68 research outputs found
Exploration of steam explosion treatment for the recovery of phenolic compounds
peer reviewe
Hypoxia promotes breast cancer cell invasion through HIF-1a-mediated up-regulation of the invadopodial actin bundling protein CSRP2
Hypoxia is a common feature of solid tumours that promotes invasion and metastatic dissemination. Invadopodia are actin-rich membrane protrusions that direct extracellular matrix proteolysis and facilitate tumour cell invasion. Here, we show that CSRP2, an invadopodial actin bundling protein, is upregulated by hypoxia in various breast cancer cell lines, as well as in pre-clinical and clinical breast tumour specimens. We functionally characterized two hypoxia responsive elements within the proximal promoter of CSRP2 gene which are targeted by hypoxia-inducible factor-1 (HIF-1) and required for promoter transactivation in response to hypoxia. Remarkably, CSRP2 knockdown significantly inhibits hypoxia-stimulated invadopodium formation, ECM degradation and invasion in MDA-MB-231 cells, while CSRP2 forced expression was sufficient to enhance the invasive capacity of HIF-1a-depleted cells under hypoxia. In MCF-7 cells, CSRP2 upregulation was required for hypoxia-induced formation of invadopodium precursors that were unable to promote ECM degradation. Collectively, our data support that CSRP2 is a novel and direct cytoskeletal target of HIF-1 which facilitates hypoxia-induced breast cancer cell invasion by promoting invadopodia formation.The authors are grateful to Monika Dieterle, Arnaud Muller, Pter Nazarov and Muhammad Zaeem Noman (Oncology Department, LIH, Luxembourg) for technical assistance, support in statistical analyses and constructive discussions. The authors also warmly thank Sara A. Courtneidge for the gift of the Tks5-GFP construct (Oregon Health and Science University, Portland, USA). This work was mainly supported by a research grant from “Fondation Cancer” Luxembourg (FC/2016/02), and the National Research Fund (C16/ BM/11297905). Joshua Brown Clay is recipient of a Postdoctoral fellowship from “Fonds De La Recherche Scientifque” - FNRS “Télévie” (7.4512.16). Antoun Al Absi and Hannah Wurzer are recipients of PhD fellowships from the National Research Fund, Luxembourg (AFR7892325 and PRIDE15/10675146/CANBIO, respectively)
Oncological care organisation during COVID-19 outbreak
Funding: This work was supported by Fonds de la Recherche Scientifique (grant to CEO) and Fondation Léon Fredericq (grant to GJ and CEO).Background: COVID-19 appeared in late 2019, causing a pandemic spread. This led to a reorganisation of oncology care in order to reduce the risk of spreading infection between patients and healthcare staff. Here we analysed measures taken in major oncological units in Europe and the USA. Methods: A 46-item survey was sent by email to representatives of 30 oncological centres in 12 of the most affected countries. The survey inquired about preventive measures established to reduce virus spread, patient education and processes employed for risk reduction in each oncological unit. Results: Investigators from 21 centres in 10 countries answered the survey between 10 April and 6 May 2020. A triage for patients with cancer before hospital or clinic visits was conducted by 90.5% of centres before consultations, 95.2% before day care admissions and in 100% of the cases before overnight hospitalisation by means of phone calls, interactive online platforms, swab test and/or chest CT scan. Permission for caregivers to attend clinic visits was limited in many centres, with some exceptions (ie, for non-autonomous patients, in the case of a new diagnosis, when bad news was expected and for terminally ill patients). With a variable delay period, the use of personal protective equipment was unanimously mandatory, and in many centres, only targeted clinical and instrumental examinations were performed. Telemedicine was implemented in 76.2% of the centres. Separated pathways for COVID-19-positive and COVID-19-negative patients were organised, with separate inpatient units and day care areas. Self-isolation was required for COVID-19-positive or symptomatic staff, while return to work policies required a negative swab test in 76.2% of the centres. Conclusion: Many pragmatic measures have been quickly implemented to deal with the health emergency linked to COVID-19, although the relative efficacy of each intervention should be further analysed in large observational studies
The human epidermal growth factor receptor (EGFR) gene in European patients with advanced colorectal cancer harbors infrequent mutations in its tyrosine kinase domain
ABSTRACT: BACKGROUND: The epidermal growth factor receptor (EGFR), a member of the ErbB family of receptors, is a transmembrane tyrosine kinase (TK) activated by the binding of extracellular ligands of the EGF-family and involved in triggering the MAPK signaling pathway, which leads to cell proliferation. Mutations in the EGFR tyrosine kinase domain are frequent in non-small-cell lung cancer (NSCLC). However, to date, only very few, mainly non-European, studies have reported rare EGFR mutations in colorectal cancer (CRC). METHODS: We screened 236 clinical tumor samples from European patients with advanced CRC by direct DNA sequencing to detect potential, as yet unknown mutations, in the EGFR gene exons 18 to 21, mainly covering the EGFR TK catalytic domain. RESULTS: EGFR sequences showed somatic missense mutations in exons 18 and 20 at a frequency of 2.1% and 0.4% respectively. Somatic SNPs were also found in exons 20 and 21 at a frequency of about 3.1% and 0.4% respectively. Of these mutations, four have not yet been described elsewhere. CONCLUSIONS: These mutation frequencies are higher than in a similarly sized population characterized by Barber and colleagues, but still too low to account for a major role played by the EGFR gene in CRC.Peer reviewe
Wind anisotropies and GRB progenitors
We study the effect of wind anisotropies on the stellar evolution leading to
collapsars. Rotating models of a 60 M star with on the ZAMS, accounting for shellular rotation and a magnetic
field, with and without wind anisotropies, are computed at =0.002 until the
end of the core He-burning phase. Only the models accounting for the effects of
the wind anisotropies retain enough angular momentum in their core to produce a
Gamma Ray Burst (GRB). The chemical composition is such that a type Ic
supernova event occurs. Wind anisotropies appear to be a key physical
ingredient in the scenario leading to long GRBs.Comment: 5 pages, 4 figures, accepted for publication in A&A Lette
Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)
In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field
Age at onset as stratifier in idiopathic Parkinson’s disease – effect of ageing and polygenic risk score on clinical phenotypes
Several phenotypic differences observed in Parkinson’s disease (PD) patients have been linked to age at onset (AAO). We endeavoured to find out whether these differences are due to the ageing process itself by using a combined dataset of idiopathic PD (n = 430) and healthy controls (HC; n = 556) excluding carriers of known PD-linked genetic mutations in both groups. We found several significant effects of AAO on motor and non-motor symptoms in PD, but when comparing the effects of age on these symptoms with HC (using age at assessment, AAA), only positive associations of AAA with burden of motor symptoms and cognitive impairment were significantly different between PD vs HC. Furthermore, we explored a potential effect of polygenic risk score (PRS) on clinical phenotype and identified a significant inverse correlation of AAO and PRS in PD. No significant association between PRS and severity of clinical symptoms was found. We conclude that the observed non-motor phenotypic differences in PD based on AAO are largely driven by the ageing process itself and not by a specific profile of neurodegeneration linked to AAO in the idiopathic PD patients
Etude du potentiel des sous produits de la filière vinicole pour des applications à haute valeur ajoutée
La raréfaction future des ressources fossiles est, à l’heure actuelle, une certitude. Face à la demande croissante d’une population mondiale en expansion constante, il est primordial de trouver des voies de production plus durables pour les produits de consommation courante.
La chimie biobasée et le bioraffinage constituent une alternative à laquelle il convient de porter une grande attention. La très grande quantité de biomasse constituée par les déchets verts produits à l’échelle planétaire représente une ressource énergétique et chimique très peu exploitée jusqu’à présent.
Les sous-produits vinicoles sont issus de l’une des cultures des plus répandues dans le monde et semblent constituer une source intéressante de molécules biobasées. Malgré ce potentiel, ces résidus ne sont que très peu valorisés à l’heure actuelle. Leur utilisation est presque exclusivement cantonnée à des applications de faibles valeurs ajoutées tels que le compostage, l’épandage sur champ ou la production de bioéthanol.
Ce travail est centré sur les possibilités de valorisation à haute valeur ajoutée des sous-produits vinicoles. Il s’inscrit dans la tendance actuelle d’utilisation de molécules bioactives d’origine végétale, tant dans le cadre d’applications pharmaceutiques que parapharmaceutiques ou agroalimentaires.
Cette étude est articulée autour de deux objectifs principaux : une caractérisation générale de la matière première et la mise au point d’une méthode d’extraction des polyphénols.
Les résultats de cette étude tendent à montrer le haut potentiel de valorisation des marcs de raisins grâce à l’identification de composés d’intérêt tels que des polyphénols ainsi qu’une concentration appréciable en plusieurs autres molécules d’intérêt dont le potentiel de valorisation au départ des sous-produits vinicoles reste à explorer.Nowadays, there is no longer any doubt about the future fossil fuels rarefaction. It is necessary to find more sustainable ways to produce everyday consumer products faced to an increasing population.
Bio-based chemistry and bio-refining are alternative solutions deserving a particular attention. The large amount of green waste produced all around the world represents energy and chemical resources with an under-exploited potential.
Wine-making byproducts come from grape growing which is one of the largest crop around world. It seems to be an interesting source of bio-based molecules but, despite this potential, these byproducts are untapped. Their uses are limited to poor value added applications like composting, agricultural spreading or bioethanol.
This work focuses on the high value added valorization possibilities of the wine-making byproducts. It takes part in the current trend of using natural bioactive molecules in pharmaceutical, parapharmaceutical or food industry.
This study is built around three main objectives: a characterization of the raw material and the development of a method to extract polyphenols.
The results shown in this work tend to indicate a high valorization potential of grape pomace thank to the identification of interesting compounds like bioactive molecules and especially polyphenols as well as high concentrations of other molecules of which the valorization potential from wine-making byproducts needs to be explored
Ultrafast Lignin Extraction from Unusual Mediterranean Lignocellulosic Residues
Pretreatment is still the most expensive step in lignocellulosic biorefinery processes.
It must be made cost-effective by minimizing chemical requirements as well as power
and heat consumption and by using environment-friendly solvents. Deep eutectic
solvents (DESs) are key, green, and low-cost solvents in sustainable biorefineries.
They are transparent mixtures characterized by low freezing points resulting from at
least one hydrogen bond donor and one hydrogen bond acceptor. Although DESs
are promising solvents, it is necessary to combine them with an economic heating
technology, such as microwave irradiation, for competitive profitability. Microwave
irradiation is a promising strategy to shorten the heating time and boost fractionation
because it can rapidly attain the appropriate temperature. The aim of this study was to
develop a one-step, rapid method for biomass fractionation and lignin extraction using
a low-cost and biodegradable solvent.
In this study, a microwave-assisted DES pretreatment was conducted for 60 s at
800 W, using three kinds of DESs. The DES mixtures were facilely prepared from
choline chloride (ChCl) and three hydrogen-bond donors (HBDs): a monocarboxylic
acid (lactic acid), a dicarboxylic acid (oxalic acid), and urea. This pretreatment was
used for biomass fractionation and lignin recovery from marine residues (Posidonia
leaves and aegagropile), agri-food byproducts (almond shells and olive pomace),
forest residues (pinecones), and perennial lignocellulosic grasses (Stipa tenacissima).
Further analyses were conducted to determine the yield, purity, and molecular weight
distribution of the recovered lignin. In addition, the effect of DESs on the chemical
functional groups in the extracted lignin was determined by Fourier-transform infrared
(FTIR) spectroscopy. The results indicate that the ChCl-oxalic acid mixture affords the
highest lignin purity and the lowest yield. The present study demonstrates that the
DES-microwave process is an ultrafast, efficient, and cost-competitive technology for
lignocellulosic biomass fractionation
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