leaves and stems of L. acaulis collected from cushions along its full elevational range in the Andes of Central Chile. NSC concentrations were lowest and cushions were smaller and much less abundant at the highest elevation. At the lowest elevation, NSC concentrations and cushion sizes were similar to those of intermediate elevations but cushions were somewhat less abundant. NSC concentrations and growth did not change with beneficiary cover at any elevation. Lower NSC concentrations at the upper extreme contradict the sink-limitation hypothesis and may indicate that a lack of warmth is not limiting growth at high-elevation. At the lower extreme, carbon gain and growth do not appear more limiting than at intermediate elevations. The lower population density at both extremes suggests that the regeneration niche exerts important limitations to this species' distribution. The lack of an effect of beneficiaries on reproduction and vegetative performance suggests that the interaction between L. acaulis and its beneficiaries is probably commensalistic.

Comparison of biological fitness in crosses between subspecies of Meccus phyllosomus (Hemiptera: Reduviidae: Triatominae) in southern Mexico.

Understanding the biological parameters of some triatomine subspecies of Meccus phyllosomus (Burmeister) is a crucial first step in estimating the epidemiologic importance of this group. Biological parameters related to hatching, lifetime, number of blood meals to molt, percentage of females at the end of the cycle, number of laid eggs, and mortality for each instar of 3 M. phyllosomus subspecies [M. p. mazzottii (Usinger), M. p. pallidipennis (Stål), and M. p. phyllosomus] and their laboratory hybrids were evaluated and compared. No significant differences (P > 0.05) were found among the experimental hybrids (MaPa, MaPhy, PaPhy) and reciprocal cohorts. In 5 (hatching, number of blood meals to molt, accumulative mortality, percentage of females, and mean number of laid eggs) of the 6 studied parameters (with the exception of development time), the hybrid cohorts had better fitness results than the parental cohorts involved in each set of crosses. The increase in hybrid fitness found in our study could lead to an increase in the epidemiologic risks caused by transmission of Trypanosoma cruzi to humans.

Proximal End Root Morphology Characteristics in Antemortem Anagen Head Hairs.

The proximal end morphology of antemortem anagen head hair was compared with the characteristics documented to occur in postmortem hairs. Antemortem anagen and telogen head hairs (N = 967) were recovered following exposure to seven environments. Root morphology characteristics consistent with those reported in postmortem hairs were observed in 66 (14%) hairs exposed to a water, normal saline, outdoor soil, or indoor shower environment. Thirty-three anagen hairs (7%) exhibited a root band at the proximal end. The mean distance from the root tip to the onset of the root band ranged from 0.23 to 0.7 mm, depending on the environment. The mean distance from the root tip to the onset of the root band was 0.46 mm, with a mean band length of 0.44 mm. The results illustrate the need to better characterize postmortem banding through quantitative measurements, including the range for root tip to band distance and the overall band length.

Importance of Hybrids of Meccus phyllosomus mazzottii, and M. p. pallidipennis, and M. p. phyllosomus to the Transmission of Trypanosoma cruzi in Mexico.

The time interval before beginning feeding, feeding time, and defecation delay for 3 Triatominae subspecies, Meccus phyllosomus mazzottii (Ma), M. p. pallidipennis (Pa), and M. p. phyllosomus (Phy) and their laboratory hybrids were evaluated. The mean time interval for beginning feeding was between 0.1 and 10.1 min for all nymphal instars in each cohort, with significant (P < 0.05) differences among hybrids and parental cohorts. Four (both MaPa and MaPhy) hybrid cohorts had similar mean feeding times to that recorded for one of their parental subspecies, but shorter than the other, whereas the remaining hybrid cohorts (both PaPhy) had longer feeding times than did both of their parental subspecies. The specimens of MaPa defecated later than the respective instars on their parental subspecies, whereas most instars of the remaining 4 hybrid cohorts (MaPhy and PaPhy) defecated earlier than the respective instars of M. p. phyllosomus. Between 40% and 50% of the defecation events occurred when feeding in MaPhy and PaPhy hybrid cohorts. Given these results, the hybrid cohorts were more effective vectors of Trypanosoma cruzi than their parental subspecies, which could indicate a potentially higher risk of transmission of T. cruzi to reservoir hosts.

Integrating medical and research information: a big data approach.

Most of the information collected in different fields by Instituto de Investigación Biomédica de A Coruña (INIBIC) is classified as unstructured due to its high volume and heterogeneity. This situation, linked to the recent requirement of integrating it to the medical information, makes it necessary to implant specific architectures to collect and organize it before it can be analysed. The purpose of this article is to present the Hadoop framework as a solution to the problem of integrating research information in the Business Intelligence field. This framework can collect, explore, process and structure the aforementioned information, which allow us to develop an equivalent function to a data mart in an Intelligence Business system.

ISO 13606 based system for biomedical parameter storage, querying and alarm detection.

ACHEGAMED is an unsupervised real-time patient monitoring system, with the goal of decreasing the exam and diagnosis time of the most prevalent diseases in today's healthcare services. We developed, as a component of ACHEGAMED, a system for storing a wide range of biomedical parameters as ISO 13606 extracts. The system is able to detect clinical alarms in those parameters and communicate them, if needed, to the appropriate medical staff. Although a component of ACHEGAMED, it can be integrated in other systems in a semantic interoperable way thanks to the ISO 13606 standard, allowing the continuity of patient care.