Transcription Factor Nrf1 Mediates the Proteasome Recovery Pathway after Proteasome Inhibition in Mammalian Cells

In Saccharomyces cerevisiae, chemical or genetic inhibition of proteasome activity induces new proteasome synthesis promoted by the transcription factor RPN4. This ensures that proteasome activity is matched to demand. This transcriptional feedback loop is conserved in mammals, but its molecular basis is not understood. Here, we report that nuclear factor erythroid-derived 2-related factor 1 (Nrf1), a transcription factor of the cap “n” collar basic leucine zipper family, but not the related Nrf2, is necessary for induced proteasome gene transcription in mouse embryonic fibroblasts (MEFs). Promoter-reporter assays revealed the importance of antioxidant response elements in Nrf1-mediated upregulation of proteasome subunit genes. Nrf1^(−/−) MEFs were impaired in the recovery of proteasome activity after transient treatment with the covalent proteasome inhibitor YU101, and knockdown of Nrf1 in human cancer cells enhanced cell killing by YU101. Taken together, our results suggest that Nrf1-mediated proteasome homeostasis could be an attractive target for therapeutic intervention in cancer

The Oct1 homolog Nubbin is a repressor of NF-κB-dependent immune gene expression that increases the tolerance to gut microbiota

Background: Innate immune responses are evolutionarily conserved processes that provide crucial protection against invading organisms. Gene activation by potent NF-κB transcription factors is essential both in mammals and Drosophila during infection and stress challenges. If not strictly controlled, this potent defense system can activate autoimmune and inflammatory stress reactions, with deleterious consequences for the organism. Negative regulation to prevent gene activation in healthy organisms, in the presence of the commensal gut flora, is however not well understood. Results: We show that the Drosophila homolog of mammalian Oct1/POU2F1 transcription factor, called Nubbin (Nub), is a repressor of NF-κB/Relish-driven antimicrobial peptide gene expression in flies. In nub mutants, which lack Nub-PD protein, excessive expression of antimicrobial peptide genes occurs in the absence of infection, leading to a significant reduction of the numbers of cultivatable gut commensal bacteria. This aberrant immune gene expression was effectively blocked by expression of Nub from a transgene. We have identified an upstream regulatory region, containing a cluster of octamer sites, which is required for repression of antimicrobial peptide gene expression in healthy flies. Chromatin immunoprecipitation experiments demonstrated that Nub binds to octamer-containing promoter fragments of several immune genes. Gene expression profiling revealed that Drosophila Nub negatively regulates many genes that are involved in immune and stress responses, while it is a positive regulator of genes involved in differentiation and metabolism. Conclusions: This study demonstrates that a large number of genes that are activated by NF-κB/Relish in response to infection are normally repressed by the evolutionarily conserved Oct/POU transcription factor Nub. This prevents uncontrolled gene activation and supports the existence of a normal gut flora. We suggest that Nub protein plays an ancient role, shared with mammalian Oct/POU transcription factors, to moderate responses to immune challenge, thereby increasing the tolerance to biotic stress

Bridging consent: from toll bridges to lift bridges?

<p>Abstract</p> <p>Background</p> <p>The ability to share human biological samples, associated data and results across disease-specific and population-based human research biobanks is becoming increasingly important for research into disease development and translation. Although informed consent often does not anticipate such cross-domain sharing, it is important to examine its plausibility. The purpose of this study was to explore the feasibility of bridging consent between disease-specific and population-based research. Comparative analyses of 1) current ethical and legal frameworks governing consent and 2) informed consent models found in disease-specific and population-based research were conducted.</p> <p>Discussion</p> <p>Ethical and legal frameworks governing consent dissuade cross-domain data sharing. Paradoxically, analysis of consent models for disease-specific and population-based research reveals such a high degree of similarity that bridging consent could be possible if additional information regarding bridging was incorporated into consent forms. We submit that bridging of consent could be supported if current trends endorsing a new interpretation of consent are adopted. To illustrate this we sketch potential bridging consent scenarios.</p> <p>Summary</p> <p>A bridging consent, respectful of the spirit of initial consent, is feasible and would require only small changes to the content of consents currently being used. Under a bridging consent approach, the initial data and samples collection can serve an identified research project as well as contribute to the creation of a resource for a range of other projects.</p

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Basic Leucine Zipper Protein Cnc-C Is a Substrate and Transcriptional Regulator of the Drosophila 26S Proteasome▿ †

While the 26S proteasome is a key proteolytic complex, little is known about how proteasome levels are maintained in higher eukaryotic cells. Here we describe an RNA interference (RNAi) screen of Drosophila melanogaster that was used to identify transcription factors that may play a role in maintaining levels of the 26S proteasome. We used an RNAi library against 993 Drosophila transcription factor genes to identify genes whose suppression in Schneider 2 cells stabilized a ubiquitin-green fluorescent protein reporter protein. This screen identified Cnc (cap 'n’ collar [CNC]; basic region leucine zipper) as a candidate transcriptional regulator of proteasome component expression. In fact, 20S proteasome activity was reduced in cells depleted of cnc. Immunoblot assays against proteasome components revealed a general decline in both 19S regulatory complex and 20S proteasome subunits after RNAi depletion of this transcription factor. Transcript-specific silencing revealed that the longest of the seven transcripts for the cnc gene, cnc-C, was needed for proteasome and p97 ATPase production. Quantitative reverse transcription-PCR confirmed the role of Cnc-C in activation of transcription of genes encoding proteasome components. Expression of a V5-His-tagged form of Cnc-C revealed that the transcription factor is itself a proteasome substrate that is stabilized when the proteasome is inhibited. We propose that this single cnc gene in Drosophila resembles the ancestral gene family of mammalian nuclear factor erythroid-derived 2-related transcription factors, which are essential in regulating oxidative stress and proteolysis

Get One or Create One: The Impact of Graded Involvement in a Selection Procedure for a Virtual Agent on Satisfaction and Suitability Ratings

Diehl C, Schiffhauer B, Eyssel FA, et al. Get One or Create One: The Impact of Graded Involvement in a Selection Procedure for a Virtual Agent on Satisfaction and Suitability Ratings. In: Beskow J, Peters C, Castellano G, Leite I, Kopp S, eds. Proceedings of the 17th International Conference on Intelligent Virtual Agents. Springer International Publishing; 2017: 109-118

Identification of Fluorescent Small Molecule Compounds for Synaptic Labeling by Image-Based, High-Content Screening

Few tools are available for noninvasive imaging of synapses in the living mammalian brain. Current paradigms require the use of genetically modified mice or viral delivery of genetic material to the brain. To develop an alternative chemical approach, utilizing the recognition of synaptic components by organic small molecules, we designed an imaging-based, high-content screen in cultured cortical neurons to identify molecules based on their colocalization with fluorescently tagged synaptic proteins. We used this approach to screen a library of similar to 7000 novel fluorescent dyes, and identified a series of compounds in the xanthone family that exhibited consistent synaptic labeling. Follow-up studies with one of these compounds, CX-G3, demonstrated its ability to label acidic organelles and in particular synaptic vesicles at glutamatergic synapses in cultured neurons and murine brain tissue, indicating the potential of this screening approach to identify promising lead compounds for use as synaptic markers, sensors, and targeting devices.110sciescopu

Differences between children and adolescents who commit suicide and their peers: A psychological autopsy of suicide victims compared to accident victims and a community sample

<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to gain knowledge about the circumstances related to suicide among children and adolescents 15 years and younger.</p> <p>Methods</p> <p>We conducted a psychological autopsy, collecting information from parents, hospital records and police reports on persons below the age of 16 who had committed suicide in Norway during a 12-year period (1993-2004) (n = 41). Those who committed suicide were compared with children and adolescents who were killed in accidents during the same time period (n = 43) and with a community sample. <b>Results: </b>Among the suicides 25% met the criteria for a psychiatric diagnosis and 30% had depressive symptoms at the time of death. Furthermore, 60% of the parents of the suicide victims reported the child experienced some kind of stressful conflict prior to death, whereas only 12% of the parents of the accident victims reported such conflicts.</p> <p>Conclusion</p> <p>One in four suicide victims fulfilled the criteria for a psychiatric diagnosis. The level of sub-threshold depression and of stressful conflict experienced by youths who committed suicide did not appear to differ substantially from that of their peers, and therefore did not raise sufficient concern for referral to professional help.</p