Zebrafish as a model for cardiac disease; Cryo-EM structure of native cardiac thin filaments from Danio Rerio.

Actin, tropomyosin and troponin, the proteins that comprise the contractile apparatus of the cardiac thin filament, are highly conserved across species. We have used cryo-EM to study the three-dimensional structure of the zebrafish cardiac thin and actin filaments. With 70% of human genes having an obvious zebrafish orthologue, and conservation of 85% of disease-causing genes, zebrafish are a good animal model for the study of human disease. Our structure of the zebrafish thin filament reveals the molecular interactions between the constituent proteins, showing that the fundamental organisation of the complex is the same as that reported in the human reconstituted thin filament. A reconstruction of zebrafish cardiac F-actin demonstrates no deviations from human cardiac actin over an extended length of 14 actin subunits. Modelling zebrafish homology models into our maps enabled us to compare, in detail, the similarity with human models. The structural similarities of troponin-T in particular, a region known to contain a hypertrophic cardiomyopathy 'hotspot', confirm the suitability of zebrafish to study these disease-causing mutations

Regulation of inositol 5-phosphatase activity by the C2 domain of SHIP1 and SHIP2

SHIP1, an inositol 5-phosphatase, plays a central role in cellular signaling. As such, it has been implicated in many conditions. Exploiting SHIP1 as a drug target will require structural knowledge and the design of selective small molecules. We have determined apo, and magnesium and phosphate-bound structures of the phosphatase and C2 domains of SHIP1. The C2 domains of SHIP1 and the related SHIP2 modulate the activity of the phosphatase domain. To understand the mechanism, we performed activity assays, hydrogen-deuterium exchange mass spectrometry, and molecular dynamics on SHIP1 and SHIP2. Our findings demonstrate that the influence of the C2 domain is more pronounced for SHIP2 than SHIP1. We determined 91 structures of SHIP1 with fragments bound, with some near the interface between the two domains. We performed a mass spectrometry screen and determined four structures with covalent fragments. These structures could act as starting points for the development of potent, selective probes

Transcriptional analysis of defense mechanisms in upland tetraploid switchgrass to greenbugs

Background: Aphid infestation of switchgrass (Panicum virgatum) has the potential to reduce yields and biomass quality. Although switchgrass-greenbug (Schizaphis graminum; GB) interactions have been studied at the whole plant level, little information is available on plant defense responses at the molecular level. Results: The global transcriptomic response of switchgrass cv Summer to GB was monitored by RNA-Seq in infested and control (uninfested) plants harvested at 5, 10, and 15 days after infestation (DAI). Differentially expressed genes (DEGs) in infested plants were analyzed relative to control uninfested plants at each time point. DEGs in GB-infested plants induced by 5-DAI included an upregulation of reactive burst oxidases and several cell wall receptors. Expression changes in genes linked to redox metabolism, cell wall structure, and hormone biosynthesis were also observed by 5- DAI. At 10-DAI, network analysis indicated a massive upregulation of defense-associated genes, including NAC, WRKY, and MYB classes of transcription factors and potential ancillary signaling molecules such as leucine aminopeptidases. Molecular evidence for loss of chloroplastic functions was also detected at this time point. Supporting these molecular changes, chlorophyll content was significantly decreased, and ROS levels were elevated in infested plants 10-DAI. Total peroxidase and laccase activities were elevated in infested plants at 10-DAI relative to control uninfested plants. The net result appeared to be a broad scale defensive response that led to an apparent reduction in C and N assimilation and a potential redirection of nutrients away from GB and towards the production of defensive compounds, such as pipecolic acid, chlorogenic acid, and trehalose by 10-DAI. By 15-DAI, evidence of recovery in primary metabolism was noted based on transcript abundances for genes associated with carbon, nitrogen, and nutrient assimilation. Conclusions: Extensive remodeling of the plant transcriptome and the production of ROS and several defensive metabolites in an upland switchgrass cultivar were observed in response to GB feeding. The early loss and apparent recovery in primary metabolism by 15-DAI would suggest that these transcriptional changes in later stages of GB infestation could underlie the recovery response categorized for this switchgrass cultivar. These results can be exploited to develop switchgrass lines with more durable resistance to GB and potentially other aphids

Assessment of disinfectants in explosive destruction system for biological agent destruction : LDRD final report FY04.

Treatment systems that can neutralize biological agents are needed to mitigate risks from novel and legacy biohazards. Tests with Bacillus thuringiensis and Bacillus steurothemophilus spores were performed in a 190-liter, 1-112 lb TNT equivalent rated Explosive Destruction System (EDS) system to evaluate its capability to treat and destroy biological agents. Five tests were conducted using three different agents to kill the spores. The EDS was operated in steam autoclave, gas fumigation and liquid decontamination modes. The first three tests used EDS as an autoclave, which uses pressurized steam to kill the spores. Autoclaving was performed at 130-140 deg C for up to 2-hours. Tests with chlorine dioxide at 750 ppm concentration for 1 hour and 10% (vol) aqueous chlorine bleach solution for 1 hour were also performed. All tests resulted in complete neutralization of the bacterial spores based on no bacterial growth in post-treatment incubations. Explosively opening a glass container to expose the bacterial spores for treatment with steam was demonstrated and could easily be done for chlorine dioxide gas or liquid bleach

Functional analysis of RXLR effectors from the New Zealand kauri dieback pathogen Phytophthora agathidicida

New Zealand kauri is an ancient, iconic, gymnosperm tree species that is under threat from a lethal dieback disease caused by the oomycete Phytophthora agathidicida. To gain insight into this pathogen, we determined whether proteinaceous effectors of P. agathidicida interact with the immune system of a model angiosperm, Nicotiana, as previously shown for Phytophthora pathogens of angiosperms. From the P. agathidicida genome, we defined and analysed a set of RXLR effectors, a class of proteins that typically have important roles in suppressing or activating the plant immune system. RXLRs were screened for their ability to activate or suppress the Nicotiana plant immune system using Agrobacterium tumefaciens transient transformation assays. Nine P. agathidicida RXLRs triggered cell death or suppressed plant immunity in Nicotiana, of which three were expressed in kauri. For the most highly expressed, P. agathidicida (Pa) RXLR24, candidate cognate immune receptors associated with cell death were identified in Nicotiana benthamiana using RNA silencing-based approaches. Our results show that RXLRs of a pathogen of gymnosperms can interact with the immune system of an angiosperm species. This study provides an important foundation for studying the molecular basis of plant–pathogen interactions in gymnosperm forest trees, including kauri

Issues and Challenges in Applications of Artificial Intelligence to Nuclear Medicine -- The Bethesda Report (AI Summit 2022)

The SNMMI Artificial Intelligence (SNMMI-AI) Summit, organized by the SNMMI AI Task Force, took place in Bethesda, MD on March 21-22, 2022. It brought together various community members and stakeholders from academia, healthcare, industry, patient representatives, and government (NIH, FDA), and considered various key themes to envision and facilitate a bright future for routine, trustworthy use of AI in nuclear medicine. In what follows, essential issues, challenges, controversies and findings emphasized in the meeting are summarized

Highly electron deficient diketopyrrolopyrroles

The synthesis, spectroelectrochemical and structural characteristics of highly electron-accepting diketopyrrrolopyrrole (DPP) molecules with adjoining pyridinium rings is reported, along with an assessment of their toxicity, which is apparently low. The compounds show reversible electrochemistry and in one subfamily a massive increase in molar extinction coefficient upon electrochemical reduction

Commercial production of Florida pompano (Trachinotus carolinus) larvae at low salinity induces variable changes in whole-larvae microbial diversity, gene expression, and gill histopathology

IntroductionSalinity presents economic and technical challenges in land-based recirculating aquaculture systems (RAS) in the U.S. warm water marine finfish aquaculture industry. Many studies have shown euryhaline fish reared at salinities closer to their iso-osmotic salinity can yield enhanced production performance as well as potential reduced costs to farms. However, there is potential for osmotic stress in fish larvae to negatively impact larvae microbiome and innate immune system. Florida pompano (Trachinotus carolinus) is a popular sportfish has been targeted for land-based RAS due to its impressive market value and euryhaline capacity. This study investigated the impacts of rearing Florida pompano larvae at salinities closer to their iso-osmotic salinity.Materials and methodsLarvae were cultured at 10, 20, and 30 ppt in triplicates, and larvae samples were collected for histopathology, microbiome, and whole transcriptomics analysis every three days from hatching until the time of weaning (24 days post hatch [DPH]). Water samples were also taken for microbiome analysis on every other larval sampling day. DiscussionThese changes were driven more by metamorphosis, causing an increase in expression of antioxidant genes (cat, gss, gsto1, and scara3) than by the presence of potentially pathogenic genera, which failed to induce an immune response (low or unchanged expression of downstream elements of the NOD1 or TLR5 pathways). These findings provide baseline information on Florida pompano low salinity tolerance in larviculture during early developmental stages. In addition, we have shown minimal effects on the immune system at salinities as low as 10 ppt. This work has important implications for larval health management and can be used to refine and direct future research regarding improving commercial production of warm water marine specie

Discovery of FERM domain protein-protein interaction inhibitors for MSN and CD44 as a potential therapeutic approach for Alzheimer\u27s disease.

Proteomic studies have identified moesin (MSN), a protein containing a four-point-one, ezrin, radixin, moesin (FERM) domain, and the receptor CD44 as hub proteins found within a coexpression module strongly linked to Alzheimer\u27s disease (AD) traits and microglia. These proteins are more abundant in Alzheimer\u27s patient brains, and their levels are positively correlated with cognitive decline, amyloid plaque deposition, and neurofibrillary tangle burden. The MSN FERM domain interacts with the phospholipid phosphatidylinositol 4,5-bisphosphate (PI