Uterine selection of human embryos at implantation

Human embryos frequently harbor large-scale complex chromosomal errors that impede normal development. Affected embryos may fail to implant although many first breach the endometrial epithelium and embed in the decidualizing stroma before being rejected via mechanisms that are poorly understood. Here we show that developmentally impaired human embryos elicit an endoplasmic stress response in human decidual cells. A stress response was also evident upon in vivo exposure of mouse uteri to culture medium conditioned by low-quality human embryos. By contrast, signals emanating from developmentally competent embryos activated a focused gene network enriched in metabolic enzymes and implantation factors. We further show that trypsin, a serine protease released by pre-implantation embryos, elicits Ca2+ signaling in endometrial epithelial cells. Competent human embryos triggered short-lived oscillatory Ca2+ fluxes whereas low-quality embryos caused a heightened and prolonged Ca2+ response. Thus, distinct positive and negative mechanisms contribute to active selection of human embryos at implantation

Study protocol: developing a decision system for inclusive housing: applying a systematic, mixed-method quasi-experimental design

Background Identifying the housing preferences of people with complex disabilities is a much needed, but under-developed area of practice and scholarship. Despite the recognition that housing is a social determinant of health and quality of life, there is an absence of empirical methodologies that can practically and systematically involve consumers in this complex service delivery and housing design market. A rigorous process for making effective and consistent development decisions is needed to ensure resources are used effectively and the needs of consumers with complex disability are properly met. Methods/Design This 3-year project aims to identify how the public and private housing market in Australia can better respond to the needs of people with complex disabilities whilst simultaneously achieving key corporate objectives. First, using the Customer Relationship Management framework, qualitative (Nominal Group Technique) and quantitative (Discrete Choice Experiment) methods will be used to quantify the housing preferences of consumers and their carers. A systematic mixed-method, quasi-experimental design will then be used to quantify the development priorities of other key stakeholders (e.g., architects, developers, Government housing services etc.) in relation to inclusive housing for people with complex disabilities. Stakeholders randomly assigned to Group 1 (experimental group) will participate in a series of focus groups employing Analytical Hierarchical Process (AHP) methodology. Stakeholders randomly assigned to Group 2 (control group) will participate in focus groups employing existing decision making processes to inclusive housing development (e.g., Risk, Opportunity, Cost, Benefit considerations). Using comparative stakeholder analysis, this research design will enable the AHP methodology (a proposed tool to guide inclusive housing development decisions) to be tested. Discussion It is anticipated that the findings of this study will enable stakeholders to incorporate consumer housing preferences into commercial decisions. Housing designers and developers will benefit from the creation of a parsimonious set of consumer-led housing preferences by which to make informed investments in future housing and contribute to future housing policy. The research design has not been applied in the Australian research context or elsewhere, and will provide a much needed blueprint for market investment to develop viable, consumer directed inclusive housing options for people with complex disability

The Location and Nature of General Anesthetic Binding Sites on the Active Conformation of Firefly Luciferase; A Time Resolved Photolabeling Study

Firefly luciferase is one of the few soluble proteins that is acted upon by a wide variety of general anesthetics and alcohols; they inhibit the ATP–driven production of light. We have used time–resolved photolabeling to locate the binding sites of alcohols during the initial light output, some 200 ms after adding ATP. The photolabel 3-azioctanol inhibited the initial light output with an IC50 of 200 µM, close to its general anesthetic potency. Photoincorporation of [3H]3-azioctanol into luciferase was saturable but weak. It was enhanced 200 ms after adding ATP but was negligible minutes later. Sequencing of tryptic digests by HPLC–MSMS revealed a similar conformation–dependence for photoincorporation of 3-azioctanol into Glu-313, a residue that lines the bottom of a deep cleft (vestibule) whose outer end binds luciferin. An aromatic diazirine analog of benzyl alcohol with broader side chain reactivity reported two sites. First, it photolabeled two residues in the vestibule, Ser-286 and Ile-288, both of which are implicated with Glu-313 in the conformation change accompanying activation. Second, it photolabeled two residues that contact luciferin, Ser-316 and Ser-349. Thus, time resolved photolabeling supports two mechanisms of action. First, an allosteric one, in which anesthetics bind in the vestibule displacing water molecules that are thought to be involved in light output. Second, a competitive one, in which anesthetics bind isosterically with luciferin. This work provides structural evidence that supports the competitive and allosteric actions previously characterized by kinetic studies

Reducing the Activity and Secretion of Microbial Antioxidants Enhances the Immunogenicity of BCG

BACKGROUND:In early clinical studies, the live tuberculosis vaccine Mycobacterium bovis BCG exhibited 80% protective efficacy against pulmonary tuberculosis (TB). Although BCG still exhibits reliable protection against TB meningitis and miliary TB in early childhood it has become less reliable in protecting against pulmonary TB. During decades of in vitro cultivation BCG not only lost some genes due to deletions of regions of the chromosome but also underwent gene duplication and other mutations resulting in increased antioxidant production. METHODOLOGY/PRINCIPAL FINDINGS:To determine whether microbial antioxidants influence vaccine immunogenicity, we eliminated duplicated alleles encoding the oxidative stress sigma factor SigH in BCG Tice and reduced the activity and secretion of iron co-factored superoxide dismutase. We then used assays of gene expression and flow cytometry with intracellular cytokine staining to compare BCG-specific immune responses in mice after vaccination with BCG Tice or the modified BCG vaccine. Compared to BCG, the modified vaccine induced greater IL-12p40, RANTES, and IL-21 mRNA in the spleens of mice at three days post-immunization, more cytokine-producing CD8+ lymphocytes at the peak of the primary immune response, and more IL-2-producing CD4+ lymphocytes during the memory phase. The modified vaccine also induced stronger secondary CD4+ lymphocyte responses and greater clearance of challenge bacilli. CONCLUSIONS/SIGNIFICANCE:We conclude that antioxidants produced by BCG suppress host immune responses. These findings challenge the hypothesis that the failure of extensively cultivated BCG vaccines to prevent pulmonary tuberculosis is due to over-attenuation and suggest instead a new model in which BCG evolved to produce more immunity-suppressing antioxidants. By targeting these antioxidants it may be possible to restore BCG's ability to protect against pulmonary TB

FE65 Binds Teashirt, Inhibiting Expression of the Primate-Specific Caspase-4

The Alzheimer disease (AD) amyloid protein precursor (APP) can bind the FE65 adaptor protein and this complex can regulate gene expression. We carried out yeast two-hybrid studies with a PTB domain of FE65, focusing on those genes that might be involved in nuclear signaling, and identified and validated Teashirt proteins as FE65 interacting proteins in neurons. Using reporter systems, we observed that FE65 could simultaneously recruit SET, a component of the inhibitor of acetyl transferase, and Teashirt, which in turn recruited histone deacetylases, to produce a powerful gene-silencing complex. We screened stable cell lines with a macroarray focusing on AD-related genes and identified CASP4, encoding caspase-4, as a target of this silencing complex. Chromatin immunoprecipitation showed a direct interaction of FE65 and Teashirt3 with the promoter region of CASP4. Expression studies in postmortem samples demonstrated decreasing expression of Teashirt and increasing expression of caspase-4 with progressive cognitive decline. Importantly, there were significant increases in caspase-4 expression associated with even the earliest neuritic plaque changes in AD. We evaluated a case-control cohort and observed evidence for a genetic association between the Teashirt genes TSHZ1 and TSHZ3 and AD, with the TSHZ3 SNP genotype correlating with expression of Teashirt3. The results were consistent with a model in which reduced expression of Teashirt3, mediated by genetic or other causes, increases caspase-4 expression, leading to progression of AD. Thus the cell biological, gene expression and genetic data support a role for Teashirt/caspase-4 in AD biology. As caspase-4 shows evidence of being a primate-specific gene, current models of AD and other neurodegenerative conditions may be incomplete because of the absence of this gene in the murine genome

Microglial activation and chronic neurodegeneration

Microglia, the resident innate immune cells in the brain, have long been implicated in the pathology of neurode-generative diseases. Accumulating evidence points to activated microglia as a chronic source of multiple neurotoxic factors, including tumor necrosis factor-α, nitric oxide, interleukin-1β, and reactive oxygen species (ROS), driving progressive neuron damage. Microglia can become chronically activated by either a single stimulus (e.g., lipopolysaccharide or neuron damage) or multiple stimuli exposures to result in cumulative neuronal loss with time. Although the mechanisms driving these phenomena are just beginning to be understood, reactive microgliosis (the microglial response to neuron damage) and ROS have been implicated as key mechanisms of chronic and neurotoxic microglial activation, particularly in the case of Parkinson’s disease. We review the mechanisms of neurotoxicity associated with chronic microglial activation and discuss the role of neuronal death and microglial ROS driving the chronic and toxic microglial phenotype

Identification of low oxygen-tolerating bacteria in prostate secretions of cancer patients and discussion of possible aetiological significance

MW was in receipt of Barts and The London Charity Equipment Grant for provision of MOLDI-TOF (Grant reference number 486/1193)

Hot atmospheres of galaxies, groups, and clusters of galaxies

Most of the ordinary matter in the local Universe has not been converted into stars but resides in a largely unexplored diffuse, hot, X-ray emitting plasma. It pervades the gravitational potentials of massive galaxies, groups and clusters of galaxies, as well as the filaments of the cosmic web. The physics of this hot medium, such as its dynamics, thermodynamics and chemical composition can be studied using X-ray spectroscopy in great detail. Here, we present an overview of the basic properties and discuss the self similarity of the hot "atmospheres" permeating the gravitational halos from the scale of galaxies, through groups, to massive clusters. Hot atmospheres are stabilised by the activity of supermassive black holes and, in many ways, they are of key importance for the evolution of their host galaxies. The hot plasma has been significantly enriched in heavy elements by supernovae during the period of maximum star formation activity, probably more than 10 billion years ago. High resolution X-ray spectroscopy just started to be able to probe the dynamics of atmospheric gas and future space observatories will determine the properties of the currently unseen hot diffuse medium throughout the cosmic web.Comment: Accepted for publication in the book "Reviews in Frontiers of Modern Astrophysics: From Space Debris to Cosmology" (eds Kabath, Jones and Skarka; publisher Springer Nature) funded by the European Union Erasmus+ Strategic Partnership grant "Per Aspera Ad Astra Simul" 2017-1-CZ01-KA203-03556