Catalytically inactive human cathepsin D triggers fibroblast invasive growth

The aspartyl-protease cathepsin D (cath-D) is overexpressed and hypersecreted by epithelial breast cancer cells and stimulates their proliferation. As tumor epithelial–fibroblast cell interactions are important events in cancer progression, we investigated whether cath-D overexpression affects also fibroblast behavior. We demonstrate a requirement of cath-D for fibroblast invasive growth using a three-dimensional (3D) coculture assay with cancer cells secreting or not pro-cath-D. Ectopic expression of cath-D in cath-D–deficient fibroblasts stimulates 3D outgrowth that is associated with a significant increase in fibroblast proliferation, survival, motility, and invasive capacity, accompanied by activation of the ras–MAPK pathway. Interestingly, all these stimulatory effects on fibroblasts are independent of cath-D proteolytic activity. Finally, we show that pro-cath-D secreted by cancer cells is captured by fibroblasts and partially mimics effects of transfected cath-D. We conclude that cath-D is crucial for fibroblast invasive outgrowth and could act as a key paracrine communicator between cancer and stromal cells, independently of its catalytic activity

A critical appraisal of guidelines for the management of knee osteoarthritis using Appraisal of Guidelines Research and Evaluation criteria

Clinical practice guidelines have been elaborated to summarize evidence related to the management of knee osteoarthritis and to facilitate uptake of evidence-based knowledge by clinicians. The objectives of the present review were summarizing the recommendations of existing guidelines on knee osteoarthritis, and assessing the quality of the guidelines using a standardized and validated instrument – the Appraisal of Guidelines Research and Evaluation (AGREE) tool. Internet medical literature databases from 2001 to 2006 were searched for guidelines, with six guidelines being identified. Thirteen clinician researchers participated in the review. Each reviewer was trained in the AGREE instrument. The guidelines were distributed to four groups of three or four reviewers, each group reviewing one guideline with the exception of one group that reviewed two guidelines. One independent evaluator reviewed all guidelines. All guidelines effectively addressed only a minority of AGREE domains. Clarity/presentation was effectively addressed in three out of six guidelines, scope/purpose and rigour of development in two guidelines, editorial independence in one guideline, and stakeholder involvement and applicability in none. The clinical management recommendation tended to be similar among guidelines, although interventions addressed varied. Acetaminophen was recommended for initial pain treatment, combined with exercise and education. Nonsteroidal anti-inflammatory drugs were recommended if acetaminophen failed to control pain, but cautiously because of gastrointestinal risks. Surgery was recommended in the presence of persistent pain and disability. Education and activity management interventions were superficially addressed in most guidelines. Guideline creators should use the AGREE criteria when developing guidelines. Innovative and effective methods of knowledge translation to health professionals are needed

Strategies and impacts of patient and family engagement in collaborative mental healthcare: protocol for a systematic and realist review

INTRODUCTION: Collaborative mental healthcare (CMHC) has garnered worldwide interest as an effective, team-based approach to managing common mental disorders in primary care. However, questions remain about how CMHC works and why it works in some circumstances but not others. In this study, we will review the evidence on one understudied but potentially critical component of CMHC, namely the engagement of patients and families in care. Our aims are to describe the strategies used to engage people with depression or anxiety disorders and their families in CMHC and understand how these strategies work, for whom and in what circumstances. METHODS AND ANALYSIS: We are conducting a review with systematic and realist review components. Review part 1 seeks to identify and describe the patient and family engagement strategies featured in CMHC interventions based on systematic searches and descriptive analysis of these interventions. We will use a 2012 Cochrane review of CMHC as a starting point and perform new searches in multiple databases and trial registers to retrieve more recent CMHC intervention studies. In review part 2, we will build and refine programme theories for each of these engagement strategies. Initial theory building will proceed iteratively through content expert consultations, electronic searches for theoretical literature and review team brainstorming sessions. Cluster searches will then retrieve additional data on contexts, mechanisms and outcomes associated with engagement strategies, and pairs of review authors will analyse and synthesise the evidence and adjust initial programme theories. ETHICS AND DISSEMINATION: Our review follows a participatory approach with multiple knowledge users and persons with lived experience of mental illness. These partners will help us develop and tailor project outputs, including publications, policy briefs, training materials and guidance on how to make CMHC more patient-centred and family-centred

Sequence-selective assembly of tweezer-molecules on linear templates enables frameshift-reading of sequence information

Monomer-sequence information in synthetic copolyimides can be recognised by tweezer-type molecules binding to adjacent triplet-sequences on the polymer chains. In the present paper different tweezer-molecules are found to have different sequence-selectivities, as demonstrated in solution by 1H NMR spectroscopy and in the solid state by single crystal X-ray analyses of tweezer-complexes with linear and macrocyclic oligo-imides. This work provides clear-cut confirmation of polyimide chain-folding and adjacent-tweezer-binding. It also reveals a new and entirely unexpected mechanism for sequence-recognition which, by analogy with a related process in biomolecular information processing, may be termed "frameshift-reading". The ability of one particular tweezer-molecule to detect, with exceptionally high sensitivity, long-range sequence-information in chain-folding aromatic copolyimides, is readily explained by this novel process

The extraordinary March 2022 East Antarctica "heat" wave. Part I: observations and meteorological drivers

peer reviewe

The extraordinary March 2022 East Antarctica "heat" wave. Part II: impacts on the Antarctic ice sheet

peer reviewe

Control of oxidative metabolism of leukemic cells by the bone marrow microenvironment

Des études menées sur des modèles animaux ont montré que le métabolisme oxydatif joue un rôle important dans l’hématopoïèse normale et leucémique via le contrôle de l’activation de p38 MAPK. Nous avons établi que les cellules CD34+CD38- médullaires humaines ont un très faible niveau d’H2O2 et une forte expression de GPX3, le gène codant l’enzyme antioxydante glutathion peroxydase-3 (GPx-3), un déterminant majeur du potentiel souche des cellules hématopoïétiques. De plus, la niche leucémique étant essentielle pour l’auto-renouvellement des cellules souches leucémiques, nous avons étudié, chez l’homme, le rôle des cellules souches/stromales mésenchymateuses (CSM) médullaires primaires, dans la régulation de l’axe GPx-3/H2O2/p38 MAPK des cellules leucémiques et avons montré que les CSM contrôlent cet axe dans les cellules leucémiques humaines KG1a en régulant l’expression de GPx-3. Ces résultats ont bénéficié du développement de deux méthodes originales, l’une quantifiant l’expression des gènes antioxydants par RT-qPCR (« antioxydogramme », brevet) et l’autre permettant une analyse en haute résolution du cycle cellulaire par cytométrie en flux.Studies in animal models have demonstrated that oxidative metabolism plays an important role in normal and leukemic hematopoiesis by controlling the p38 MAPK activation. We have established that the human bone marrow CD34+CD38- cells have a very low H2O2 level and express GPX3, the gene encoding for the antioxidative enzyme gluthathione peroxidase-3 (GPx-3) which is a major determinant of the stem cell potential of hematopoietic cells. As the niche is essential for the leukemic stem cell self-renewal, we have studied the role of human primary bone marrow mesenchymal stromal/stem cells (MSCs) in regulating the axis GPx-3/H2O2/p38 MAPK in human leukemic cells and we have shown that MSCs control this axis in human KG1a leukemic cells by regulating the expression of GPx-3. These results benefited from the development of two original methods, the first one quantifying the expression of by RT-qPCR of antioxidative genes (“antioxidogram”, patent) and the second one for high resolution analysis of the cell cycle by flow cytometry

Le plateau de microscopie électronique à transmission de l'Inra de Jouy-en-Josas

National audienceLe plateau technique de microscopie électronique à transmission est un des trois plateaux d'imagerie qui constituent la plateforme d'imagerie MIMA2 (Microscopie et Imagerie des Micro-organismes, Animaux et Aliments). La plate-forme est par ailleurs équipée d'appareils dédiés à la microscopie optique (confocal et apotome) et à la microscopie électronique à balayage. Cette structure est ouverte aux équipes extérieures au site. Les projets développés en interne sur cette plate-forme concernent avant tout l'animal et les procaryotes (bactéries). Les personnels du plateau offre la possibilité d'apprendre la préparation des échantillons et des formations sur les techniques d'observation en microscopie électronique. Ces techniques peuvent être appliquées et adaptées dans les différentes unités de recherche à divers projets et objets pour une observation à l'échelle 28 subcellulaire. Le plateau met en place des approches de microscopie corrélative pour des questions de biologie cellulaire et du développement. Des approches d’analyse élémentaires (EELS et PEELS) sont également réalisées au sein du plateau de microscopie sur un microscope ZEISS EM902, équipé d’un filtre alpha de perte d’énergie. La structure, l'activité et quelques exemples d'études réalisées par le plateau technique sont décrits

Protein-tyrosine Phosphatase PTPL1/FAP-1 Triggers Apoptosis in Human Breast Cancer Cells

International audienceStudies in Jurkat leukemia cells have suggested that protein-tyrosine phosphatase PTPL1/FAP-1 rescues Fas-induced cell death. However, we have previously shown that this enzyme triggers 4-hydroxytamoxifen-induced growth inhibition in human breast cancer cells. The present study addresses the role of PTPL1/FAP-1 in antiestrogen-regulated apoptotic effect and insulin-like growth factor-I survival action in MCF7 cells and further identifies the impacted signaling pathway. By terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling and cytoplasmic nucleosome enzyme-linked immunosorbent assay, we demonstrated that 4-hydroxytamoxifen-induced apoptosis was totally lost in PTPL1/FAP-1 antisense transfectants in which enzyme expression was abrogated, revealing the crucial role of this phosphatase in the apoptotic process in human breast cancer cells. Time-dependent expression of PTPL1/FAP-1 in MCF7 cells completely abolished the survival action of insulin-like growth factor-I. This effect occurred through a highly significant reduction in phosphatidylinositol 3-kinase/Akt pathway activation (80% reduction in phosphatidylinositol 3-kinase activity, 55% inhibition of Akt activation) accompanied by a 65% decrease in insulin receptor substrate-1 growth factor-induced tyrosine phosphorylation. These results provide the first evidence that PTPL1/FAP-1 has a key role in the apoptotic process in human breast cancer cells independent of Fas but associated with an early inhibition of the insulin receptor substrate-1/phosphatidylinositol 3-kinase pathway. Our data therefore suggest new therapeutic routes and strengthen the importance of identifying endogenous regulators and substrates of this phosphatase in breast tumors