A genetic network that suppresses genome rearrangements in Saccharomyces cerevisiae and contains defects in cancers.

Gross chromosomal rearrangements (GCRs) play an important role in human diseases, including cancer. The identity of all Genome Instability Suppressing (GIS) genes is not currently known. Here multiple Saccharomyces cerevisiae GCR assays and query mutations were crossed into arrays of mutants to identify progeny with increased GCR rates. One hundred eighty two GIS genes were identified that suppressed GCR formation. Another 438 cooperatively acting GIS genes were identified that were not GIS genes, but suppressed the increased genome instability caused by individual query mutations. Analysis of TCGA data using the human genes predicted to act in GIS pathways revealed that a minimum of 93% of ovarian and 66% of colorectal cancer cases had defects affecting one or more predicted GIS gene. These defects included loss-of-function mutations, copy-number changes associated with reduced expression, and silencing. In contrast, acute myeloid leukaemia cases did not appear to have defects affecting the predicted GIS genes

Estudio del efecto del tamaño en la estructura cristalina de nanopartículas de CoFe2O4

Se estudió como afecta el tamaño de nanopartículas de ferrita de cobalto en el desorden cristalino por efecto de superficie. Las nanopartículas se obtuvieron por el método de coprecipitación de sales. Para controlar el tamaño realizaron diferentes tratamientos térmicos posteriores a la síntesis. La estructura cristalina y la morfología se evaluaron por medio de Difracción de rayos-X y Microscopía Electrónica de Transmisión de Alta Resolución. Los resultados obtenidos demuestran en forma cuantitativa, cómo la variación en la relación superficie/volumen es responsable de las deformaciones presentes en las nanoestructuras.Fil: Menchaca Nal, Sandra. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Tecnologia En Polimeros y Nanotecnologia; ArgentinaFil: Londoño Calderon, Cesar Leandro. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Tecnologia En Polimeros y Nanotecnologia; ArgentinaFil: Pardo Saavedra, D. C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería; ArgentinaFil: Pampillo, L. G.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería; ArgentinaFil: Socolovsky, Leandro Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería; ArgentinaFil: Martinez Garcia, Ricardo. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Tecnologia En Polimeros y Nanotecnologia; Argentin

Genetically engineered proteins with two active sites for enhanced biocatalysis and synergistic chemo- and biocatalysis

Enzyme engineering has allowed not only the de novo creation of active sites catalysing known biological reactions with rates close to diffusion limits, but also the generation of abiological sites performing new-to-nature reactions. However, the catalytic advantages of engineering multiple active sites into a single protein scaffold are yet to be established. Here, we report on proteins with two active sites of biological and/or abiological origin, for improved natural and non-natural catalysis. The approach increased the catalytic properties, such as enzyme efficiency, substrate scope, stereoselectivity and optimal temperature window, of an esterase containing two biological sites. Then, one of the active sites was metamorphosed into a metal-complex chemocatalytic site for oxidation and Friedel–Crafts alkylation reactions, facilitating synergistic chemo- and biocatalysis in a single protein. The transformations of 1-naphthyl acetate into 1,4-naphthoquinone (conversion approx. 100%) and vinyl crotonate and benzene into 3-phenylbutyric acid (≥83%; e.e. >99.9%) were achieved in one pot with this artificial multifunctional metalloenzyme.This work was funded by grant ‘INMARE’ from the European Union’s Horizon 2020 (grant agreement no. 634486), grants PCIN-2017-078 (within the Marine Biotechnology ERA-NET), CTQ2016-79138-R, BIO2016-76601-C3-1-R, BIO2016-76601-C3-3-R, BIO2017-85522-R, RTI2018-095166-B-I00 and RTI2018-095090-B-100 from the Ministerio de Economía y Competitividad, the Ministerio de Ciencia, Innovación y Universidades (MCIU), the Agencia Estatal de Investigación (AEI), the Fondo Europeo de Desarrollo Regional (FEDER) and the European Union (EU). P.N.G. and R.B. acknowledge the support of the UK Biotechnology and Biological Sciences Research Council (BBSRC; grant No. BB/M029085/1) and the Centre of Environmental Biotechnology Project and the Supercomputing Wales project, which are partly funded by the European Regional Development Fund (ERDF) through the Welsh Government. The authors gratefully acknowledge the financial support provided by the ERDF. C.C. thanks the Ministerio de Economía y Competitividad and FEDER for a Ph.D. fellowship (Grant BES-2015-073829). J.L.G.-A. thanks the support of the Spanish Ministry of Education, Culture and Sport through the National Program FPU (FPU17/00044). I.C.-R. thanks the Regional Government of Madrid for a fellowship (PEJ_BIO_AI_1201). The authors would like to acknowledge S. Ciordia and M. C. Mena for MALDI-TOF/TOF analysis. We thank the staff of both the European Synchrotron Radiation Facility (ESRF, Grenoble, France), for providing access and technical assistance at beamline ID30A-1/MASSIf-1, and the Synchrotron Radiation Source at Alba (Barcelona, Spain), for assistance at BL13-XALOC beamline. The authors would also like to acknowledge M. J. Vicente and M. A. Pascual at the Servicio Interdepartamental de Investigación (SIDI) of the Autonomous University of Madrid for the ESI-MS analyses

Parabacteroides distasonis:intriguing aerotolerant gut anaerobe with emerging antimicrobial resistance and pathogenic and probiotic roles in human health

Parabacteroides distasonis is the type strain for the genus Parabacteroides, a group of gram-negative anaerobic bacteria that commonly colonize the gastrointestinal tract of numerous species. First isolated in the 1930s from a clinical specimen as Bacteroides distasonis, the strain was re-classified to form the new genus Parabacteroides in 2006. Currently, the genus consists of 15 species, 10 of which are listed as 'validly named' (P. acidifaciens, P. chartae, P. chinchillae, P. chongii, P. distasonis, P. faecis, P. goldsteinii, P. gordonii, P. johnsonii, and P. merdae) and 5 'not validly named' (P. bouchesdurhonensis, P. massiliensis, P. pacaensis, P. provencensis, and P. timonensis) by the List of Prokaryotic names with Standing in Nomenclature. The Parabacteroides genus has been associated with reports of both beneficial and pathogenic effects in human health. Herein, we review the literature on the history, ecology, diseases, antimicrobial resistance, and genetics of this bacterium, illustrating the effects of P. distasonis on human and animal health

CERT\u3csub\u3eL\u3c/sub\u3e Reduces C16 Ceramide, Amyloid-β Levels, and Inflammation in a Model of Alzheimer’s Disease

BACKGROUND: Dysregulation of ceramide and sphingomyelin levels have been suggested to contribute to the pathogenesis of Alzheimer\u27s disease (AD). Ceramide transfer proteins (CERTs) are ceramide carriers which are crucial for ceramide and sphingomyelin balance in cells. Extracellular forms of CERTs co-localize with amyloid-β (Aβ) plaques in AD brains. To date, the significance of these observations for the pathophysiology of AD remains uncertain. METHODS: A plasmid expressing CERTL, the long isoform of CERTs, was used to study the interaction of CERTL with amyloid precursor protein (APP) by co-immunoprecipitation and immunofluorescence in HEK cells. The recombinant CERTL protein was employed to study interaction of CERTL with amyloid-β (Aβ), Aβ aggregation process in presence of CERTL, and the resulting changes in Aβ toxicity in neuroblastoma cells. CERTL was overexpressed in neurons by adeno-associated virus (AAV) in a mouse model of familial AD (5xFAD). Ten weeks after transduction, animals were challenged with behavior tests for memory, anxiety, and locomotion. At week 12, brains were investigated for sphingolipid levels by mass spectrometry, plaques, and neuroinflammation by immunohistochemistry, gene expression, and/or immunoassay. RESULTS: Here, we report that CERTL binds to APP, modifies Aβ aggregation, and reduces Aβ neurotoxicity in vitro. Furthermore, we show that intracortical injection of AAV, mediating the expression of CERTL, decreases levels of ceramide d18:1/16:0 and increases sphingomyelin levels in the brain of male 5xFAD mice. CERTL in vivo over-expression has a mild effect on animal locomotion, decreases Aβ formation, and modulates microglia by decreasing their pro-inflammatory phenotype. CONCLUSION: Our results demonstrate a crucial role of CERTL in regulating ceramide levels in the brain, in amyloid plaque formation and neuroinflammation, thereby opening research avenues for therapeutic targets of AD and other neurodegenerative diseases

Protection characteristics of a Faraday cage compromised by lightning burnthrough.

A lightning flash consists of multiple, high-amplitude but short duration return strokes. Between the return strokes is a lower amplitude, continuing current which flows for longer duration. If the walls of a Faraday cage are made of thin enough metal, the continuing current can melt a hole through the metal in a process called burnthrough. A subsequent return stroke can couple energy through this newly-formed hole. This LDRD is a study of the protection provided by a Faraday cage when it has been compromised by burnthrough. We initially repeated some previous experiments and expanded on them in terms of scope and diagnostics to form a knowledge baseline of the coupling phenomena. We then used a combination of experiment, analysis and numerical modeling to study four coupling mechanisms: indirect electric field coupling, indirect magnetic field coupling, conduction through plasma and breakdown through the hole. We discovered voltages higher than those encountered in the previous set of experiments (on the order of several hundreds of volts)

Carcinoma-derived interleukin-8 disorients dendritic cell migration without impairing T-cell stimulation

BACKGROUND: Interleukin-8 (IL-8, CXCL8) is readily produced by human malignant cells. Dendritic cells (DC) both produce IL-8 and express the IL-8 functional receptors CXCR1 and CXCR2. Most human colon carcinomas produce IL-8. IL-8 importance in malignancies has been ascribed to angiogenesis promotion. PRINCIPAL FINDINGS: IL-8 effects on human monocyte-derived DC biology were explored upon DC exposure to recombinant IL-8 and with the help of an IL-8 neutralizing mAb. In vivo experiments were performed in immunodeficient mice xenografted with IL-8-producing human colon carcinomas and comparatively with cell lines that do not produce IL-8. Allogenic T lymphocyte stimulation by DC was explored under the influence of IL-8. DC and neutrophil chemotaxis were measured by transwell-migration assays. Sera from tumor-xenografted mice contained increasing concentrations of IL-8 as the tumors progress. IL-8 production by carcinoma cells can be modulated by low doses of cyclophosphamide at the transcription level. If human DC are injected into HT29 or CaCo2 xenografted tumors, DC are retained intratumorally in an IL-8-dependent fashion. However, IL-8 did not modify the ability of DC to stimulate T cells. Interestingly, pre-exposure of DC to IL-8 desensitizes such cells for IL-8-mediated in vitro or in vivo chemoattraction. Thereby DC become disoriented to subsequently follow IL-8 chemotactic gradients towards malignant or inflamed tissue. CONCLUSIONS: IL-8 as produced by carcinoma cells changes DC migration cues, without directly interfering with DC-mediated T-cell stimulation