Gene expression profiling reveals effects of Cimicifuga racemosa (L.) NUTT. (black cohosh) on the estrogen receptor positive human breast cancer cell line MCF-7

BACKGROUND: Extracts from the rhizome of Cimicifuga racemosa (black cohosh) are increasingly popular as herbal alternative to hormone replacement therapy (HRT) for the alleviation of postmenopausal disorders. However, the molecular mode of action and the active principles are presently not clear. Previously published data have been largely contradictory. We, therefore, investigated the effects of a lipophilic black cohosh rhizome extract and cycloartane-type triterpenoids on the estrogen receptor positive human breast cancer cell line MCF-7. RESULTS: Both extract and purified compounds clearly inhibited cellular proliferation. Gene expression profiling with the extract allowed us to identify 431 regulated genes with high significance. The extract induced expression pattern differed from those of 17beta-estradiol or the estrogen receptor antagonist tamoxifen. We observed a significant enrichment of genes in an anti-proliferative and apoptosis-sensitizing manner, as well as an increase of mRNAs coding for gene products involved in several stress response pathways. These functional groups were highly overrepresented among all regulated genes. Also several transcripts coding for oxidoreductases were induced, as for example the cytochrome P450 family members 1A1 and 1B1. In addition, some transcripts associated with antitumor but also tumor-promoting activity were regulated. Real-Time RT-PCR analysis of 13 selected genes was conducted after treatment with purified compounds - the cycloartane-type triterpene glycoside actein and triterpene aglycons - showing similar expression levels compared to the extract. CONCLUSION: No estrogenic but antiproliferative and proapoptotic gene expression was shown for black cohosh in MCF-7 cells at the transcriptional level. The effects may be results of the activation of different pathways. The cycloartane glycosides and - for the first time - their aglycons could be identified as an active principle in black cohosh

WISER Deliverable D3.3-2: The importance of invertebrate spatial and temporal variation for ecological status classification for European lakes

European lakes are affected by many human induced disturbances. In principle, ecological theories predict that the structure and functioning of benthic invertebrate assemblage (one of the Biological Quality Elements following the Water Framework Directive, WFD terminology) change in response to the level of disturbances, making this biological element suitable for assessing the status and management of lake ecosystems. In practice, to set up assessment systems based on invertebrates, we need to distiguish community changes that are related to human pressures from those that are inherent natural variability. This task is complicated by the fact that invertebrate communities inhabiting the littoral and the profundal zones of lakes are constrained by different factors and respond unevenly to distinct human disturbances. For example it is not clear yet how the invertebrates assemblages respond to watershed and shoreline alterations, nor the relative importance of spatial and temporal factors on assemblage dynamics and relative bioindicator values of taxa, the habitat constraints on species traits and other taxonomic and methodological limitations. The current lack of knowledge of basic features of invertebrate temporal and spatial variations is limiting the fulfillment of the EU-wide intercalibration of lake ecological quality assessment systems in Europe, and thus compromising the basis for setting the environmental objectives as required by the WFD. The aim of this deliverable is to provide a contribution towards the understanding of basic sources of spatial and temporal variation of lake invertebrate assemblages. The report is structured around selected case studies, manly involving the analysis of existing datasets collated within WISER. The case studies come from different European lake types in the Northern, Central, Alpine and Mediterranean regions. All chapters have an obvious applied objective and our aim is to provide to those dealing with WFD implementation at various levels useful information to consider when designing monitoring programs and / or invertebrate-based classification systems

Hydraulically-actuated compliant revolute joint for medical robotic systems based on multimaterial additive manufacturing

IEEE International Conference on Robotics and Automation (ICRA), Montréal, Canada, janvier 2019 Research team : AV

Role of the hyporheic heterotrophic biofilm on transformation and toxicity of pesticides

The role of heterotrophic biofilm of water–sediment interface in detoxification processes was tested in abiotic and biotic conditions under laboratory conditions. Three toxicants, a herbicide (Diuron), a fungicide (Dimethomorph) and an insecticide (Chlorpyrifos-ethyl) have been tested in water percolating into columns reproducing hyporheic sediment. The detoxification processes were tested by comparing the water quality after 18 days of percolation with and without heterotrophic biofilm. Tested concentrations were 30 mg.Lx1 of Diuron diluted in 0.1% dimethyl sulfoxide (DMSO), 2 mg.Lx1 of Dimethomorph and 0.1 mg.Lx1 of Chlorpyrifos-ethyl. To characterise the detoxification efficiency of the system, we performed genotoxicity bioassays in amphibian larvae and rotifers and measured the respiration and denitrification of sediments. Although the presence of biofilm increased the production of N-(3,4 dichlorophenyl)-N-(methyl)-urea, a metabolite of diuron, the toxicity did not decrease irrespective of the bioassay. In the presence of biofilm, Dimethomorph concentrations decreased compared with abiotic conditions, from 2 mg.Lx1 to 0.4 mg.Lx1 after 18 days of percolation. For both Dimethomorph and Chlorpyrifos-ethyl additions, assessment of detoxification level by the biofilm depended on the test used: detoxification effect was found with amphibian larvae bioassay and no detoxification was observed with the rotifer test. Heterotrophic biofilm exerts a major influence in the biochemical transformation of contaminants such as pesticides, suggesting that the interface between running water and sediment plays a role in self-purification of stream reaches

Drosophila KCNQ Channel Displays Evolutionarily Conserved Electrophysiology and Pharmacology with Mammalian KCNQ Channels

Of the five human KCNQ (Kv7) channels, KCNQ1 with auxiliary subunit KCNE1 mediates the native cardiac IKs current with mutations causing short and long QT cardiac arrhythmias. KCNQ4 mutations cause deafness. KCNQ2/3 channels form the native M-current controlling excitability of most neurons, with mutations causing benign neonatal febrile convulsions. Drosophila contains a single KCNQ (dKCNQ) that appears to serve alone the functions of all the duplicated mammalian neuronal and cardiac KCNQ channels sharing roughly 50–60% amino acid identity therefore offering a route to investigate these channels. Current information about the functional properties of dKCNQ is lacking therefore we have investigated these properties here. Using whole cell patch clamp electrophysiology we compare the biophysical and pharmacological properties of dKCNQ with the mammalian neuronal and cardiac KCNQ channels expressed in HEK cells. We show that Drosophila KCNQ (dKCNQ) is a slowly activating and slowly-deactivating K+ current open at sub-threshold potentials that has similar properties to neuronal KCNQ2/3 with some features of the cardiac KCNQ1/KCNE1 accompanied by conserved sensitivity to a number of clinically relevant KCNQ blockers (chromanol 293B, XE991, linopirdine) and opener (zinc pyrithione). We also investigate the molecular basis of the differential selectivity of KCNQ channels to the opener retigabine and show a single amino acid substitution (M217W) can confer sensitivity to dKCNQ. We show dKCNQ has similar electrophysiological and pharmacological properties as the mammalian KCNQ channels, allowing future study of physiological and pathological roles of KCNQ in Drosophila and whole organism screening for new modulators of KCNQ channelopathies

Functional and clinical studies reveal pathophysiological complexity of CLCN4-related neurodevelopmental condition

Missense and truncating variants in the X-chromosome-linked CLCN4 gene, resulting in reduced or complete loss-of-function (LOF) of the encoded chloride/proton exchanger ClC-4, were recently demonstrated to cause a neurocognitive phenotype in both males and females. Through international clinical matchmaking and interrogation of public variant databases we assembled a database of 90 rare CLCN4 missense variants in 90 families: 41 unique and 18 recurrent variants in 49 families. For 43 families, including 22 males and 33 females, we collated detailed clinical and segregation data. To confirm causality of variants and to obtain insight into disease mechanisms, we investigated the effect on electrophysiological properties of 59 of the variants in Xenopus oocytes using extended voltage and pH ranges. Detailed analyses revealed new pathophysiological mechanisms: 25% (15/59) of variants demonstrated LOF, characterized by a “shift” of the voltage-dependent activation to more positive voltages, and nine variants resulted in a toxic gain-of-function, associated with a disrupted gate allowing inward transport at negative voltages. Functional results were not always in line with in silico pathogenicity scores, highlighting the complexity of pathogenicity assessment for accurate genetic counselling. The complex neurocognitive and psychiatric manifestations of this condition, and hitherto under-recognized impacts on growth, gastrointestinal function, and motor control are discussed. Including published cases, we summarize features in 122 individuals from 67 families with CLCN4-related neurodevelopmental condition and suggest future research directions with the aim of improving the integrated care for individuals with this diagnosis

Simple large wood structures promote hydromorphological heterogeneity and benthic macroinvertebrate diversity in low-gradient rivers

This work has been carried out within the SMART Joint Doctorate Programme ‘Science for the MAnagement of Rivers and their Tidal systems’ funded by the Erasmus Mundus programme of the European Union

Discovery of a Novel Activator of KCNQ1-KCNE1 K+ Channel Complexes

KCNQ1 voltage-gated K+ channels (Kv7.1) associate with the family of five KCNE peptides to form complexes with diverse gating properties and pharmacological sensitivities. The varied gating properties of the different KCNQ1-KCNE complexes enables the same K+ channel to function in both excitable and non excitable tissues. Small molecule activators would be valuable tools for dissecting the gating mechanisms of KCNQ1-KCNE complexes; however, there are very few known activators of KCNQ1 channels and most are ineffective on the physiologically relevant KCNQ1-KCNE complexes. Here we show that a simple boronic acid, phenylboronic acid (PBA), activates KCNQ1/KCNE1 complexes co-expressed in Xenopus oocytes at millimolar concentrations. PBA shifts the voltage sensitivity of KCNQ1 channel complexes to favor the open state at negative potentials. Analysis of different-sized charge carriers revealed that PBA also targets the permeation pathway of KCNQ1 channels. Activation by the boronic acid moiety has some specificity for the Kv7 family members (KCNQ1, KCNQ2/3, and KCNQ4) since PBA does not activate Shaker or hERG channels. Furthermore, the commercial availability of numerous PBA derivatives provides a large class of compounds to investigate the gating mechanisms of KCNQ1-KCNE complexes

The Arabidopsis thaliana F-Box Protein FBL17 Is Essential for Progression through the Second Mitosis during Pollen Development

In fungi and metazoans, the SCF-type Ubiquitin protein ligases (E3s) play a critical role in cell cycle regulation by degrading negative regulators, such as cell cycle-dependent kinase inhibitors (CKIs) at the G1-to-S-phase checkpoint. Here we report that FBL17, an Arabidopsis thaliana F-box protein, is involved in cell cycle regulation during male gametogenesis. FBL17 expression is strongly enhanced in plants co-expressing E2Fa and DPa, transcription factors that promote S-phase entry. FBL17 loss-of-function mutants fail to undergo pollen mitosis II, which generates the two sperm cells in mature A. thaliana pollen. Nonetheless, the single sperm cell-like cell in fbl17 mutants is functional but will exclusively fertilize the egg cell of the female gametophyte, giving rise to an embryo that will later abort, most likely due to the lack of functional endosperm. Seed abortion can, however, be overcome by mutations in FIE, a component of the Polycomb group complex, overall resembling loss-of-function mutations in the A. thaliana cyclin-dependent kinase CDKA;1. Finally we identified ASK11, as an SKP1-like partner protein of FBL17 and discuss a possible mechanism how SCFFBL17 may regulate cell division during male gametogenesis