RESUMEN
Introduction Thrombotic Thrombocytopenic Purpura (TTP) is a rare but life-threatening disorder caused by severely reduced activity of ADAMTS13, causing platelet adhesion and formation of small-vessel platelet-rich thrombi, thrombocytopenia, and microangiopathic haemolytic anaemia. Diagnosis A 48-year-old female presented with acute generalized petechial rash, bruises, and fatigue. Bloods revealed thrombocytopenia, anaemia, 10% schistocytes. Her plasmic score was seven, and ADAMT13 was <5. Treatment Patient initially responded to plasma exchange and steroids, but thrombocytopenia recurred on day six of treatment, needing the addition of further immunosuppressive drugs and Caplacizumab. Conclusion TTP cases unresponsive to conventional regimens can represent a challenging situation; however, poor outcomes could potentially be avoided with a novel therapy like Caplacizumab. In our patient, this medication was well tolerated, and platelet count normalized after two days of its introduction.
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Púrpura Trombocitopénica Trombótica , Anticuerpos de Dominio Único , Humanos , Femenino , Persona de Mediana Edad , Púrpura Trombocitopénica Trombótica/diagnóstico , Púrpura Trombocitopénica Trombótica/tratamiento farmacológico , Anticuerpos de Dominio Único/efectos adversos , Intercambio PlasmáticoRESUMEN
ROHs are long stretches of DNA homozygous at each polymorphic position. The proportion of genome covered by ROHs and their length are indicators of the level and origin of inbreeding. Frequent common ROHs within the same population define ROH islands and indicate hotspots of selection. In this work, we investigated ROHs in a total of 1131 pigs from 20 European local pig breeds and in three cosmopolitan breeds, genotyped with the GGP Porcine HD Genomic Profiler. plink software was used to identify ROHs. Size classes and genomic inbreeding parameters were evaluated. ROH islands were defined by evaluating different thresholds of homozygous SNP frequency. A functional overview of breed-specific ROH islands was obtained via over-representation analyses of GO biological processes. Mora Romagnola and Turopolje breeds had the largest proportions of genome covered with ROH (~1003 and ~955 Mb respectively), whereas Nero Siciliano and Sarda breeds had the lowest proportions (~207 and 247 Mb respectively). The highest proportion of long ROH (>16 Mb) was in Apulo-Calabrese, Mora Romagnola and Casertana. The largest number of ROH islands was identified in the Italian Landrace (n = 32), Cinta Senese (n = 26) and Lithuanian White Old Type (n = 22) breeds. Several ROH islands were in regions encompassing genes known to affect morphological traits. Comparative ROH structure analysis among breeds indicated the similar genetic structure of local breeds across Europe. This study contributed to understanding of the genetic history of the investigated pig breeds and provided information to manage these pig genetic resources.
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Endogamia , Sus scrofa/genética , Animales , Europa (Continente) , Genoma , Genotipo , Homocigoto , Polimorfismo de Nucleótido Simple , Densidad de PoblaciónRESUMEN
In this study, we identified copy number variants (CNVs) in 19 European autochthonous pig breeds and in two commercial breeds (Italian Large White and Italian Duroc) that represent important genetic resources for this species. The genome of 725 pigs was sequenced using a breed-specific DNA pooling approach (30-35 animals per pool) obtaining an average depth per pool of 42×. This approach maximised CNV discovery as well as the related copy number states characterising, on average, the analysed breeds. By mining more than 17.5 billion reads, we identified a total of 9592 CNVs (~683 CNVs per breed) and 3710 CNV regions (CNVRs; 1.15% of the reference pig genome), with an average of 77 CNVRs per breed that were considered as private. A few CNVRs were analysed in more detail, together with other information derived from sequencing data. For example, the CNVR encompassing the KIT gene was associated with coat colour phenotypes in the analysed breeds, confirming the role of the multiple copies in determining breed-specific coat colours. The CNVR covering the MSRB3 gene was associated with ear size in most breeds. The CNVRs affecting the ELOVL6 and ZNF622 genes were private features observed in the Lithuanian Indigenous Wattle and in the Turopolje pig breeds respectively. Overall, the genome variability unravelled here can explain part of the genetic diversity among breeds and might contribute to explain their origin, history and adaptation to a variety of production systems.
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Variaciones en el Número de Copia de ADN , ADN/genética , Sus scrofa/genética , Animales , Cruzamiento , Femenino , Italia , Masculino , Fenotipo , Especificidad de la Especie , Secuenciación Completa del Genoma/veterinariaRESUMEN
Opioids are very effective analgesics, but they are also highly addictive. Methadone is used to treat opioid dependence (OD), acting as a selective agonist at the µ-opioid receptor encoded by the gene OPRM1. Determining the optimal methadone maintenance dose is time consuming; currently, no biomarkers are available to guide treatment. In methadone-treated OD subjects drawn from a case and control sample, we conducted a genome-wide association study of usual daily methadone dose. In African-American (AA) OD subjects (n=383), we identified a genome-wide significant association between therapeutic methadone dose (mean=68.0 mg, s.d.=30.1 mg) and rs73568641 (P=2.8 × 10-8), the nearest gene (306 kilobases) being OPRM1. Each minor (C) allele corresponded to an additional ~20 mg day-1 of oral methadone, an effect specific to AAs. In European-Americans (EAs) (n=1027), no genome-wide significant associations with methadone dose (mean=77.8 mg, s.d.=33.9 mg) were observed. In an independent set of opioid-naive AA children being treated for surgical pain, rs73568641-C was associated with a higher required dose of morphine (n=241, P=3.9 × 10-2). Similarly, independent genomic loci previously shown to associate with higher opioid analgesic dose were associated with higher methadone dose in the OD sample (AA and EA: n=1410, genetic score P=1.3 × 10-3). The present results in AAs indicate that genetic variants influencing opioid sensitivity across different clinical settings could contribute to precision pharmacotherapy for pain and addiction.
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Analgésicos Opioides/farmacología , Trastornos Relacionados con Opioides/genética , Dolor/genética , Adulto , Negro o Afroamericano/genética , Alelos , Analgésicos Opioides/administración & dosificación , Analgésicos Opioides/uso terapéutico , Relación Dosis-Respuesta a Droga , Femenino , Frecuencia de los Genes , Predisposición Genética a la Enfermedad/genética , Estudio de Asociación del Genoma Completo/métodos , Genotipo , Humanos , Masculino , Metadona/uso terapéutico , Persona de Mediana Edad , Morfina/uso terapéutico , Dolor/tratamiento farmacológico , Polimorfismo de Nucleótido Simple/genética , Receptores Opioides mu/genética , Estados Unidos , Población Blanca/genéticaRESUMEN
RNA-Seq technology is widely used in quantitative gene expression studies and identification of non-annotated transcripts. However this technology also can be used for polymorphism detection and RNA editing in transcribed regions in an efficient and cost-effective way. This study used SNP data from an RNA-Seq assay to identify genes and mutations underlying production trait variations in an experimental pig population. The hypothalamic and hepatic transcriptomes of nine extreme animals for growth and fatness from an (Iberian × Landrace) × Landrace backcross were analyzed by RNA-Seq methodology, and SNP calling was conducted. More than 125 000 single nucleotide variants (SNVs) were identified in each tissue, and 78% were considered to be potential SNPs, those SNVs segregating in the context of this study. Potential informative SNPs were detected by considering those showing a homozygous or heterozygous genotype in one extreme group and the alternative genotype in the other group. In this way, 4396 and 1862 informative SNPs were detected in hypothalamus and liver respectively. Out of the 32 SNPs selected for validation, 25 (80%) were confirmed as actual SNPs. Association analyses for growth, fatness and premium cut yields with 19 selected SNPs were carried out, and four potential causal genes (RETSAT, COPA, RNMT and PALMD) were identified. Interestingly, new RNA editing modifications were detected and validated for the NR3C1:g.102797 (ss1985401074) and ACSM2B:g.13374 (ss1985401075) positions and for the COG3:g3.4525 (ss1985401087) modification previously identified across vertebrates, which could lead to phenotypic variation and should be further investigated.
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Carne , Polimorfismo de Nucleótido Simple , Edición de ARN , Análisis de Secuencia de ARN/métodos , Sus scrofa/genética , Animales , Cruzamientos Genéticos , Femenino , Masculino , Sus scrofa/fisiologíaRESUMEN
An increasing number of genetic variants have been implicated in autism spectrum disorders (ASDs), and the functional study of such variants will be critical for the elucidation of autism pathophysiology. Here, we report a de novo balanced translocation disruption of TRPC6, a cation channel, in a non-syndromic autistic individual. Using multiple models, such as dental pulp cells, induced pluripotent stem cell (iPSC)-derived neuronal cells and mouse models, we demonstrate that TRPC6 reduction or haploinsufficiency leads to altered neuronal development, morphology and function. The observed neuronal phenotypes could then be rescued by TRPC6 complementation and by treatment with insulin-like growth factor-1 or hyperforin, a TRPC6-specific agonist, suggesting that ASD individuals with alterations in this pathway may benefit from these drugs. We also demonstrate that methyl CpG binding protein-2 (MeCP2) levels affect TRPC6 expression. Mutations in MeCP2 cause Rett syndrome, revealing common pathways among ASDs. Genetic sequencing of TRPC6 in 1041 ASD individuals and 2872 controls revealed significantly more nonsynonymous mutations in the ASD population, and identified loss-of-function mutations with incomplete penetrance in two patients. Taken together, these findings suggest that TRPC6 is a novel predisposing gene for ASD that may act in a multiple-hit model. This is the first study to use iPSC-derived human neurons to model non-syndromic ASD and illustrate the potential of modeling genetically complex sporadic diseases using such cells.
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Trastorno Autístico/patología , Neuronas/patología , Canales Catiónicos TRPC/metabolismo , Animales , Protocolos de Quimioterapia Combinada Antineoplásica/metabolismo , Trastorno Autístico/genética , Trastorno Autístico/fisiopatología , Carboplatino/metabolismo , Diferenciación Celular/genética , Línea Celular , Proliferación Celular/genética , Células Cultivadas , Niño , Modelos Animales de Enfermedad , Embrión de Mamíferos , Etopósido/metabolismo , Regulación de la Expresión Génica/genética , Humanos , Técnicas In Vitro , Células Madre Pluripotentes Inducidas/fisiología , Potenciales Postsinápticos Inhibidores/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Mitoxantrona/metabolismo , Mutación/genética , Neuronas/metabolismo , Prednisolona/metabolismo , Transducción de Señal/genética , Canales Catiónicos TRPC/genética , Canal Catiónico TRPC6RESUMEN
Iberian pigs and its crosses are produced to obtain high-quality meat products. The objective of this work was to evaluate a wide panel of DNA markers, selected by biological and functional criteria, for association with traits related to muscle growth, fatness, meat quality and metabolism. We used 18 crossbred Iberian pigs with divergent postnatal growth patterns for whole genome sequencing and SNP discovery, with over 13 million variants being detected. We selected 1023 missense SNPs located on annotated genes and showing different allele frequencies between pigs with makerdly different growth patterns. We complemented this panel with 192 candidate SNPs obtained from literature mining and from muscle RNAseq data. The selected markers were genotyped in 480 Iberian × Duroc pigs from a commercial population, in which phenotypes were obtained, and an association study was performed for the 1005 successfully genotyped SNPs showing segregation. The results confirmed the effects of several known SNPs in candidate genes (such as LEPR, ACACA, FTO, LIPE or SCD on fatness, growth and fatty acid composition) and also disclosed interesting effects of new SNPs in less known genes such as LRIG3, DENND1B, SOWAHB, EPHX1 or NFE2L2 affecting body weight, average daily gain and adiposity at different ages, or KRT10, NLE1, KCNH2 or AHNAK affecting fatness and FA composition. The results provide a valuable basis for future implementation of marker-assisted selection strategies in swine and contribute to a better understanding of the genetic architecture of relevant traits.
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Carne , Polimorfismo de Nucleótido Simple , Animales , Ácidos Grasos/genética , Ácidos Grasos/metabolismo , Marcadores Genéticos , Estudio de Asociación del Genoma Completo , Fenotipo , Porcinos/genéticaRESUMEN
Low protein diets supplied during the growing period of pigs can diminish their growth rate and increase the intramuscular fat (IMF) content which affects the sensorial and technological characteristics of the products. In the present study, the effects of a low protein diet supplied during the growing period of Duroc × Iberian crossbred pigs on several phenotypic traits and on liver and longissimus dorsi transcriptome were analysed at the beginning (EARLY) and at the end (LATE) of the growing period. Two experimental groups of 10 crossbred pigs each were fed two isocaloric diets with different protein content: control diet (C) with 16.5% protein and 0.8% lysine and low protein diet (LP) with 11% CP and 0.6% lysine. Animals fed LP diet have a slower growth than those fed C diet, but no effect of LP diet was observed on the IMF content. The transcriptomes of liver and longissimus dorsi were characterised and quantified through RNA-sequencing (RNA-seq). In liver, 134 and 480 differentially expressed annotated genes and new isoforms (DEGs) were detected between C and LP diets for EARLY and LATE animals, respectively. In muscle, 128 and 68 DEGs were detected at EARLY and LATE time-points. Functional interpretation revealed that LP diet may inhibit immune system molecules and processes in both tissues at EARLY stage. In liver, the DEGs mainly affect lipid and cholesterol metabolic processes, while in muscle, the expression changes would be involved in growth, development and meat quality. In conclusion, a low protein diet supplied during the growing period seems to slow down the growth of Duroc × Iberian crossbred pigs, but it also seems to affect multiple biological processes that could compromise the immune system of Duroc × Iberian crossbred pigs. Therefore, these results question the adequacy of this type of regime in Duroc × Iberian pigs that must be studied in greater depth before being implemented.
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Dieta con Restricción de Proteínas , Transcriptoma , Animales , Dieta/veterinaria , Dieta con Restricción de Proteínas/veterinaria , Hígado , Lisina , Carne/análisis , Músculo Esquelético , Porcinos/genéticaRESUMEN
Spanish legislation regulates the labelling of Iberian pig meat and dry-cured products, which are labelled as "Ibérico" or "100% Ibérico" when they come from Duroc x Iberian crossbred or Iberian purebred pigs. Although the analytical authentication of breed origin is not mandatory, a genetic diagnostic tool is demanded by producers and consumers. We have designed a 64 Single Nucleotide Variant genotyping panel displaying extreme allelic frequencies between Duroc and Iberian purebred samples. Average proportions of Iberian alleles of 0.99, 0.01, 0.77 and 0.48 were estimated by admixture clustering analysis of known origin samples, for Iberian and Duroc purebred, 75% Iberian and 50% Iberian classes, respectively. A supervised analysis with 1419 samples showed some overlapping between contiguous classes, but the calculated degrees of separability ranged from 0.800 to 0.996, exceeding the threshold value (0.70) for considering suitable for prediction. Therefore, this panel is a useful genetic tool to infer purebred or crossbred Iberian origin of live animals, meat and dry-cured products.
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Productos de la Carne/análisis , Carne de Cerdo/análisis , Sus scrofa/genética , Animales , Cruzamiento , Polimorfismo de Nucleótido Simple , España , Sus scrofa/clasificaciónRESUMEN
Genetic characterization of local breeds is essential to preserve their genomic variability, to advance conservation policies and to contribute to their promotion and sustainability. Genomic diversity of twenty European local pig breeds and a small sample of Spanish wild pigs was assessed using high density SNP chips. A total of 992 DNA samples were analyzed with the GeneSeek Genomic Profiler (GGP) 70 K HD porcine genotyping chip. Genotype data was employed to compute genetic diversity, population differentiation and structure, genetic distances, linkage disequilibrium and effective population size. Our results point out several breeds, such as Turopolje, Apulo Calabrese, Casertana, Mora Romagnola and Lithuanian indigenous wattle, having the lowest genetic diversity, supported by low heterozygosity and very small effective population size, demonstrating the need of enhanced conservation strategies. Principal components analysis showed the clustering of the individuals of the same breed, with few breeds being clearly isolated from the rest. Several breeds were partially overlapped, suggesting genetic closeness, which was particularly marked in the case of Iberian and Alentejana breeds. Spanish wild boar was also narrowly related to other western populations, in agreement with recurrent admixture between wild and domestic animals. We also searched across the genome for loci under diversifying selection based on FST outlier tests. Candidate genes that may underlie differences in adaptation to specific environments and productive systems and phenotypic traits were detected in potentially selected genomic regions.
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Desequilibrio de Ligamiento/genética , Polimorfismo de Nucleótido Simple/genética , Porcinos/genética , Animales , Animales Domésticos/genética , Cruzamiento/métodos , Variación Genética/genética , Genética de Población/métodos , Genoma , Genómica/métodos , Genotipo , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Fenotipo , Densidad de Población , Análisis de Componente Principal/métodosRESUMEN
A wine model was evaluated to determine the influence of aging on the ability of whole yeast cells (WY) and yeast cell walls (YCW) to remove ochratoxin A (OTA). Aging and autolysis were monitored for 214 h in the model wine. The original concentration of OTA in the model wine was 10 microg/liter, and WY and YCW were added at a final concentration of 1 g/liter. YCW mannoproteins were involved in the removal of OTA from the model wine through adsorption mechanisms. Aging affected the capacity of WY to remove OTA, but YCW removal capacity remained constant during aging. A previous heat treatment (85 degrees C for 10 min) of WY and YCW increased their removal capacity and increased the efficiency of the decontamination process.
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Descontaminación/métodos , Contaminación de Alimentos/análisis , Ocratoxinas/análisis , Saccharomyces cerevisiae/fisiología , Vino/análisis , Adsorción , Autólisis , Calor , Humanos , Microbiología Industrial , Factores de Tiempo , Vitis/química , Vitis/microbiología , Vino/microbiologíaRESUMEN
Two different yeast cell wall extracts were obtained using enzymatic digestion and thermal treatment. The effects of the extracts obtained on the foaming properties of a model wine and two sparkling wines were studied. The model wine and sparkling wines, supplemented with the thermal extract, presented better foaming properties than did the samples supplemented with the enzymatic extract. The fractioning (Con A chromatography) and characterization (SDS-PAGE, SEC, GC, and RP-HPLC) of both extracts showed that the fraction responsible for the foaming properties is constituted by mannoproteins with a relative molecular weight between 10 and 30 kDa, presenting an equilibrated composition of the hydrophobic and hydrophilic protein domains. This thermal extract did not modify the protein stability in both the model wine and the sparkling wines. These results demonstrate that the enrichment of a sparkling wine with mannoproteins extracted by mild heat procedures will contribute to improving its foaming properties.
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Pared Celular/química , Vino/análisis , Levaduras/ultraestructura , Bebidas Gaseosas/análisis , Fenómenos Químicos , Química Física , Cromatografía Líquida de Alta Presión , Electroforesis en Gel de Poliacrilamida , Calor , Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/aislamiento & purificaciónRESUMEN
Diet influences animal body and tissue composition due to direct deposition and to the nutrients effects on metabolism. The influence of specific nutrients on the molecular regulation of lipogenesis is not well characterized and is known to be influenced by many factors including timing and physiological status. A trial was performed to study the effects of different dietary energy sources on lipogenic genes transcription in ham adipose tissue of Iberian pigs, at different growth periods and on feeding/fasting situations. A total of 27 Iberian male pigs of 28 kg BW were allocated to two separate groups and fed with different isocaloric feeding regimens: standard diet with carbohydrates as energy source (CH) or diet enriched with high oleic sunflower oil (HO). Ham subcutaneous adipose tissue was sampled by biopsy at growing (44 kg mean BW) and finishing (100 kg mean BW) periods. The first sampling was performed on fasted animals, while the last sampling was performed twice, with animals fasted overnight and 3 h after refeeding. Effects of diet, growth period and feeding/fasting status on gene expression were explored quantifying the expression of a panel of key genes implicated in lipogenesis and lipid metabolism processes. Quantitative PCR revealed several differentially expressed genes according to diet, with similar results at both timings: RXRG, LEP and FABP5 genes were upregulated in HO group while ME1, FASN, ACACA and ELOVL6 were upregulated in CH. The diet effect on ME1 gene expression was conditional on feeding/fasting status, with the higher ME1 gene expression in CH than HO groups, observed only in fasting samples. Results are compatible with a higher de novo endogenous synthesis of fatty acids (FA) in the carbohydrate-supplemented group and a higher FA transport in the oleic acid-supplemented group. Growth period significantly affected the expression of most of the studied genes, with all but PPARG showing higher expression in finishing pigs according to a pattern dissimilar from the usual in cosmopolitan pig breeds. Feeding/fasting status only influenced PPARG gene transcription. The lack of effects of feeding/fasting status on lipogenic gene expression and the higher ME1 response to diet in fasting samples than in postprandial sampling, suggest the persistence of de novo lipogenesis during fasting. Overall results improve the understanding of the influence of different factors on lipid metabolism regulation in Iberian pigs.
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Tejido Adiposo/efectos de los fármacos , Carbohidratos de la Dieta/farmacología , Metabolismo de los Lípidos/efectos de los fármacos , Metabolismo de los Lípidos/genética , Ácido Oléico/farmacología , Porcinos/genética , Porcinos/metabolismo , Transcripción Genética/efectos de los fármacos , Tejido Adiposo/metabolismo , Animales , Dieta/veterinaria , Suplementos Dietéticos , Ácidos Grasos/metabolismo , Lipogénesis/efectos de los fármacos , Lipogénesis/genética , Masculino , Aceites de Plantas/química , Aceites de Plantas/farmacología , Grasa Subcutánea/metabolismo , Aceite de Girasol , Porcinos/crecimiento & desarrollo , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/genéticaRESUMEN
The phenomenon of herding is a very general feature of the collective behavior of many species in panic conditions, including humans. It has been predicted theoretically that panic-induced herding in individuals confined to a room can produce a nonsymmetrical use of two identical exit doors. Here we demonstrate the existence of that phenomenon in experiments, using ants as a model of pedestrians. We show that ants confined to a cell with two symmetrically located exits use both exits in approximately equal proportions to abandon it in normal conditions but prefer one of the exits if panic is created by adding a repellent fluid. In addition, we are able to reproduce the observed escape dynamics in detail using a modification of a previous theoretical model that includes herding associated with a panic parameter as a central ingredient. Our experimental results, combined with theoretical models, suggest that some features of the collective behavior of humans and ants can be quite similar when escaping under panic.
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Hormigas/fisiología , Conducta Animal , Reacción de Fuga , Conducta Social , Alimentación Animal , Animales , Repelentes de Insectos , Modelos Biológicos , Actividad Motora , Hojas de la Planta , Caminata/fisiologíaRESUMEN
The effect of two diets, respectively enriched with SFA (S) and PUFA (P), on FA tissue composition and gene expression was studied in fattened Iberian pigs. The FA composition of adipose, muscular and liver tissues was affected by dietary treatment. S group showed higher MUFA and MUFA/SFA ratio and lower PUFA and n-6/n-3 ratio than P group in all analyzed tissues. In muscle and liver the extracted lipids were separated into neutral lipids and polar lipid fractions which showed significantly different responses to the dietary treatment, especially in liver where no significant effect of diet was observed in NL fraction. The expression of six candidate genes related to lipogenesis and FA oxidation was analyzed by qPCR. In liver, stearoyl CoA desaturase (SCD), acetyl CoA carboxylase alpha (ACACA) and malic enzyme 1 (ME1) genes showed higher expression in S group. SCD, ACACA, ME1, and fatty acid synthase (FASN) gene expression levels showed a wide variation across the tested tissues, with much higher expression levels observed in adipose tissue than other tissues. Tissue FA profile and gene expression results support the deposition of dietary FA, the lipogenic effect of dietary saturated fat in liver and the employment of saturated dietary fat for endogenous synthesis of MUFA in all the analyzed tissues.
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Dieta/veterinaria , Grasas de la Dieta/administración & dosificación , Ácidos Grasos/análisis , Regulación Enzimológica de la Expresión Génica , Carne/análisis , Aceites de Plantas/administración & dosificación , Animales , Animales Endogámicos , Grasas de la Dieta/metabolismo , Ácidos Grasos/metabolismo , Ácidos Grasos Monoinsaturados/análisis , Ácidos Grasos Monoinsaturados/metabolismo , Lipogénesis , Hígado/química , Hígado/metabolismo , Masculino , Músculo Esquelético/química , Músculo Esquelético/metabolismo , Orquiectomía , Especificidad de Órganos , Aceites de Plantas/metabolismo , España , Grasa Subcutánea Abdominal/química , Grasa Subcutánea Abdominal/metabolismo , Aceite de Girasol , Sus scrofa , Transcripción GenéticaRESUMEN
The substrate specificity at the active site of recombinant human synovial fluid phospholipase A2 (hs-PLA2) was investigated by the preparation of a series of short-chain phospholipid analogs and measurement of their enzymatic hydrolysis at concentrations well below the critical micelle concentration. Substrates used in the study included 1,2-dihexanoylglycerophospholipids, 1,2-bis(alkanoylthio)glycerophospholipids, and 1-O-alkyl-2-(alkanoylthio)phospholipids. Turnover was observed for only a few of the 1,2-dihexanoylglycerophospholipids, and the rate of hydrolysis was very low, near the limit of detection of the assay. In contrast, selected 2-(alkanoylthio)-glycerophospholipids were hydrolyzed by hs-PLA2 at much higher rates at concentrations well below their critical micelle concentration (cmc). Thus, the 1,2-bis(hexanoylthio)glycerophosphatidylmethanol exhibits a k(cat)/K(M) = 1800 L mol-1 s-1. Over the calculated log P (cLogP) range of 3-9, cLogP and log(k(cat)/K(M) were linearly related for compounds with straight-chain sn-1 and sn-2 substituents. At comparable cLogP's, the sn-1 ethers and thioesters were hydrolyzed at comparable rates. A negative charge in the phosphate head group was required for enzyme activity. Unsaturation, aromaticity, and branching in the sn-2 substituent reduce turnover dramatically. The same structural modifications in the sn-1 substituent have less effect on turnover. Certain of these substrates, e.g., 1,2-bis(hexanoylthio)glycerophosphatidylmethanol, may be useful in assaying for active site inhibitors of PLA2. The structure--activity relationships established here for substrates should serve as a reference for the structure--activity relationships of substrate-based inhibitors.
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Fosfolipasas A/antagonistas & inhibidores , Fosfolípidos/metabolismo , Líquido Sinovial/enzimología , Sitios de Unión , Humanos , Modelos Moleculares , Fosfolipasas A/metabolismo , Fosfolipasas A2 , Relación Estructura-Actividad , Especificidad por SustratoRESUMEN
We previously reported the identification of (2S)-((2-benzoylphenyl)amino)-3-¿4-[2-(5-methyl-2-phenyloxazol-4-y l)e thoxy]phenyl¿propanoic acid (2) (PPARgamma pKi = 8.94, PPARgamma pEC50 = 9.47) as a potent and selective PPARgamma agonist. We now report the expanded structure-activity relationship around the phenyl alkyl ether moiety by pursuing both a classical medicinal chemistry approach and a solid-phase chemistry approach for analogue synthesis. The solution-phase strategy focused on evaluating the effects of oxazole and phenyl ring replacements of the 2-(5-methyl-2-phenyloxazol-4-yl)ethyl side chain of 2 with several replacements providing potent and selective PPARgamma agonists with improved aqueous solubility. Specifically, replacement of the phenyl ring of the phenyloxazole moiety with a 4-pyridyl group to give 2(S)-((2-benzoylphenyl)amino)-3-¿4-[2-(5-methyl-2-pyridin-4-yloxazol+ ++- 4-yl)ethoxy]phenyl¿propionic acid (16) (PPARgamma pKi = 8.85, PPARgamma pEC50 = 8.74) or a 4-methylpiperazine to give 2(S)-((2-benzoylphenyl)amino)-3-(4-¿2-[5-methyl-2-(4-methylpiperazin+ ++- 1-yl)thiazol-4-yl]ethoxy¿phenyl)propionic acid (24) (PPARgamma pKi = 8.66, PPARgamma pEC50 = 8.89) provided two potent and selective PPARgamma agonists with increased solubility in pH 7.4 phosphate buffer and simulated gastric fluid as compared to 2. The second strategy took advantage of the speed and ease of parallel solid-phase analogue synthesis to generate a more diverse set of phenyl alkyl ethers which led to the identification of a number of novel, high-affinity PPARgamma ligands (PPARgamma pKi's 6.98-8.03). The combined structure-activity data derived from the two strategies provide valuable insight on the requirements for PPARgamma binding, functional activity, selectivity, and aqueous solubility.
Asunto(s)
Proteínas de Unión al ADN/agonistas , Hipoglucemiantes/síntesis química , Hipolipemiantes/síntesis química , Oxazoles/síntesis química , Propionatos/síntesis química , Receptores Citoplasmáticos y Nucleares/agonistas , Tiazoles/síntesis química , Factores de Transcripción/agonistas , Tirosina/análogos & derivados , Tirosina/síntesis química , Adipocitos/citología , Adipocitos/efectos de los fármacos , Animales , Diferenciación Celular/efectos de los fármacos , Línea Celular , Humanos , Hipoglucemiantes/química , Hipoglucemiantes/farmacología , Hipolipemiantes/química , Hipolipemiantes/farmacología , Ligandos , Lípidos/biosíntesis , Ratones , Oxazoles/química , Oxazoles/farmacología , Propionatos/química , Propionatos/farmacología , Ensayo de Unión Radioligante , Receptores Citoplasmáticos y Nucleares/metabolismo , Proteínas Recombinantes de Fusión/agonistas , Proteínas Recombinantes de Fusión/metabolismo , Solubilidad , Relación Estructura-Actividad , Tiazoles/química , Tiazoles/farmacología , Factores de Transcripción/metabolismo , Transfección , Tirosina/química , Tirosina/farmacologíaRESUMEN
Due to the clinical importance of differentiating the two species of the Entamoeba histolytica/Entamoeba dispar complex, we developed a multiplex polymerase chain reaction (PCR) method that overcomes time-consuming and laborious procedures. We report here a DNA extraction protocol using non-fixed stool samples that avoid long lysis-incubation periods through the combined use of zirconium beads and a lysis-supporting buffer. We characterized 49 of 52 stool specimens from Cuban patients with amoebiosis. Among them, 36 (75.5%) were infected only with E. dispar (the nonpathogenic species), while 13 (24.5%) displayed a mixed infection with both E. dispar and E. histolytica. The multiplex PCR protocol showed a specificity of 1.00 and a sensitivity of 0.94. Furthermore, the entire procedure can be performed in one day. This approach is therefore reliable and applicable in the field for epidemiologic studies.