Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.104
Filtrar
1.
J Dairy Sci ; 107(3): 1523-1534, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37690722

RESUMEN

Feed efficiency has become an increasingly important research topic in recent years. As feed costs rise and the environmental impacts of agriculture become more apparent, improving the efficiency with which dairy cows convert feed to milk is increasingly important. However, feed intake is expensive to measure accurately on large populations, making the inclusion of this trait in breeding programs difficult. Understanding how the genetic parameters of feed efficiency and traits related to feed efficiency vary throughout the lactation period is valuable to gain understanding into the genetic nature of feed efficiency. This study used 121,226 dry matter intake (DMI) records, 120,500 energy-corrected milk (ECM) records, and 98,975 metabolic body weight (MBW) records, collected on 7,440 first-lactation Holstein cows from 6 countries (Canada, Denmark, Germany, Spain, Switzerland, and the United States), from January 2003 to February 2022. Genetic parameters were estimated using a multiple-trait random regression model with a fourth-order Legendre polynomial for all traits. Weekly phenotypes for DMI were re-parameterized using linear regressions of DMI on ECM and MBW, creating a measure of feed efficiency that was genetically corrected for ECM and MBW, referred to as genomic residual feed intake (gRFI). Heritability (SE) estimates varied from 0.15 (0.03) to 0.29 (0.02) for DMI, 0.24 (0.01) to 0.29 (0.03) for ECM, 0.55 (0.03) to 0.83 (0.05) for MBW, and 0.12 (0.03) to 0.22 (0.06) for gRFI. In general, heritability estimates were lower in the first stage of lactation compared with the later stages of lactation. Additive genetic correlations between weeks of lactation varied, with stronger correlations between weeks of lactation that were close together. The results of this study contribute to a better understanding of the change in genetic parameters across the first lactation, providing insight into potential selection strategies to include feed efficiency in breeding programs.


Asunto(s)
Lactancia , Leche , Animales , Femenino , Bovinos/genética , Lactancia/genética , Ingestión de Alimentos/genética , Agricultura , Fenotipo
2.
IEEE Trans Pattern Anal Mach Intell ; 45(2): 2519-2532, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35503820

RESUMEN

Event cameras are an exciting, new sensor modality enabling high-speed imaging with extremely low-latency and wide dynamic range. Unfortunately, most machine learning architectures are not designed to directly handle sparse data, like that generated from event cameras. Many state-of-the-art algorithms for event cameras rely on interpolated event representations-obscuring crucial timing information, increasing the data volume, and limiting overall network performance. This paper details an event representation called Time-Ordered Recent Event (TORE) volumes. TORE volumes are designed to compactly store raw spike timing information with minimal information loss. This bio-inspired design is memory efficient, computationally fast, avoids time-blocking (i.e., fixed and predefined frame rates), and contains "local memory" from past data. The design is evaluated on a wide range of challenging tasks (e.g., event denoising, image reconstruction, classification, and human pose estimation) and is shown to dramatically improve state-of-the-art performance. TORE volumes are an easy-to-implement replacement for any algorithm currently utilizing event representations.

3.
J Dairy Sci ; 105(7): 5954-5971, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35636997

RESUMEN

Residual feed intake (RFI) and feed saved (FS) are important feed efficiency traits that have been increasingly considered in genetic improvement programs. Future sustainability of these genetic evaluations will depend upon greater flexibility to accommodate sparsely recorded dry matter intake (DMI) records on many more cows, especially from commercial environments. Recent multiple-trait random regression (MTRR) modeling developments have facilitated days in milk (DIM)-specific inferences on RFI and FS, particularly in modeling the effect of change in metabolic body weight (MBW). The MTRR analyses, using daily data on the core traits of DMI, MBW, and milk energy (MilkE), were conducted separately for 2,532 primiparous and 2,379 multiparous US Holstein cows from 50 to 200 DIM. Estimated MTRR variance components were used to derive genetic RFI and FS and DIM-specific genetic partial regressions of DMI on MBW, MilkE, and change in MBW. Estimated daily heritabilities of RFI and FS varied across lactation for both primiparous (0.05-0.07 and 0.11-0.17, respectively) and multiparous (0.03-0.13 and 0.10-0.17, respectively) cows. Genetic correlations of RFI across DIM varied (>0.05) widely compared with FS (>0.54) within either parity class. Heritability estimates based on average lactation-wise measures were substantially larger than daily heritabilities, ranging from 0.17 to 0.25 for RFI and from 0.35 to 0.41 for FS. The partial genetic regression coefficients of DMI on MBW (0.11 to 0.16 kg/kg0.75 for primiparous and 0.12 to 0.14 kg/kg0.75 for multiparous cows) and of DMI on MilkE (0.45 to 0.68 kg/Mcal for primiparous and 0.36 to 0.61 kg/Mcal for multiparous cows) also varied across lactation. In spite of the computational challenges encountered with MTRR, the model potentially facilitates an efficient strategy for harnessing more data involving a wide variety of data recording scenarios for genetic evaluations on feed efficiency.


Asunto(s)
Lactancia , Leche , Alimentación Animal/análisis , Animales , Peso Corporal/genética , Bovinos/genética , Ingestión de Alimentos/genética , Femenino , Lactancia/genética , Leche/metabolismo , Fenotipo , Embarazo
4.
Clin Pharmacokinet ; 60(1): 121-131, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32856281

RESUMEN

BACKGROUND AND OBJECTIVE: Ampreloxetine is a novel norepinephrine reuptake inhibitor in development for the treatment of symptomatic neurogenic orthostatic hypotension. The objectives of this analysis were to define the pharmacokinetics of once-daily oral ampreloxetine and provide dose recommendations for clinical development. METHODS: We fitted a population pharmacokinetic model to ampreloxetine plasma concentrations from single- and multiple-ascending dose trials in healthy subjects and two phase II studies in adult subjects with attention-deficit/hyperactive disorder or fibromyalgia at doses of 2-50 mg. RESULTS: Ampreloxetine pharmacokinetics was best described by a two-compartment model with first-order absorption and elimination. The terminal half-life was 30-40 h, resulting in sustained drug concentrations for the entire 24-h dosing interval at steady state. Covariates of age, weight, or renal impairment did not impact ampreloxetine exposure. Cytochrome P450 2D6 phenotype had no influence on ampreloxetine exposure. Sex and smoking status were identified as statistically significant covariates, suggesting a role for cytochrome P450 1A2 in the elimination of ampreloxetine. Despite statistical significance, differences in ampreloxetine exposure in male vs female subjects and smokers vs non-smokers were not clinically meaningful at the recommended dose. At the 10-mg dose, > 75% norepinephrine transporter inhibition and < 50% serotonin transporter inhibition are anticipated for adult subjects. CONCLUSIONS: The population pharmacokinetic model effectively described the plasma concentration-time profile of ampreloxetine after single and multiple doses. Population pharmacokinetic/pharmacodynamic analysis justified using a fixed dosing regimen with no dose adjustments across a broad population and can be used to inform dosing strategies in future clinical studies. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifier numbers NCT01693692 (fibromyalgia); NCT01458340 (attention-deficit/hyperactive disorder).


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad , Fibromialgia , Éteres Fenílicos , Piperidinas , Adulto , Trastorno por Déficit de Atención con Hiperactividad/tratamiento farmacológico , Trastorno por Déficit de Atención con Hiperactividad/metabolismo , Estudios de Casos y Controles , Femenino , Fibromialgia/tratamiento farmacológico , Fibromialgia/metabolismo , Humanos , Masculino , Norepinefrina , Dolor/tratamiento farmacológico , Dolor/metabolismo , Éteres Fenílicos/administración & dosificación , Éteres Fenílicos/farmacocinética , Piperidinas/administración & dosificación , Piperidinas/farmacocinética
5.
Clin Transl Sci ; 13(6): 1307-1315, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32506827

RESUMEN

TD-0714 is an orally active, potent, and selective inhibitor of human neprilysin (NEP) in development for the treatment of chronic heart failure. Oral administration of TD-0714 in rats resulted in dose-dependent and sustained increases in plasma cyclic guanosine monophosphate (cGMP) over 24 hours consistent with NEP target engagement. Randomized, double-blind, placebo controlled, single ascending dose (50-600 mg TD-0714) and multiple ascending dose (10-200 mg TD-0714 q.d. for 14 days) studies were conducted in healthy volunteers. TD-0714 was generally well-tolerated and no serious adverse events or clinically significant effects on vital signs or electrocardiogram parameters were observed. TD-0714 exhibited dose-proportional pharmacokinetics (PKs) with high oral bioavailability, minimal accumulation after once daily dosing, and negligible renal elimination. Pharmacodynamic (PD) responses were observed at all dose levels studied, as reflected by statistically significant increases in plasma cGMP concentrations. The increases in cGMP were significantly above the baseline (~ 50-100%) on day 14 for the entire 24-hour interval indicating that sustained cGMP elevations are achieved at steady-state. Maximal steady-state cGMP response was observed in plasma and urine at doses ≥ 50 mg. The TD-0714 PK-PD relationship and safety profile were similar in elderly vs. younger adult subjects. The TD-0714 PK and PD profiles support further clinical development of TD-0714 and suggest the potential for once-daily administration and predictable exposure in patients with cardiorenal diseases regardless of their renal function.


Asunto(s)
Cardiotónicos/administración & dosificación , Neprilisina/antagonistas & inhibidores , Administración Oral , Adulto , Anciano , Animales , Área Bajo la Curva , Disponibilidad Biológica , Cardiotónicos/efectos adversos , Enfermedad Crónica/tratamiento farmacológico , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Evaluación Preclínica de Medicamentos , Femenino , Semivida , Voluntarios Sanos , Insuficiencia Cardíaca/tratamiento farmacológico , Humanos , Masculino , Persona de Mediana Edad , Ratas , Eliminación Renal , Adulto Joven
6.
J Dairy Sci ; 102(4): 3097-3109, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30772021

RESUMEN

The aim of this research was to study the effect of milking frequency [once-daily milking (ODM) vs. twice-daily milking (TDM)] and antioxidant (AOX) supplementation on fatty acid (FA) profile and oxidative stability in sheep milk. Sixteen Assaf ewes were used; 8 did not receive any vitamin-mineral supplement (control), and the other 8 received an oral dose of 1,000 IU of α-tocopherol and 0.4 mg of Se daily. The experiment consisted of 2 consecutive periods; the first was 3 wk with TDM of both mammary glands. The second period was 8 wk and consisted of ODM of one mammary gland and TDM of the other gland. All ewes were fed ad libitum the same total mixed ration from lambing and throughout the experiment. There were no differences in plasma or milk Se concentrations between control and AOX ewes. However, plasma and milk α-tocopherol concentrations and AOX capacity were increased in ewes receiving the AOX supplement. Milk FA profile was practically unaffected after 21 d of AOX supplementation. However, after 77 d, AOX supplementation increased the relative percentage of C16:0 and cis-9 C18:1 and reduced the proportions of some saturated FA with less than 16 carbons and cis-9 C12:1. Antioxidant supplementation had no effect on the proportions of conjugated linoleic acid or total polyunsaturated FA (PUFA) but decreased the proportion of trans-7,cis-9 C18:2 and increased that of n-6 C20:3. Once-daily milking did not affect α-tocopherol, Se, or fat resistance to oxidation in milk. Total monounsaturated FA, cis-9 C16:1, and several cis and trans isomers of C18:1 were increased and total saturated FA were decreased in milk from ODM glands. Compared with TDM, ODM increased the proportions of cis-9,cis-12 C18:2 and several isomers of C18:2 and reduced those of cis-9,cis-12,cis-15 C18:3 and some PUFA of 20 and 22 carbons, but total proportion of PUFA was unaffected. Once-daily milking and AOX supplementation modified milk FA profile, but the effects of ODM could be considered of little biological relevance for consumer health. Supplementing ewes with α-tocopherol plus Se could be considered an effective strategy to improve plasma AOX status and reduce milk fat oxidation without substantial changes in the milk FA profile.


Asunto(s)
Ácidos Grasos/química , Leche/metabolismo , Selenio/metabolismo , Ovinos/metabolismo , alfa-Tocoferol/metabolismo , Alimentación Animal/análisis , Animales , Dieta/veterinaria , Suplementos Dietéticos/análisis , Ácidos Grasos/metabolismo , Femenino , Ácidos Linoleicos Conjugados/metabolismo , Leche/química , Oxidación-Reducción
7.
Mol Biol Cell ; 30(6): 778-793, 2019 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-30699057

RESUMEN

Protein arginine methyltransferases (PRMTs) are a family of enzymes that modify proteins by methylating the guanidino nitrogen atoms of arginine residues to regulate cellular processes such as chromatin remodeling, pre-mRNA splicing, and signal transduction. PRMT7 is the single type III PRMT solely capable of arginine monomethylation. To date, other than histone proteins, there are very few identified substrates of PRMT7. We therefore performed quantitative mass spectrometry experiments to identify PRMT7's interactome and potential substrates to better characterize the enzyme's biological function(s) in cells. These experiments revealed that PRMT7 interacts with and can methylate eukaryotic translation initiation factor 2 alpha (eIF2α), in vitro and in breast cancer cells. Furthermore, we uncovered a potential regulatory interplay between eIF2α arginine methylation by PRMT7 and stress-induced phosphorylation status of eIF2α at serine 51. Finally, we demonstrated that PRMT7 is required for eIF2α-dependent stress granule formation in the face of various cellular stresses. Altogether, our findings implicate PRMT7 as a novel mediator of eIF2α-dependent cellular stress response pathways.


Asunto(s)
Factor 2 Eucariótico de Iniciación/metabolismo , Proteína-Arginina N-Metiltransferasas/fisiología , Secuencia de Aminoácidos , Arginina/metabolismo , Línea Celular , Citosol/fisiología , Metilación de ADN , Factor 2 Eucariótico de Iniciación/fisiología , Factores Eucarióticos de Iniciación/metabolismo , Células HEK293 , Histonas/metabolismo , Humanos , Células MCF-7 , Metilación , Fosforilación , Procesamiento Proteico-Postraduccional , Proteína-Arginina N-Metiltransferasas/metabolismo , Estrés Fisiológico/fisiología
8.
Mol Phylogenet Evol ; 122: 1-14, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29294405

RESUMEN

Phylogeography can provide insight into the potential for speciation and identify geographic regions and evolutionary processes associated with species richness and evolutionary endemism. In the marine environment, highly mobile species sometimes show structured patterns of diversity, but the processes isolating populations and promoting differentiation are often unclear. The Delphinidae (oceanic dolphins) are a striking case in point and, in particular, bottlenose dolphins (Tursiops spp.). Understanding the radiation of species in this genus is likely to provide broader inference about the processes that determine patterns of biogeography and speciation, because both fine-scale structure over a range of kilometers and relative panmixia over an oceanic range are known for Tursiops populations. In our study, novel Tursiops spp. sequences from the northwest Indian Ocean (including mitogenomes and two nuDNA loci) are included in a worldwide Tursiops spp. phylogeographic analysis. We discover a new 'aduncus' type lineage in the Arabian Sea (off India, Pakistan and Oman) that diverged from the Australasian lineage ∼261 Ka. Effective management of coastal dolphins in the region will need to consider this new lineage as an evolutionarily significant unit. We propose that the establishment of this lineage could have been in response to climate change during the Pleistocene and show data supporting hypotheses for multiple divergence events, including vicariance across the Indo-Pacific barrier and in the northwest Indian Ocean. These data provide valuable transferable inference on the potential mechanisms for population and species differentiation across this geographic range.


Asunto(s)
Delfín Mular/clasificación , Animales , Delfín Mular/genética , ADN Mitocondrial/química , ADN Mitocondrial/clasificación , ADN Mitocondrial/genética , Sitios Genéticos , Variación Genética , Océano Índico , Filogenia , Filogeografía , Análisis de Secuencia de ADN
9.
Pharmacogenomics J ; 18(1): 35-42, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-27845419

RESUMEN

Neutropenia is a common dose-limiting toxicity associated with irinotecan treatment. Although UGT1A1 variants have been associated with neutropenia, a fraction of neutropenia risk remains unaccounted for. To identify additional genetic markers contributing to variability in irinotecan pharmacokinetics and neutropenia, a regression analysis was performed in 78 irinotecan-treated patients to analyze comprehensively three hepatic efflux transporter genes (ABCB1, ABCC1 and ABCG2). rs6498588 (ABCC1) and rs12720066 (ABCB1) were associated with increased SN-38 exposure, and rs17501331 (ABCC1) and rs12720066 were associated with lower absolute neutrophil count nadir. rs6498588 and a variant in high linkage disequilibrium are located in transcriptionally active regions or are predicted to alter transcription factor binding sites. While enhancer activity was not evident in vitro for genomic regions containing these single-nucleotide polymorphisms, rs6498588 was significantly associated with ABCC1 expression in human liver. These results suggest that genetic variation in ABCC1 and ABCB1 may contribute to irinotecan-induced neutropenia by altering expression of transporters involved in irinotecan metabolite disposition.


Asunto(s)
Transportadoras de Casetes de Unión a ATP/genética , Irinotecán/farmacocinética , Neutropenia/genética , Neutropenia/metabolismo , Polimorfismo de Nucleótido Simple/genética , Adulto , Anciano , Femenino , Genotipo , Humanos , Masculino , Proteínas de Transporte de Membrana/genética , Persona de Mediana Edad , Proteínas de Neoplasias/genética , Activación Transcripcional/genética
10.
Dev Cell ; 43(6): 716-730.e7, 2017 12 18.
Artículo en Inglés | MEDLINE | ID: mdl-29257951

RESUMEN

Autophagy and autophagy-related genes (Atg) have been attributed prominent roles in tumorigenesis, tumor growth, and metastasis. Extracellular vesicles called exosomes are also implicated in cancer metastasis. Here, we demonstrate that exosome production is strongly reduced in cells lacking Atg5 and Atg16L1, but this is independent of Atg7 and canonical autophagy. Atg5 specifically decreases acidification of late endosomes where exosomes are produced, disrupting the acidifying V1V0-ATPase by removing a regulatory component, ATP6V1E1, into exosomes. The effect of Atg5 on exosome production promotes the migration and in vivo metastasis of orthotopic breast cancer cells. These findings uncover mechanisms controlling exosome release and identify means by which autophagy-related genes can contribute to metastasis in autophagy-independent pathways.


Asunto(s)
Proteína 5 Relacionada con la Autofagia/metabolismo , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , ATPasas de Translocación de Protón Vacuolares/metabolismo , Animales , Autofagia/fisiología , Proteína 5 Relacionada con la Autofagia/genética , Proteína 7 Relacionada con la Autofagia/genética , Proteína 7 Relacionada con la Autofagia/metabolismo , Línea Celular Tumoral/metabolismo , Endosomas/metabolismo , Exosomas/metabolismo , Femenino , Humanos , Lisosomas/metabolismo , Ratones , Ratones Endogámicos BALB C , Metástasis de la Neoplasia , ATPasas de Translocación de Protón Vacuolares/genética
11.
Sci Rep ; 7(1): 5153, 2017 07 11.
Artículo en Inglés | MEDLINE | ID: mdl-28698590

RESUMEN

Tudor domain containing protein 3 (TDRD3) is a modular protein identified based on its ability to recognize methylated arginine motifs through its Tudor domain. We have previously shown that TDRD3 localizes to cytoplasmic stress granules, a structure shown to promote survival upon treatment with chemotherapeutic drugs in cancer cells. Here, we report TDRD3 as a novel regulator of cell proliferation and invasion in breast cancer cells. Our study also demonstrates that TDRD3 depletion inhibits tumor formation and metastasis to the lung in vivo. Furthermore, we show that TDRD3 regulates the expression of a number of key genes associated with promotion of breast cancer tumorigenesis and disease progression. Strikingly, we report that TDRD3 regulates some of these key targets at the level of translation. These findings provide the first experimental demonstration of a functional role for TDRD3 in promoting breast cancer development and progression, and identify TDRD3 as a potential new therapeutic target for breast cancer.


Asunto(s)
Neoplasias de la Mama/patología , Neoplasias Pulmonares/secundario , Proteínas/genética , Proteínas/metabolismo , Regulación hacia Arriba , Animales , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Células MCF-7 , Ratones , Invasividad Neoplásica , Trasplante de Neoplasias , Biosíntesis de Proteínas
12.
Int J Biochem Cell Biol ; 91(Pt B): 124-135, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28733251

RESUMEN

Aberrant expression of Protein Arginine Methyltransferases (PRMTs) has been observed in several cancer types, including breast cancer. We previously reported that the PRMT1v2 isoform, which is generated through inclusion of alternative exon 2, is overexpressed in breast cancer cells and promotes their invasiveness. However, the precise mechanism by which expression of this isoform is controlled and how it is dysregulated in breast cancer remains unknown. Using a custom RNA interference-based screen, we identified several RNA binding proteins (RBP) which, when knocked down, altered the relative abundance of the alternatively spliced PRMT1v2 isoform. Amongst the top hits were SNW Domain containing 1 (SNW1) and RBP-associated with lethal yellow mutation (RALY), which both associated with the PRMT1 pre-mRNA and upon depletion caused an increase or decrease in the relative abundance of PRMT1v2 isoform mRNA and protein. Most importantly, a significant decrease in invasion was observed upon RALY knockdown in aggressive breast cancer cells, consistent with targeting PRMT1v2 directly, and this effect was rescued by the exogenous re-expression of PRMT1v2. We show that SNW1 expression is decreased, while RALY expression is increased in breast cancer cells and tumours, which correlates with decreased patient survival. This work revealed crucial insight into the mechanisms regulating the expression of the PRMT1 alternatively spliced isoform v2 and its dysregulation in breast cancer. It also provides proof-of-concept support for the development of therapeutic strategies where regulators of PRMT1 exon 2 alternative splicing are targeted as an approach to selectively reduce PRMT1v2 levels and metastasis in breast cancer.


Asunto(s)
Empalme Alternativo , Neoplasias de la Mama/patología , Regulación Neoplásica de la Expresión Génica , Ribonucleoproteína Heterogénea-Nuclear Grupo C/metabolismo , Proteína-Arginina N-Metiltransferasas/genética , Proteína-Arginina N-Metiltransferasas/metabolismo , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Exones/genética , Humanos , Células MCF-7 , Metástasis de la Neoplasia , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Regulación hacia Arriba
13.
J Dairy Sci ; 100(4): 3004-3018, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28131587

RESUMEN

Glucagon-like peptide 2 (GLP-2) therapy was shown previously to reduce inflammation-related gut damage from coccidiosis in dairy calves, and feeding of artificial sweetener stimulates GLP-2 secretion from intestinal L cells. The purpose of this study was to determine whether GLP-2 treatment or artificial sweetener feeding beginning 1 wk before an experimental inoculation with the coccidian parasite Cryptosporidium parvum can reduce infection-related intestinal damage in Holstein bull calves. Newborn calves were assigned to 1 of 4 treatment groups of 6 calves each, including noninfected control calves injected s.c. every 12 h with control buffer (CON), infected control calves injected s.c. every 12 h with control buffer (INF), infected calves injected s.c. every 12 h with 50 µg/kg of body weight of GLP-2 (GLP2), and infected calves injected s.c. every 12 h with control buffer and supplemented in the diet with Sucram (Pancosma, Geneva, Switzerland) at 400 mg/kg of dry matter of milk replacer (SUC). Treatments were initiated on d 1, and calves in INF, GLP2, and SUC were orally dosed on d 8 with 12,500 C. parvum oocysts. Fecal scores were recorded daily, plasma was collected on d 1, 8, 12, 15, and 18 to evaluate markers of inflammation, and fecal samples were collected on d 1, 8, and every other day thereafter to determine the presence of oocysts. Calves were euthanized on d 18 for collection of intestinal tissues and histological and gene expression analyses. Relative to CON, calves in INF exhibited an increase in diarrhea severity, increased plasma serum amyloid A concentration on d 15 and 18, reduced intestinal villus height, increased villus apoptosis and crypt cell proliferation, and increased intestinal mRNA expression of MARVELD2 and GPX2. However, calves in SUC and GLP2 had reduced diarrhea severity and fecal C. parvum oocyst shedding, reduced plasma serum amyloid A concentration on d 15 and 18, and, depending on the intestinal segment, increased villus height, reduced crypt cell proliferation, and reduced mRNA expression of MARVELD2, GPX2, and other tight junction proteins relative to INF. Lastly, GLP2 and SUC exhibited increased intestinal mass-to-length ratio and decreased length-to-empty body weight ratio relative to INF. Our findings suggest that GLP-2 and Sucram treatments administered before a low-level C. parvum exposure may contribute to fewer effects on intestinal integrity, morphology, and inflammation in response to infection, and shorter, denser intestines.


Asunto(s)
Cryptosporidium parvum , Péptido 2 Similar al Glucagón , Animales , Bovinos , Enfermedades de los Bovinos/prevención & control , Criptosporidiosis , Masculino , Edulcorantes
14.
Domest Anim Endocrinol ; 56 Suppl: S56-65, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27345324

RESUMEN

Numerous endocrine cell subtypes exist within the intestinal mucosa and produce peptides contributing to the regulation of critical physiological processes including appetite, energy metabolism, gut function, and gut health. The mechanisms of action and the extent of the physiological effects of these enteric peptides are only beginning to be uncovered. One peptide in particular, glucagon-like peptide 2 (GLP-2) produced by enteroendocrine L cells, has been fairly well characterized in rodent and swine models in terms of its ability to improve nutrient absorption and healing of the gut after injury. In fact, a long-acting form of GLP-2 recently has been approved for the management and treatment of human conditions like inflammatory bowel disease and short bowel syndrome. However, novel functions of GLP-2 within the gut continue to be demonstrated, including its beneficial effects on intestinal barrier function and reducing intestinal inflammation. As knowledge continues to grow about GLP-2's effects on the gut and its mechanisms of release, the potential to use GLP-2 to improve gut function and health of food animals becomes increasingly more apparent. Thus, the purpose of this review is to summarize: (1) the current understanding of GLP-2's functions and mechanisms of action within the gut; (2) novel applications of GLP-2 (or stimulators of its release) to improve general health and production performance of food animals; and (3) recent findings, using dairy calves as a model, that suggest the therapeutic potential of GLP-2 to reduce the pathogenesis of intestinal protozoan infections.


Asunto(s)
Tracto Gastrointestinal/efectos de los fármacos , Péptido 2 Similar al Glucagón/farmacología , Péptido 2 Similar al Glucagón/fisiología , Ganado/fisiología , Animales , Bovinos , Enfermedades de los Bovinos/tratamiento farmacológico , Enfermedades de los Bovinos/parasitología , Tracto Gastrointestinal/fisiología , Humanos , Infecciones Protozoarias en Animales/tratamiento farmacológico
15.
J Anim Sci ; 93(5): 2382-90, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-26020334

RESUMEN

Butyrate, a major rumen VFA, has been indirectly linked to enhancement of urea recycling on the basis of increased expression of urea transporter in the rumen epithelia of steers fed a rumen butyrate-enhancing diet. Two studies were conducted to quantify the effect of elevated rumen butyrate concentrations on N balance, urea kinetics and rumen epithelial proliferation. Wether sheep (n= 4), fitted with a rumen cannula, were fed a pelleted ration (∼165 g CP/kg DM, 10.3 MJ ME/kg DM) at 1.8 × ME requirement. In Exp. 1, sheep were infused intraruminally with either an electrolyte buffer solution (Con-Buf) or butyrate dissolved in the buffer solution (But-Buf) during 8-d periods in a balanced crossover design. In Exp. 2, sheep were infused intraruminally with either sodium acetate (Na-Ac) or sodium butyrate (Na-But) for 9 d. All solutions were adjusted to pH 6.8 and 8.0 in Exp. 1 and 2, respectively, and VFA were infused at 10% of ME intake. [15N2] urea was continuously infused intravenously for the last 5 d of each period, and total urine and feces were collected. In Exp. 1, 2H5-phenylalanine was continuously infused intravenously over the last 12 h, after which a biopsy from the rumen papillae was taken for measurement of fractional protein synthesis rate (FSR). Butyrate infusion treatments increased (P = 0.1 in Exp. 1; P < 0.05 in Exp. 2) the proportion of rumen butyrate, and acetate infusion increased (P < 0.05) rumen acetate. All animals were in positive N balance (4.2 g N/d in Exp. 1; 7.0 g N/d in Exp. 2), but no difference in N retention was observed between treatments. In Exp. 2, urea entry (synthesis) rate was reduced ( < 0.05) by Na-But compared with the Na-Ac control. In Exp. 1, although But-Buf infusion increased the FSR of rumen papillae (35.3% ± 1.08%/d vs. 28.7% ± 1.08%/d; P < 0.05), urea kinetics were not altered by But-Buf compared with Con-Buf. These studies are the first to directly assess the role of butyrate in urea recycling and its effects on rumen papillae protein turnover in growing lambs. Under the feeding conditions used and the rate of continuous butyrate infusion into the rumen in the present studies, butyrate does not affect overall N retention in growing sheep. However, butyrate may play a role in the redistribution of urea N fluxes in the overall scheme of N metabolism.


Asunto(s)
Alimentación Animal , Butiratos/metabolismo , Nitrógeno/metabolismo , Rumen/metabolismo , Ovinos/metabolismo , Urea/metabolismo , Alimentación Animal/análisis , Animales , Ácido Butírico/farmacología , Digestión/efectos de los fármacos , Digestión/fisiología , Ingestión de Alimentos/efectos de los fármacos , Ingestión de Alimentos/fisiología , Heces/química , Concentración de Iones de Hidrógeno , Masculino , Nitrógeno/análisis , Rumen/efectos de los fármacos , Acetato de Sodio/farmacología
16.
Proteomics ; 15(13): 2187-97, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25690678

RESUMEN

Arginine methylation is catalyzed by a family of enzymes called protein arginine methyltransferases (PRMTs). The PRMT1 gene generates at least seven distinct alternatively spliced isoforms (PRMT v1-v7), which together contribute a significant portion of the cellular arginine methylome. The distinct biochemical and biological functions of these PRMT1 isoforms have not been well characterized. Previously we have shown that while both PRMT1v1 and PRMT1v2 are overexpressed in breast cancer cells, PRMT1v2 specifically promotes breast cancer cell survival and invasion. These isoforms also have distinct subcellular localizations, PRMT1v1 is mainly nuclear and PRMT1v2 cytosolic. To gain further knowledge into their isoform-specific roles within cells we used a SILAC-based quantitative affinity purification/MS approach to identify their individual protein interactomes in breast cancer cells. This analysis has uncovered distinct interactomes for PRMT1v1 and PRMT1v2. Consistent with their distinct subcellular localizations, PRMT1v1 enriched a mainly nuclear protein interactome, while PRMT1v2 enriched predominantly cytoplasmic interactors from whole-cell extracts. Furthermore, these interactomes revealed that PRMT1v1 has a role in regulating gene expression, while PRMT1v2 functions in cytoskeletal dynamics. These results highlight the unique functions of these isoforms and the distinct roles they may play within cells, with potential implications for breast cancer and other diseases.


Asunto(s)
Neoplasias de la Mama/metabolismo , Proteína-Arginina N-Metiltransferasas/metabolismo , Proteínas Represoras/metabolismo , Línea Celular , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Humanos , Espectrometría de Masas , Microscopía Fluorescente , Proteína-Arginina N-Metiltransferasas/genética , Proteínas Represoras/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
17.
Mutagenesis ; 30(2): 177-89, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25688111

RESUMEN

Breast cancer is the most commonly diagnosed female cancer in the world. Though therapeutic treatments are available to treat breast cancer and in some instances are successful, the occurrence of unsuccessful treatment, or the rate of tumour recurrence, still remains strikingly high. Therefore, novel therapeutic treatment targets need to be discovered and tested. The protein arginine methyltransferases (PRMTs) are a family of enzymes that catalyse arginine methylation and are implicated in a myriad of cellular pathways including transcription, DNA repair, RNA metabolism, signal transduction, protein-protein interactions and subcellular localisation. In breast cancer, the expression levels and enzymatic activity of a number of PRMTs is dysregulated; significantly altering the regulation of many cellular pathways that are implicated in breast cancer development and progression. Here, we review the current knowledge on PRMTs in breast cancer and provide a rationale for how PRMTs may provide novel therapeutic targets for the treatment of breast cancer.


Asunto(s)
Antineoplásicos/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/enzimología , Proteína-Arginina N-Metiltransferasas/antagonistas & inhibidores , Femenino , Humanos , Proteína-Arginina N-Metiltransferasas/fisiología
18.
Oncotarget ; 6(5): 3013-32, 2015 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-25605249

RESUMEN

Recent evidence points to the protein arginine methyltransferase (PRMT) family of enzymes playing critical roles in cancer. PRMT7 has been identified in several gene expression studies to be associated with increased metastasis and decreased survival in breast cancer patients. However, this has not been extensively studied. Here we report that PRMT7 expression is significantly upregulated in both primary breast tumour tissues and in breast cancer lymph node metastases. We have demonstrated that reducing PRMT7 levels in invasive breast cancer cells using RNA interference significantly decreased cell invasion in vitro and metastasis in vivo. Conversely, overexpression of PRMT7 in non-aggressive MCF7 cells enhanced their invasiveness. Furthermore, we show that PRMT7 induces the expression of matrix metalloproteinase 9 (MMP9), a well-known mediator of breast cancer metastasis. Importantly, we significantly rescued invasion of aggressive breast cancer cells depleted of PRMT7 by the exogenous expression of MMP9. Our results demonstrate that upregulation of PRMT7 in breast cancer may have a significant role in promoting cell invasion through the regulation of MMP9. This identifies PRMT7 as a novel and potentially significant biomarker and therapeutic target for breast cancer.


Asunto(s)
Neoplasias de la Mama/enzimología , Movimiento Celular , Metaloproteinasa 9 de la Matriz/metabolismo , Proteína-Arginina N-Metiltransferasas/metabolismo , Animales , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Femenino , Regulación Enzimológica de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Células HEK293 , Humanos , Ganglios Linfáticos/enzimología , Ganglios Linfáticos/patología , Metástasis Linfática , Metaloproteinasa 9 de la Matriz/genética , Ratones Endogámicos NOD , Ratones SCID , Invasividad Neoplásica , Proteína-Arginina N-Metiltransferasas/genética , Interferencia de ARN , Transducción de Señal , Transfección , Regulación hacia Arriba
19.
J Fish Biol ; 85(5): 1665-81, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25271907

RESUMEN

The aims of this study were first, to test the hypothesis that metrics of fish growth and condition relate positively to parasite species richness (S(R)) in a salmonid host; second, to identify whether S(R) differs as a function of host origin; third, to identify whether acquisition of parasites through marine v. freshwater trophic interactions was related to growth and condition of juvenile salmonids. To evaluate these questions, species diversity of trophically transmitted parasites in juvenile coho salmon Oncorhynchus kisutch collected off the coast of the Oregon and Washington states, U.S.A. in June 2002 and 2004 were analysed. Fish infected with three or more parasite species scored highest in metrics of growth and condition. Fish originating from the Columbia River basin had lower S(R) than those from the Oregon coast, Washington coast and Puget Sound, WA. Parasites obtained through freshwater or marine trophic interactions were equally important in the relationship between S(R) and ocean growth and condition of juvenile O. kisutch salmon.


Asunto(s)
Oncorhynchus kisutch/crecimiento & desarrollo , Oncorhynchus kisutch/parasitología , Parásitos/aislamiento & purificación , Animales , Biodiversidad , Interacciones Huésped-Parásitos , Oregon , Washingtón
20.
Anim Genet ; 45 Suppl 1: 40-50, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24990294

RESUMEN

This report presents a study utilizing next-generation sequencing technology, combined with chromatin immunoprecipitation (ChIP-seq) technology to analyze histone modification induced by butyrate and to construct a high-definition map of the epigenomic landscape with normal histone H3 and H4 and their variants in bovine cells at the whole-genome scale. A total of 10 variants of histone H3 and H4 modifications were mapped at the whole-genome scale (acetyl-H3K18-ChIP-seq, trimethy-H3K9, histone H4 ChIP-seq, acetyl-H4K5 ChIP-seq, acetyl-H4K12 ChIP-seq, acetyl-H4K16 ChIP-seq, histone H3 ChIP-seq, acetyl H3H9 ChIP-seq, acetyl H3K27 ChIP-seq and tetra-acetyl H4 ChIP-seq). Integrated experiential data and an analysis of histone and histone modification at a single base resolution across the entire genome are presented. We analyzed the enriched binding regions in the proximal promoter (within 5 kb upstream or at the 5'-untranslated region from the transcriptional start site (TSS)), and the exon, intron and intergenic regions (defined by regions 25 kb upstream and 10 kb downstream from the TSS). A de novo search for the binding motif of the 10 ChIP-seq datasets discovered numerous motifs from each of the ChIP-seq datasets. These consensus sequences indicated that histone modification at different locations changes the histone H3 and H4 binding preferences. Nevertheless, a high degree of conservation in histone binding also was presented in these motifs. This first extensive epigenomic landscape mapping in bovine cells offers a new framework and a great resource for testing the role of epigenomes in cell function and transcriptomic regulation.


Asunto(s)
Butiratos/farmacología , Bovinos/genética , Epigenómica/métodos , Genoma/efectos de los fármacos , Genoma/genética , Histonas/metabolismo , Animales , Inmunoprecipitación de Cromatina/veterinaria , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Secuenciación de Nucleótidos de Alto Rendimiento/veterinaria , Histonas/efectos de los fármacos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...