962 research outputs found

    Modelling aspects of oviduct fluid formation in vitro

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    © 2017 Society for Reproduction and Fertility. Oviduct fluid is the microenvironment that supports early reproductive processes including fertilisation, embryo cleavage and genome activation. However, the composition and regulation of this critical environment remain rather poorly defined. This study uses an in vitro preparation of the bovine oviduct epithelium to investigate the formation and composition of in vitro-derived oviduct fluid (ivDOF) within a controlled environment. We confirm the presence of oviduct-specific glycoprotein 1 in ivDOF and show that the amino acid and carbohydrate content resembles that of previously reported in vivo data. In parallel, using a different culture system, a panel of oviduct epithelial solute carrier genes and the corresponding flux of amino acids within ivDOF in response to steroid hormones were investigated. We next incorporated fibroblasts directly beneath the epithelium. This dual culture arrangement represents more faithfully the in vivo environment and impacts on ivDOF composition. Lastly, physiological and pathophysiological endocrine states were modelled and their impact on the in vitro oviduct preparation was evaluated. These experiments help clarify the dynamic function of the oviduct in vitro and suggest a number of future research avenues, such as investigating epithelial-fibroblast interactions, probing the molecular aetiologies of subfertility and optimising embryo culture media

    Proteomic analysis of Daphnia magna hints at molecular pathways involved in defensive plastic responses

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    Background: Phenotypic plasticity in defensive traits occurs in many species when facing heterogeneous predator regimes. The waterflea Daphnia is well-known for showing a variety of these so called inducible defences. However, molecular mechanisms underlying this plasticity are poorly understood so far. We performed proteomic analysis on Daphniamagna exposed to chemical cues of the predator Triops cancriformis. D. magna develops an array of morphological changes in the presence of Triops including changes of carapace morphology and cuticle hardening. Results: Using the 2D-DIGE technique, 1500 protein spots could be matched and quantified. We discovered 179 protein spots with altered intensity when comparing Triops exposed animals to a control group, and 69 spots were identified using nano-LC MS/MS. Kairomone exposure increased the intensity of spots containing muscle proteins, cuticle proteins and chitin-modifying enzymes as well as enzymes of carbohydrate and energy metabolism. The yolk precursor protein vitellogenin decreased in abundance in 41 of 43 spots. Conclusion: Identified proteins may be either directly involved in carapace stability or reflect changes in energy demand and allocation costs in animals exposed to predator kairomones. Our results present promising candidate proteins involved in the expression of inducible defences in Daphnia and enable further in depth analysis of this phenomenon

    LC-MS/MS-based proteome profiling in Daphnia pulex and Daphnia longicephala: the Daphnia pulex genome database as a key for high throughput proteomics in Daphnia

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    <p>Abstract</p> <p>Background</p> <p>Daphniids, commonly known as waterfleas, serve as important model systems for ecology, evolution and the environmental sciences. The sequencing and annotation of the <it>Daphnia pulex </it>genome both open future avenues of research on this model organism. As proteomics is not only essential to our understanding of cell function, and is also a powerful validation tool for predicted genes in genome annotation projects, a first proteomic dataset is presented in this article.</p> <p>Results</p> <p>A comprehensive set of 701,274 peptide tandem-mass-spectra, derived from <it>Daphnia pulex</it>, was generated, which lead to the identification of 531 proteins. To measure the impact of the <it>Daphnia pulex </it>filtered models database for mass spectrometry based <it>Daphnia </it>protein identification, this result was compared with results obtained with the Swiss-Prot and the <it>Drosophila melanogaster </it>database. To further validate the utility of the <it>Daphnia pulex </it>database for research on other <it>Daphnia </it>species, additional 407,778 peptide tandem-mass-spectra, obtained from <it>Daphnia longicephala</it>, were generated and evaluated, leading to the identification of 317 proteins.</p> <p>Conclusion</p> <p>Peptides identified in our approach provide the first experimental evidence for the translation of a broad variety of predicted coding regions within the <it>Daphnia </it>genome. Furthermore it could be demonstrated that identification of <it>Daphnia longicephala </it>proteins using the <it>Daphnia pulex </it>protein database is feasible but shows a slightly reduced identification rate. Data provided in this article clearly demonstrates that the <it>Daphnia </it>genome database is the key for mass spectrometry based high throughput proteomics in <it>Daphnia</it>.</p

    Mitochondrial Dysregulation Secondary to Endoplasmic Reticulum Stress in Autosomal Dominant Tubulointerstitial Kidney Disease - UMOD (ADTKD-UMOD)

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    'Autosomal dominant tubulointerstitial kidney disease - UMOD' (ADTKD-UMOD) is caused by impaired maturation and secretion of mutant uromodulin (UMOD) in thick ascending limb of Henle loop (TAL) cells, resulting in endoplasmic reticulum (ER) stress and unfolded protein response (UPR). To gain insight into pathophysiology, we analysed proteome profiles of TAL-enriched outer renal medulla samples from ADTKD-UMOD and control mice by quantitative LC-MS/MS. In total, 212 differentially abundant proteins were identified. Numerous ER proteins, including BiP (HSPA5), phosphorylated eIF2 alpha (EIF2S1), ATF4, ATF6 and CHOP (DDIT3), were increased abundant, consistent with UPR. The abundance of hypoxia-inducible proteins with stress survival functions, i.e. HYOU1, TXNDC5 and ERO1L, was also increased. TAL cells in ADTKD-UMOD showed a decreased proportion of mitochondria and reduced abundance of multiple mitochondrial proteins, associated with disturbed post-translational processing and activation of the mitochondrial transcription factor NRF1. Impaired fission of organelles, as suggested by reduced abundance of FIS1, may be another reason for disturbed biogenesis of mitochondria and peroxisomes. Reduced amounts of numerous proteins of the OXPHOS and citrate cycle pathways, and activation of the LKB1-AMPK-pathway, a sensor pathway of cellular energy deficits, suggest impaired energy homeostasis. In conclusion, our study revealed secondary mitochondrial dysfunction in ADTKD-UMOD

    Quantum-enabled operation of a microwave-optical interface

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    Solid-state microwave systems offer strong interactions for fast quantum logic and sensing but photons at telecom wavelength are the ideal choice for high-density low-loss quantum interconnects. A general-purpose interface that can make use of single photon effects requires < 1 input noise quanta, which has remained elusive due to either low efficiency or pump induced heating. Here we demonstrate coherent electro-optic modulation on nanosecond-timescales with only 0.16+0.02−0.01 microwave input noise photons with a total bidirectional transduction efficiency of 8.7% (or up to 15% with 0.41+0.02−0.02), as required for near-term heralded quantum network protocols. The use of short and high-power optical pump pulses also enables near-unity cooperativity of the electro-optic interaction leading to an internal pure conversion efficiency of up to 99.5%. Together with the low mode occupancy this provides evidence for electro-optic laser cooling and vacuum amplification as predicted a decade ago

    Policy instruments and welfare state reform

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    A core, but so far untested, proposition of the new politics perspective, originally introduced by Paul Pierson, is that welfare state cutbacks will be implemented using so-called ‘invisible’ policy instruments, for example, a change in indexation rules. Expansion should, by implication, mainly happen using ‘visible’ policy instruments, for example, a change in nominal benefits. We have coded 1030 legislative reforms of old-age pensions and unemployment protection in Britain, Denmark, Finland and Germany from 1974 to 2014. With this unique data at hand, we find substantial support for this crucial new politics proposition

    Insights into replicative senescence of human testicular peritubular cells

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    There is evidence for an age-related decline in male reproductive functions, yet how the human testis may age is not understood. Human testicular peritubular cells (HTPCs) transport sperm, contribute to the spermatogonial stem cell (SSC) niche and immune surveillance, and can be isolated and studied in vitro. Consequences of replicative senescence of HTPCs were evaluated to gain partial insights into human testicular aging. To this end, early and advanced HTPC passages, in which replicative senescence was indicated by increased cell size, altered nuclear morphology, enhanced beta-galactosidase activity, telomere attrition and reduced mitochondrial DNA (mtDNA), were compared. These alterations are typical for senescent cells, in general. To examine HTPC-specific changes, focused ion beam scanning electron microscopy (FIB/SEM) tomography was employed, which revealed a reduced mitochondrial network and an increased lysosome population. The results coincide with the data of a parallel proteomic analysis and indicate deranged proteostasis. The mRNA levels of typical contractility markers and growth factors, important for the SSC niche, were not significantly altered. A secretome analysis identified, however, elevated levels of macrophage migration inhibitory factor (MIF) and dipeptidyl peptidase 4 (DPP4), which may play a role in spermatogenesis. Testicular DPP4 may further represent a possible drug target

    A proteomic analysis of an in vitro knock-out of miR-200c

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    Loss of miR-200c is correlated to advanced cancer-subtypes due to increased EMT and decreased treatment efficacy by chemotherapeutics. As miRNAs regulate a multitude of targets, the analysis of differentially expressed proteins upon a genomic knock-out (KO) is of interest. In this study, we generated a TALENs KO of miR-200c in MCF7 breast cancer cells, excluded its compensation by family-members and evaluated the impact on the proteome by analyzing three individual KO-clones. We identified 26 key proteins and a variety of enrichments in metabolic and cytoskeletal pathways. In six of these targets (AGR2, FLNA/B, ALDH7A1, SCIN, GSTM3) the differential expression was additionally detected at mRNA level. Together, these alterations in protein abundance accounted for the observed biological phenotypes, i.e. increased migration and chemoresistance and altered metabolism, found in the miR-200c-KO clones. These findings provide novel insights into miR-200c and pave the way for further studies

    Geographical Requirements for the Applicability of the Results of the RACECAT Study to Other Stroke Networks.

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    Background The RACECAT (Transfer to the Closest Local Stroke Center vs Direct Transfer to Endovascular Stroke Center of Acute Stroke Patients With Suspected Large Vessel Occlusion in the Catalan Territory) trial was the first randomized trial addressing the prehospital triage of acute stroke patients based on the distribution of thrombolysis centers and intervention centers in Catalonia, Spain. The study compared the drip-and-ship with the mothership paradigm in regions where a local thrombolysis center can be reached faster than the nearest intervention center (equipoise region). The present study aims to determine the population-based applicability of the results of the RACECAT study to 4 stroke networks with a different degree of clustering of the intervention centers (clustered, dispersed). Methods and Results Stroke networks were compared with regard to transport time saved for thrombolysis (under the drip-and-ship approach) and transport time saved for endovascular therapy (under the mothership approach). Population-based transport times were modeled with a local instance of an openrouteservice server using open data from OpenStreetMap.The fraction of the population in the equipoise region differed substantially between clustered networks (Catalonia, 63.4%; France North, 87.7%) and dispersed networks (Southwest Bavaria, 40.1%; Switzerland, 40.0%). Transport time savings for thrombolysis under the drip-and-ship approach were more marked in clustered networks (Catalonia, 29 minutes; France North, 27 minutes) than in dispersed networks (Southwest Bavaria and Switzerland, both 18 minutes). Conclusions Infrastructure differences between stroke networks may hamper the applicability of the results of the RACECAT study to other stroke networks with a different distribution of intervention centers. Stroke networks should assess the population densities and hospital type/distribution in the temporal domain before applying prehospital triage algorithms to their specific setting

    Metabolic implication of tigecycline as an efficacious second-line treatment for sorafenib-resistant hepatocellular carcinoma

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    Sorafenib represents the current standard of care for patients with advanced-stage hepatocellular carcinoma (HCC). However, acquired drug resistance occurs frequently during therapy and is accompanied by rapid tumor regrowth after sorafenib therapy termination. To identify the mechanism of this therapy-limiting growth resumption, we established robust sorafenib resistance HCC cell models that exhibited mitochondrial dysfunction and chemotherapeutic crossresistance. We found a rapid relapse of tumor cell proliferation after sorafenib withdrawal, which was caused by renewal of mitochondrial structures alongside a metabolic switch toward high electron transport system (ETS) activity. The translation-inhibiting antibiotic tigecycline impaired the biogenesis of mitochondrial DNA-encoded ETS subunits and limited the electron acceptor turnover required for glutamine oxidation. Thereby, tigecycline prevented the tumor relapse in vitro and in murine xenografts in vivo. These results offer a promising second-line therapeutic approach for advanced-stage HCC patients with progressive disease undergoing sorafenib therapy or treatment interruption due to severe adverse events
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