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1.
Cell Genom ; : 100609, 2024 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-39019033

RESUMEN

Little is known about the role of non-coding regions in the etiology of autism spectrum disorder (ASD). We examined three classes of non-coding regions: human accelerated regions (HARs), which show signatures of positive selection in humans; experimentally validated neural VISTA enhancers (VEs); and conserved regions predicted to act as neural enhancers (CNEs). Targeted and whole-genome analysis of >16,600 samples and >4,900 ASD probands revealed that likely recessive, rare, inherited variants in HARs, VEs, and CNEs substantially contribute to ASD risk in probands whose parents share ancestry, which enriches for recessive contributions, but modestly contribute, if at all, in simplex family structures. We identified multiple patient variants in HARs near IL1RAPL1 and in VEs near OTX1 and SIM1 and showed that they change enhancer activity. Our results implicate both human-evolved and evolutionarily conserved non-coding regions in ASD risk and suggest potential mechanisms of how regulatory changes can modulate social behavior.

2.
J Fish Biol ; 2024 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-38679466

RESUMEN

The migratory behavior of Atlantic salmon (Salmo salar) post-smolts in coastal waters is poorly understood. In this collaborative study, 1914 smolts, from 25 rivers, in four countries were tagged with acoustic transmitters during a single seasonal migration. In total, 1105 post-smolts entered the marine study areas and 438 (39.6%) were detected on a network of 414 marine acoustic receivers and an autonomous underwater vehicle. Migration pathways (defined as the shortest distance between two detections) of up to 575 km and over 100 days at sea were described for all 25 populations. Post-smolts from different rivers, as well as individuals from the same river, used different pathways in coastal waters. Although difficult to generalize to all rivers, at least during the year of this study, no tagged post-smolts from rivers draining into the Irish Sea were detected entering the areas of sea between the Hebrides and mainland Scotland, which is associated with a high density of finfish aquaculture. An important outcome of this study is that a high proportion of post-smolts crossed through multiple legislative jurisdictions and boundaries during their migration. This study provides the basis for spatially explicit assessment of the impact risk of coastal pressures on salmon during their first migration to sea.

3.
Ann Emerg Med ; 83(4): 340-350, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38180403

RESUMEN

STUDY OBJECTIVE: Although an increasing number of emergency departments (ED) offer opioid agonist treatment, naloxone, and other harm reduction measures, little is known about patient perspectives on harm reduction practices delivered in the ED. The objective of this study was to identify patient-focused barriers and facilitators to harm reduction strategies in the ED. METHODS: We conducted semistructured interviews with a convenience sample of individuals in Massachusetts diagnosed with opioid use disorder. We developed an interview guide, and interviews were recorded, transcribed, and analyzed in an iterative process using reflexive thematic analysis. After initial interviews and coding, we triangulated the results among a focus group of 4 individuals with lived experience. RESULTS: We interviewed 25 participants with opioid use disorder, 6 recruited from 1 ED and 19 recruited from opioid agonist treatment clinics. Key themes included accessibility of harm reduction supplies, lack of self-care resulting from withdrawal and hopelessness, the impact of stigma on the likelihood of using harm reduction practices, habit and knowledge, as well as the need for user-centered harm reduction interventions. CONCLUSION: In this study, people with lived experience discussed the characteristics and need for user-centered harm reduction strategies in the ED that centered on reducing stigma, treatment of withdrawal, and availability of harm reduction materials.


Asunto(s)
Reducción del Daño , Trastornos Relacionados con Opioides , Humanos , Analgésicos Opioides/uso terapéutico , Trastornos Relacionados con Opioides/prevención & control , Trastornos Relacionados con Opioides/tratamiento farmacológico , Naloxona/uso terapéutico , Investigación Cualitativa
4.
J Fish Biol ; 104(1): 265-283, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37843923

RESUMEN

The freshwater phase of the first seaward migration of juvenile Atlantic salmon (Salmo salar) is relatively well understood when compared with our understanding of the marine phase of their migration. In 2021, 1008 wild and 60 ranched Atlantic salmon smolts were tagged with acoustic transmitters in 12 rivers in England, Scotland, Northern Ireland and Ireland. Large marine receiver arrays were deployed in the Irish Sea at two locations: at the transition of the Irish Sea into the North Atlantic between Ireland and Scotland, and between southern Scotland and Northern Ireland, to examine the early phase of the marine migration of Atlantic salmon smolts. After leaving their natal rivers' post-smolt migration through the Irish Sea was rapid with minimum speeds ranging from 14.03 to 38.56 km.day-1 for Atlantic salmon smolts that entered the Irish Sea directly from their natal river, to 9.69-39.94 km.day-1 for Atlantic salmon smolts that entered the Irish Sea directly from their natal estuary. Population minimum migration success through the study area was strongly correlated with the distance of travel, populations further away from the point of entry to the open North Atlantic exhibited lower migration success. Post-smolts from different populations experienced different water temperatures on entering the North Atlantic. This was largely driven by the timing of their migration and may have significant consequences for feeding and ultimately survivorship. The influence of water currents on post-smolt movement was investigated using data from previously constructed numerical hydrodynamic models. Modeled water current data in the northern Irish Sea showed that post-smolts had a strong preference for migrating when the current direction was at around 283° (west-north-west) but did not migrate when exposed to strong currents in other directions. This is the most favorable direction for onward passage from the Irish Sea to the continental shelf edge current, a known accumulation point for migrating post-smolts. These results strongly indicate that post-smolts migrating through the coastal marine environment are: (1) not simply migrating by current following (2) engage in active directional swimming (3) have an intrinsic sense of their migration direction and (4) can use cues other than water current direction to orientate during this part of their migration.


Asunto(s)
Ríos , Salmo salar , Animales , Señales (Psicología) , Migración Animal , Agua
5.
medRxiv ; 2023 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-37790480

RESUMEN

Little is known about the role of noncoding regions in the etiology of autism spectrum disorder (ASD). We examined three classes of noncoding regions: Human Accelerated Regions (HARs), which show signatures of positive selection in humans; experimentally validated neural Vista Enhancers (VEs); and conserved regions predicted to act as neural enhancers (CNEs). Targeted and whole genome analysis of >16,600 samples and >4900 ASD probands revealed that likely recessive, rare, inherited variants in HARs, VEs, and CNEs substantially contribute to ASD risk in probands whose parents share ancestry, which enriches for recessive contributions, but modestly, if at all, in simplex family structures. We identified multiple patient variants in HARs near IL1RAPL1 and in a VE near SIM1 and showed that they change enhancer activity. Our results implicate both human-evolved and evolutionarily conserved noncoding regions in ASD risk and suggest potential mechanisms of how changes in regulatory regions can modulate social behavior.

6.
Mol Ecol Resour ; 2023 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-37246351

RESUMEN

The negative genetic impacts of gene flow from domestic to wild populations can be dependent on the degree of domestication and exacerbated by the magnitude of pre-existing genetic differences between wild populations and the domestication source. Recent evidence of European ancestry within North American aquaculture Atlantic salmon (Salmo salar) has elevated the potential impact of escaped farmed salmon on often at-risk wild North American salmon populations. Here, we compare the ability of single nucleotide polymorphism (SNP) and microsatellite (SSR) marker panels of different sizes (7-SSR, 100-SSR and 220K-SNP) to detect introgression of European genetic information into North American wild and aquaculture populations. Linear regression comparing admixture predictions for a set of individuals common to the three datasets showed that the 100-SSR panel and 7-SSR panels replicated the full 220K-SNP-based admixture estimates with low accuracy (r2 of .64 and .49, respectively). Additional tests explored the effects of individual sample size and marker number, which revealed that ~300 randomly selected SNPs could replicate the 220K-SNP admixture predictions with greater than 95% fidelity. We designed a custom SNP panel (301-SNP) for European admixture detection in future monitoring work and then developed and tested a python package, salmoneuadmix (https://github.com/CNuge/SalmonEuAdmix), which uses a deep neural network to make de novo estimates of individuals' European admixture proportion without the need to conduct complete admixture analysis utilizing baseline samples. The results demonstrate the mobilization of targeted SNP panels and machine learning in support of at-risk species conservation and management.

7.
Proc Natl Acad Sci U S A ; 120(4): e2209964120, 2023 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-36669111

RESUMEN

Sonic hedgehog signaling regulates processes of embryonic development across multiple tissues, yet factors regulating context-specific Shh signaling remain poorly understood. Exome sequencing of families with polymicrogyria (disordered cortical folding) revealed multiple individuals with biallelic deleterious variants in TMEM161B, which encodes a multi-pass transmembrane protein of unknown function. Tmem161b null mice demonstrated holoprosencephaly, craniofacial midline defects, eye defects, and spinal cord patterning changes consistent with impaired Shh signaling, but were without limb defects, suggesting a CNS-specific role of Tmem161b. Tmem161b depletion impaired the response to Smoothened activation in vitro and disrupted cortical histogenesis in vivo in both mouse and ferret models, including leading to abnormal gyration in the ferret model. Tmem161b localizes non-exclusively to the primary cilium, and scanning electron microscopy revealed shortened, dysmorphic, and ballooned ventricular zone cilia in the Tmem161b null mouse, suggesting that the Shh-related phenotypes may reflect ciliary dysfunction. Our data identify TMEM161B as a regulator of cerebral cortical gyration, as involved in primary ciliary structure, as a regulator of Shh signaling, and further implicate Shh signaling in human gyral development.


Asunto(s)
Hurones , Proteínas Hedgehog , Animales , Femenino , Humanos , Ratones , Embarazo , Sistema Nervioso Central/metabolismo , Cilios/genética , Cilios/metabolismo , Proteínas Hedgehog/genética , Proteínas Hedgehog/metabolismo , Ratones Noqueados , Transducción de Señal
8.
Dev Cell ; 57(20): 2381-2396.e13, 2022 10 24.
Artículo en Inglés | MEDLINE | ID: mdl-36228617

RESUMEN

Kinesins are canonical molecular motors but can also function as modulators of intracellular signaling. KIF26A, an unconventional kinesin that lacks motor activity, inhibits growth-factor-receptor-bound protein 2 (GRB2)- and focal adhesion kinase (FAK)-dependent signal transduction, but its functions in the brain have not been characterized. We report a patient cohort with biallelic loss-of-function variants in KIF26A, exhibiting a spectrum of congenital brain malformations. In the developing brain, KIF26A is preferentially expressed during early- and mid-gestation in excitatory neurons. Combining mice and human iPSC-derived organoid models, we discovered that loss of KIF26A causes excitatory neuron-specific defects in radial migration, localization, dendritic and axonal growth, and apoptosis, offering a convincing explanation of the disease etiology in patients. Single-cell RNA sequencing in KIF26A knockout organoids revealed transcriptional changes in MAPK, MYC, and E2F pathways. Our findings illustrate the pathogenesis of KIF26A loss-of-function variants and identify the surprising versatility of this non-motor kinesin.


Asunto(s)
Cinesinas , Neuronas , Humanos , Animales , Ratones , Cinesinas/genética , Neuronas/metabolismo , Proteína-Tirosina Quinasas de Adhesión Focal/metabolismo , Apoptosis , Encéfalo/metabolismo
9.
Ecol Evol ; 12(10): e9427, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36267683

RESUMEN

Maternal effects have the potential to alter early developmental processes of offspring and contribute to adaptive diversification. Egg size is a major contributor to offspring phenotype, which can influence developmental trajectories and potential resource use. However, to what extent intraspecific variation in egg size facilitates evolution of resource polymorphism is poorly understood. We studied multiple resource morphs of Icelandic Arctic charr, ranging from an anadromous morph-with a phenotype similar to the proposed ancestral phenotype-to sympatric morphs that vary in their degree of phenotypic divergence from the ancestral anadromous morph. We characterized variation in egg size and tested whether egg size influenced offspring phenotype at early life stages (i.e., timing of- and size at- hatching and first feeding [FF]). We predicted that egg size would differ among morphs and be less variable as morphs diverge away from the ancestral anadromous phenotype. We also predicted that egg size would correlate with offspring size and developmental timing. We found morphs had different egg size, developmental timing, and size at hatching and FF. Egg size increased as phenotypic proximity to the ancestral anadromous phenotype decreased, with larger eggs generally giving rise to larger offspring, especially at FF, but egg size had no effect on developmental rate. The interaction between egg size and the environment may have a profound impact on offspring fitness, where the resulting differences in early life-history traits may act to initiate and/or maintain resource morphs diversification.

10.
Sci Adv ; 8(35): eabm5800, 2022 09 02.
Artículo en Inglés | MEDLINE | ID: mdl-36044564

RESUMEN

The color patterns that adorn animals' coats not only exhibit extensive diversity linked to various ecological functions but also display recurrences in geometry, orientation, or body location. How processes of pattern formation shape such phenotypic trends remains a mystery. Here, we surveyed plumage color patterns in passerine finches displaying extreme apparent variation and identified a conserved set of color domains. We linked these domains to putative embryonic skin regions instructed by early developmental tissues and outlined by the combinatory expression of few genetic markers. We found that this embryonic prepattern is largely conserved in birds displaying drastic color differences in the adult, interspecies variation resulting from the masking or display of each domain depending on their coloration. This work showed that a simple molecular landscape serves as common spatial template to extensive color pattern variation in finches, revealing that early conserved landmarks and molecular pathways are a major cause of phenotypic trends.


Asunto(s)
Pinzones , Animales , Color , Pinzones/genética
11.
Acad Emerg Med ; 29(8): 928-943, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35426962

RESUMEN

OBJECTIVES: Medications for opioid use disorder (MOUD) prescribed in the emergency department (ED) have the potential to save lives and help people start and maintain recovery. We sought to explore patient perspectives regarding the initiation of buprenorphine and methadone in the ED with the goal of improving interactions and fostering shared decision making (SDM) around these important treatment options. METHODS: We conducted semistructured interviews with a purposeful sample of people with opioid use disorder (OUD) regarding ED visits and their experiences with MOUD. The interview guide was based on the Ottawa Decision Support Framework, a framework for examining decisional needs and tailoring decisional support, and the research team's experience with MOUD and SDM. Interviews were recorded, transcribed, and analyzed in an iterative process using both the Ottawa Framework and a social-ecological framework. Themes were identified and organized and implications for clinical care were noted and discussed. RESULTS: Twenty-six participants were interviewed, seven in person in the ED and 19 via video conferencing software. The majority had tried both buprenorphine and methadone, and almost all had been in an ED for an issue related to opioid use. Participants reported social, pharmacological, and emotional factors that played into their decision making. Regarding buprenorphine, they noted advantages such as its efficacy and logistical ease and disadvantages such as the need to wait to start it (risk of precipitated withdrawal) and that one could not use other opioids while taking it. Additionally, participants felt that: (1) both buprenorphine and methadone should be offered; (2) because "one person's pro is another person's con," clinicians will need to understand the facets of the options; (3) clinicians will need to have these conversations without appearing judgmental; and (4) many patients may not be "ready" for MOUD, but it should still be offered. CONCLUSIONS: Although participants were supportive of offering buprenorphine in the ED, many felt that methadone should also be offered. They felt that treatment should be tailored to an individual's needs and circumstances and clarified what factors might be important considerations for people with OUD.


Asunto(s)
Buprenorfina , Trastornos Relacionados con Opioides , Analgésicos Opioides/uso terapéutico , Buprenorfina/uso terapéutico , Servicio de Urgencia en Hospital , Humanos , Metadona/uso terapéutico , Tratamiento de Sustitución de Opiáceos/psicología , Trastornos Relacionados con Opioides/tratamiento farmacológico
12.
Ecol Evol ; 11(20): 14024-14032, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34707836

RESUMEN

Genetic variation in resistance against parasite infections is a predominant feature in host-parasite systems. However, mechanisms maintaining genetic polymorphism in resistance in natural host populations are generally poorly known. We explored whether differences in natural infection pressure between resource-based morphs of Arctic charr (Salvelinus alpinus) have resulted in differentiation in resistance profiles. We experimentally exposed offspring of two morphs from Lake Þingvallavatn (Iceland), the pelagic planktivorous charr ("murta") and the large benthivorous charr ("kuðungableikja"), to their common parasite, eye fluke Diplostomum baeri, infecting the eye humor. We found that there were no differences in resistance between the morphs, but clear differences among families within each morph. Moreover, we found suggestive evidence of resistance of offspring within families being positively correlated with the parasite load of the father, but not with that of the mother. Our results suggest that the inherited basis of parasite resistance in this system is likely to be related to variation among host individuals within each morph rather than ecological factors driving divergent resistance profiles at morph level. Overall, this may have implications for evolution of resistance through processes such as sexual selection.

13.
BMC Dev Biol ; 20(1): 21, 2020 10 26.
Artículo en Inglés | MEDLINE | ID: mdl-33106153

RESUMEN

BACKGROUND: Organismal fitness can be determined at early life-stages, but phenotypic variation at early life-stages is rarely considered in studies on evolutionary diversification. The trophic apparatus has been shown to contribute to sympatric resource-mediated divergence in several taxa. However, processes underlying diversification in trophic traits are poorly understood. Using phenotypically variable Icelandic Arctic charr (Salvelinus alpinus), we reared offspring from multiple families under standardized laboratory conditions and tested to what extent family (i.e. direct genetic and maternal effects) contributes to offspring morphology at hatching (H) and first feeding (FF). To understand the underlying mechanisms behind early life-stage variation in morphology, we examined how craniofacial shape varied according to family, offspring size, egg size and candidate gene expression. RESULTS: Craniofacial shape (i.e. the Meckel's cartilage and hyoid arch) was more variable between families than within families both across and within developmental stages. Differences in craniofacial morphology between developmental stages correlated with offspring size, whilst within developmental stages only shape at FF correlated with offspring size, as well as female mean egg size. Larger offspring and offspring from females with larger eggs consistently had a wider hyoid arch and contracted Meckel's cartilage in comparison to smaller offspring. CONCLUSIONS: This study provides evidence for family-level variation in early life-stage trophic morphology, indicating the potential for parental effects to facilitate resource polymorphism.


Asunto(s)
Estadios del Ciclo de Vida/fisiología , Cráneo/crecimiento & desarrollo , Trucha/crecimiento & desarrollo , Animales , Huesos Faciales/crecimiento & desarrollo , Conducta Alimentaria , Expresión Génica , Herencia Materna , Osteogénesis/genética , Fenotipo , Trucha/genética
14.
Evol Dev ; 21(1): 16-30, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30474913

RESUMEN

Gene expression during development shapes the phenotypes of individuals. Although embryonic gene expression can have lasting effects on developmental trajectories, few studies consider the role of maternal effects, such as egg size, on gene expression. Using qPCR, we characterize relative expression of 14 growth and/or skeletal promoting genes across embryonic development in Arctic charr (Salvelinus alpinus). We test to what extent their relative expression is correlated with egg size and size at early life-stages within the study population. We predict smaller individuals to have higher expression of growth and skeletal promoting genes, due to less maternal resources (i.e., yolk) and prioritization of energy toward ossification. We found expression levels to vary across developmental stages and only three genes (Mmp9, Star, and Sgk1) correlated with individual size at a given developmental stage. Contrary to our hypothesis, expression of Mmp9 and Star showed a non-linear relationship with size (at post fertilization and hatching, respectively), whilst Sgk1 was higher in larger embryos at hatching. Interestingly, these genes are also associated with craniofacial divergence of Arctic charr morphs. Our results indicate that early life-stage variation in gene expression, concomitant to maternal effects, can influence developmental plasticity and potentially the evolution of resource polymorphism in fishes.


Asunto(s)
Expresión Génica , Osteogénesis , Trucha/crecimiento & desarrollo , Trucha/genética , Animales , Tamaño Corporal , Femenino , Masculino , Herencia Materna , ARN Mensajero/análisis
15.
Science ; 361(6408)2018 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-30237324

RESUMEN

The periodic stripes and spots that often adorn animals' coats have been largely viewed as self-organizing patterns, forming through dynamics such as Turing's reaction-diffusion within the developing skin. Whether preexisting positional information also contributes to the periodicity and orientation of these patterns has, however, remained unclear. We used natural variation in colored stripes of juvenile galliform birds to show that stripes form in a two-step process. Autonomous signaling from the somite sets stripe position by forming a composite prepattern marked by the expression profile of agouti Subsequently, agouti regulates stripe width through dose-dependent control of local pigment production. These results reveal that early developmental landmarks can shape periodic patterns upstream of late local dynamics, and thus constrain their evolution.


Asunto(s)
Galliformes/embriología , Galliformes/fisiología , Pigmentación de la Piel , Somitos/fisiología , Proteína de Señalización Agouti/genética , Animales , Galliformes/clasificación , Galliformes/genética , Dosificación de Gen
16.
PLoS One ; 12(7): e0179557, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28742862

RESUMEN

The complex climatic and geological history of Southeast Asia has shaped this region's high biodiversity. In particular, sea level fluctuations associated with repeated glacial cycles during the Pleistocene both facilitated, and limited, connectivity between populations. In this study, we used data from two mitochondrial and three anonymous nuclear markers to determine whether a fresh/brackish water killifish, Aplocheilus panchax, Hamilton, 1822, could be used to further understand how climatic oscillations and associated sea level fluctuations have shaped the distribution of biota within this region, and whether such patterns show evidence of isolation within palaeodrainage basins. Our analyses revealed three major mitochondrial clades within A. panchax. The basal divergence of A. panchax mitochondrial lineages was approximately 3.5 Ma, whilst the subsequent divergence timings of these clades occurred early Pleistocene (~2.6 Ma), proceeding through the Pleistocene. Continuous phylogeographic analysis showed a clear west-east dispersal followed by rapid radiation across Southeast Asia. Individuals from Krabi, just north of the Isthmus of Kra, were more closely related to the Indian lineages, providing further evidence for a freshwater faunal disjunction at the Isthmus of Kra biogeographic barrier. Our results suggest that Sulawesi, across the Wallace Line, was colonised relatively recently (~30 ka). Nuclear DNA is less geographically structured, although Mantel tests indicated that nuclear genetic distances were correlated with geographic proximity. Overall, these results imply that recent gene flow, as opposed to historical isolation, has been the key factor determining patterns of nuclear genetic variation in A. panchax, however, some evidence of historical isolation is retained within the mitochondrial genome. Our study further validates the existence of a major biogeographic boundary at the Kra Isthmus, and also demonstrates the use of widely distributed fresh/brackishwater species in phylogeographic studies, and their ability to disperse across major marine barriers in relatively recent time periods.


Asunto(s)
Fundulidae/genética , Flujo Génico , Filogenia , Alelos , Animales , Asia Sudoriental , Biodiversidad , ADN Mitocondrial/genética , Evolución Molecular , Variación Genética , Genética de Población , Filogeografía , Análisis de Secuencia de ADN
17.
Chem Cent J ; 9: 11, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25798191

RESUMEN

BACKGROUND: Calculating Abraham descriptors from solubility values requires that the solute have the same form when dissolved in all solvents. However, carboxylic acids can form dimers when dissolved in non-polar solvents. For such compounds Abraham descriptors can be calculated for both the monomeric and dimeric forms by treating the polar and non-polar systems separately. We illustrate the method of how this can be done by calculating the Abraham descriptors for both the monomeric and dimeric forms of trans-cinnamic acid, the first time that descriptors for a carboxylic acid dimer have been obtained. RESULTS: Abraham descriptors were calculated for the monomeric form of trans-cinnamic acid using experimental solubility measurements in polar solvents from the Open Notebook Science Challenge together with a number of water-solvent partition coefficients from the literature. Similarly, experimental solubility measurements in non-polar solvents were used to determine Abraham descriptors for the trans-cinnamic acid dimer. CONCLUSION: Abraham descriptors were calculated for both the monomeric and dimeric forms of trans-cinnamic acid. This allows for the prediction of further solubilities of trans-cinnamic acid in both polar and non-polar solvents with an error of about 0.10 log units. Graphical abstractMolar concentration of trans-cinnamic acid in various polar and non-polar solvents.

18.
Cell ; 150(5): 922-33, 2012 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-22921915

RESUMEN

Propagation of gene-expression patterns through the cell cycle requires the existence of an epigenetic mark that re-establishes the chromatin architecture of the parental cell in the daughter cells. We devised assays to determine which potential epigenetic marks associate with epigenetic maintenance elements during DNA replication in Drosophila embryos. Histone H3 trimethylated at lysines 4 or 27 is present during transcription but, surprisingly, is replaced by nonmethylated H3 following DNA replication. Methylated H3 is detected on DNA only in nuclei not in S phase. In contrast, the TrxG and PcG proteins Trithorax and Enhancer-of-Zeste, which are H3K4 and H3K27 methylases, and Polycomb continuously associate with their response elements on the newly replicated DNA. We suggest that histone modification enzymes may re-establish the histone code on newly assembled unmethylated histones and thus may act as epigenetic marks.


Asunto(s)
Proteínas Cromosómicas no Histona/metabolismo , Replicación del ADN , Proteínas de Drosophila/metabolismo , Drosophila/metabolismo , Código de Histonas , Histonas/metabolismo , Animales , Drosophila/citología , Drosophila/genética , Embrión no Mamífero/metabolismo , Epigénesis Genética , Complejo Represivo Polycomb 1 , Antígeno Nuclear de Célula en Proliferación/metabolismo , Procesamiento Proteico-Postraduccional , Fase S
19.
Nucleic Acid Ther ; 21(4): 231-40, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21787231

RESUMEN

Oligonucleotides containing CpG motifs (cytosine-phosphate-guanosine oligodeoxynucleotide [CpG ODN]) display strong immunostimulatory effects, and polycations have been previously reported as cellular delivery system. In the present study, we investigated the adjuvant properties of combinations of a CpG ODN with various polycations (poly-arginine, poly-lysine, poly-histidine, or chitosan) in an ovalbumin vaccination model. We showed that, when combined to CpG ODN, poly-arginine and poly-histidine, but not poly-lysine or chitosan, enhanced efficiently both the IgG antibody production and the number of splenocytes secreting interferon-gamma after stimulation with a CD8+ T cell-restricted peptide. Interestingly, CpG ODN-poly-arginine, which was the most efficient, compared favorably to the complete Freund's adjuvant and aluminium salts and induced no local toxicity, making this combination a very attractive adjuvant for vaccines.


Asunto(s)
Adyuvantes Inmunológicos/farmacología , Sueros Inmunes/metabolismo , Oligodesoxirribonucleótidos/farmacología , Ovalbúmina/inmunología , Poliaminas/farmacología , Vacunación/métodos , Compuestos de Alumbre/farmacología , Animales , Células Cultivadas , Quitosano/farmacología , Estabilidad de Medicamentos , Ensayo de Cambio de Movilidad Electroforética , Adyuvante de Freund/farmacología , Histidina/farmacología , Inmunidad Celular/efectos de los fármacos , Inmunidad Humoral/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Tamaño de la Partícula , Péptidos/farmacología , Polielectrolitos , Polilisina/farmacología
20.
Cancer Res ; 71(12): 4068-73, 2011 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-21498638

RESUMEN

Elucidating how cancer cells respond to antagonists of HER receptor family members is critical to understanding mechanisms of therapeutic resistance that arise in patients. In large part, resistance to such agents appears to arise from deregulation of the phosphatidylinositol-3-kinase (PI3K)/Akt/mTOR pathway. mTOR-dependent phosphorylation of the translation repressor 4E-BP1 leads to its dissociation from eIF4E, thereby causing an increase in the formation of the eIF4F complex, which also comprises eIF4G and eIF4A. In this study, we show that trastuzumab, cetuximab, and erlotinib all decrease the formation of the eIF4F complex in breast, colon, and head and neck cancer cells, respectively. Ectopic expression of eIF4E restores the trastuzumab-dependent defect in eIF4F formation, renders cells resistant to the trastuzumab-mediated decrease in cell proliferation, and rescues breast cancer xenografts from inhibition by trastuzumab. In breast tumor specimens, the level of eIF4E expression is associated with the therapeutic response to a trastuzumab-based regimen. Together, our findings suggest that formation of the eIF4F complex may be a critical determinant of the response to anticancer drugs that target HER2 and epidermal growth factor receptor.


Asunto(s)
Antineoplásicos/farmacología , Receptores ErbB/antagonistas & inhibidores , Factor 4F Eucariótico de Iniciación/metabolismo , Receptor ErbB-2/antagonistas & inhibidores , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Anticuerpos Monoclonales/farmacología , Anticuerpos Monoclonales Humanizados , Neoplasias de la Mama/tratamiento farmacológico , Proteínas de Ciclo Celular , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Cetuximab , Resistencia a Antineoplásicos , Femenino , Humanos , Fosfoproteínas/metabolismo , Fosforilación , Trastuzumab
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