444,582 research outputs found
A Requirement for Fatty Acid Oxidation in the Hormone-Induced Meiotic Maturation of Mouse Oocytes
We have previously shown that fatty acid oxidation (FAO) is required for AMP-activated protein kinase (PRKA)-induced maturation in vitro. In the present study, we have further investigated the role of this metabolic pathway in hormone-induced meiotic maturation. Incorporating an assay with 3H-palmitic acid as the substrate, we first examined the effect of PRKA activators on FAO levels. There was a significant stimulation of FAO in cumulus cell-enclosed oocytes (CEO) treated with 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) and RSVA405. In denuded oocytes (DO), AICAR stimulated FAO only in the presence of carnitine, the molecule that facilitates fatty acyl CoA entry into the mitochondria. The carnitine palmitoyltransferase 1 activator C75 successfully stimulated FAO in CEO. All three of these activators trigger germinal vesicle breakdown. Meiotic resumption induced by follicle-stimulating hormone (FSH) or amphiregulin was completely inhibited by the FAO inhibitors etomoxir, mercaptoacetate, and malonyl CoA. Importantly, FAO was increased in CEO stimulated by FSH and epidermal growth factor, and this increase was blocked by FAO inhibitors. Moreover, compound C, a PRKA inhibitor, prevented the FSH-induced increase in FAO. Both carnitine and palmitic acid augmented hormonal induction of maturation. In a more physiological setting, etomoxir eliminated human chorionic gonadotropin (hCG)-induced maturation in follicle-enclosed oocytes. In addition, CEO and DO from hCG-treated mice displayed an etomoxir-sensitive increase in FAO, indicating that this pathway was stimulated during in vivo meiotic resumption. Taken together, our data indicate that hormone-induced maturation in mice requires a PRKA-dependent increase in FAO
Fatty Acid Oxidation and Meiotic Resumption in Mouse Oocytes
We have examined the potential role of fatty acid oxidation (FAO) in AMP-activated protein kinase (AMPK)-induced meiotic maturation. Etomoxir and malonyl CoA, two inhibitors of carnitine palmitoyl transferase-1 (CPT1), and thus FAO, blocked meiotic induction in dbcAMP-arrested cumulus cell-enclosed oocytes (CEO) and denuded oocytes (DO) by the AMPK activator, AICAR. C75, an activator of CPT1 and FAO, stimulated meiotic resumption in CEO and DO. This effect was insensitive to the AMPK inhibitor, compound C, indicating an action downstream of AMPK. Palmitic acid or carnitine also promoted meiotic resumption in DO in the presence of AICAR. Since C75 also suppresses the activity of fatty acid synthase (FAS), we tested another FAS inhibitor, cerulenin. Cerulenin stimulated maturation in arrested oocytes, but to a lesser extent, exhibited significantly slower kinetics and was effective in CEO but not DO. Moreover, etomoxir completely blocked C75-induced maturation but was ineffective in cerulenin-treated oocytes, suggesting that the meiosis-inducing action of C75 is through activation of FAO within the oocyte, while that of cerulenin is independent of FAO and acts within the cumulus cells. Finally, we determined that long chain, but not short chain, fatty acyl carnitine derivatives were stimulatory to oocyte maturation. Palmitoyl carnitine stimulated maturation in both CEO and DO, with rapid kinetics in DO; this effect was blocked by mercaptoacetate, a downstream inhibitor of FAO. These results indicate that activation of AMPK stimulates meiotic resumption in mouse oocytes by eliminating a block to FAO
Fedora Commons 3.0 Versus DSpace 1.5 : Selecting an Enterprise-Grade Repository System for FAO of the United Nations
4th International Conference on Open RepositoriesThis presentation was part of the session : Conference PostersAn extensive evaluation of the Fedora Commons 3.0 and DSpace 1.5 digital document repository systems has been conducted. The evaluation aimed at selecting an open source software package that best satisfies the FAO Open Archive and FAO organizational requirements and the requirements for the storage, dissemination and preservation of documents and bibliographic metadata. Both repository systems were evaluated against thirty-two criteria chosen from nine core categories of requirements: community, security, functionality, integration, modularity, metadata, statistics and reports, preservation, and outputs. These criteria were selected with the merger of the FAODOC and FAO Corporate Document Repository (CDR) into the FAO Open Archive in mind.Food and Agriculture Organization of the United Nation
International Guidelines for Securing Sustainable Small-scale Fisheries
The 'Zero Draft' of the International Guidelines for Securing Sustainable Small-scale Fisheries(SSF Guidelines) has been prepared based on the outcomes of the extensive consultation process that has taken place during the last few years. This preliminary draft text draws in particular on the Discussion Document: Towards Voluntary Guidelines on Securing Sustainable Small-scale Fisheriesâprepared as a stock-taking exercise by the FAO SSF Guidelines Secretariat in July 2011 and the contributions to and the outcomes of the FAO Workshop on International Guidelines for Securing Sustainable Small-scale Fisheries held on 7-10 February 2012 in FAO, Rome. It has been prepared to stimulate further consultations among all concerned parties. The outcomes of these additional consultations will provide guidance to the FAO Secretariat when preparing the text of the SSF Guidelines that will be submitted as a draft to the formal inter-governmental negotiation process tentatively scheduled for May 2013
ASFA: Back from the Edge and Moving towards a New Horizon
Since its establishment in 1971, ASFA has steadily grown its partnerships and database, paying increasing attention to developing countriesâ needs. However, its technologies and partnership model have failed to keep pace with modern developments. In order to address this, the FAO ASFA Secretariat has decided to implement a new Business Model by 2023, and will work with its stakeholders, including the Impact and Strategies Working Group and Strategic Advisory Group, to ensure ASFA remains a valued information product. The new business model will ensure ASFA meets FAO strategic objectives and wider goals of increasing access and dissemination of aquatic sciences and fisheries information. Several analyses have been performed by the ASFA Secretariat and others, which have informed ASFAâs direction. Work has already progressed on a number of areas that will be discussed in this presentation, specifically: ASFA technologies (new input software; online controlled vocabulary); ASFA collaborations (partnering with FAO departments and projects as well as external collaborations); and ASFA partnership model (a new Publishing Agreement with increased access for institutions in developing countries). However, a number of areas of work are to be determined, one of them being the MOU between FAO and IAMSLIC. Updating the MOU could lead to better collaboration between IAMSLIC and ASFA, in line with FAO goals, especially in the area of digital preservation
Inhibition of fatty acid oxidation as a therapy for MYC-overexpressing triple-negative breast cancer.
Expression of the oncogenic transcription factor MYC is disproportionately elevated in triple-negative breast cancer (TNBC), as compared to estrogen receptor-, progesterone receptor- or human epidermal growth factor 2 receptor-positive (RP) breast cancer. We and others have shown that MYC alters metabolism during tumorigenesis. However, the role of MYC in TNBC metabolism remains mostly unexplored. We hypothesized that MYC-dependent metabolic dysregulation is essential for the growth of MYC-overexpressing TNBC cells and may identify new therapeutic targets for this clinically challenging subset of breast cancer. Using a targeted metabolomics approach, we identified fatty acid oxidation (FAO) intermediates as being dramatically upregulated in a MYC-driven model of TNBC. We also identified a lipid metabolism gene signature in patients with TNBC that were identified from The Cancer Genome Atlas database and from multiple other clinical data sets, implicating FAO as a dysregulated pathway that is critical for TNBC cell metabolism. We found that pharmacologic inhibition of FAO catastrophically decreased energy metabolism in MYC-overexpressing TNBC cells and blocked tumor growth in a MYC-driven transgenic TNBC model and in a MYC-overexpressing TNBC patient-derived xenograft. These findings demonstrate that MYC-overexpressing TNBC shows an increased bioenergetic reliance on FAO and identify the inhibition of FAO as a potential therapeutic strategy for this subset of breast cancer
Exercise-Induced Changes in Exhaled NO Differentiates Asthma With or Without Fixed Airway Obstruction From COPD With Dynamic Hyperinflation.
Asthmatic patients with fixed airway obstruction (FAO) and patients with chronic obstructive pulmonary disease (COPD) share similarities in terms of irreversible pulmonary function impairment. Exhaled nitric oxide (eNO) has been documented as a marker of airway inflammation in asthma, but not in COPD. To examine whether the basal eNO level and the change after exercise may differentiate asthmatics with FAO from COPD, 27 normal subjects, 60 stable asthmatics, and 62 stable COPD patients were studied. Asthmatics with FAO (nâ=â29) were defined as showing a postbronchodilator FEV(1)/forced vital capacity (FVC) â€70% and FEV(1) less than 80% predicted after inhaled salbutamol (400âÎŒg). COPD with dynamic hyperinflation (nâ=â31) was defined as a decrease in inspiratory capacity (ÎIC%) after a 6 minute walk test (6MWT). Basal levels of eNO were significantly higher in asthmatics and COPD patients compared to normal subjects. The changes in eNO after 6MWT were negatively correlated with the percent change in IC (râ=ââ0.380, nâ=â29, Pâ=â0.042) in asthmatics with FAO. Their levels of basal eNO correlated with the maximum mid-expiratory flow (MMEF % predicted) before and after 6MWT. In COPD patients with air-trapping, the percent change of eNO was positively correlated to ÎIC% (rsâ=â0.404, nâ=â31, Pâ=â0.024). We conclude that asthma with FAO may represent residual inflammation in the airways, while dynamic hyperinflation in COPD may retain NO in the distal airspace. eNO changes after 6MWT may differentiate the subgroups of asthma or COPD patients and will help toward delivery of individualized therapy for airflow obstruction
Combining interactive GIS tools and expert knowledge in validation of tree species models
Poster presented at XIII Congreso Forestal Mundial. FAO, Buenos Aires (Argentina). 18-25 Oct 200
Framework for a pro-poor regional strategy on sustainable aquatic resources management in Asia-Pacific: a statement of understanding and recommendations
This statement was prepared by the participants of the FAO/NACA-STREAM Workshop on Aquatic Resources and Livelihoods: Connecting Policy and People, 17-19 March 2005, in Los Baños, Laguna, Philippines. This was the concluding event of the FAO Technical Cooperation
Program (TCP) project entitled âAssistance in Poverty Alleviation through Improved Aquatic Resources Management in Asia-Pacific.â The purpose of the workshop was to review and share experiences of the NACA-STREAM Initiative, build consensus on the value of livelihoods
approaches in aquatic resources management and poverty alleviation, and identify ways of promoting livelihoods approaches throughout the region. (Pdf contains 2 pages)
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