A Lipid Binding Structure and Functional Analysis of Human ARV1

Metabolic Syndrome (MetS) is a combination of risk factors that can over time increase the probability of developing diseases, including cardiovascular disease, type 2 diabetes, non-alcoholic fatty liver disease (NAFLD), and non-alcoholic steatohepatitis (NASH). Acyl-coenzyme-A: cholesterol O-acyl transferase related enzyme required for viability-1, abbreviated as Arv1, is an evolutionarily conserved putative lipid binding protein. Several studies have implicated hArv1 as a critical regulator of lipid transport and trafficking. Recent work using an Arv1 knock out (KO) mouse model have established a clear link between Arv1 function and the progression of MetS and NAFLD/NASH [unpublished data] [1]. Overall, studies show that KO animals exhibit a reduction in body weight, have less blood circulating cholesterol, are more glucose tolerant and insulin sensitive, and show severely reduced signs of NASH. Little is known about whether Arv1 binds lipids directly and if it is involved in their transport in any way. Here, we explored whether Arv1 could bind lipid, and if so what was its lipid specificity for binding. Moreover, we undertook a structure/function approach to define the critical residues within the hArv1 homology domain (AHD) required for function. Homogeneous time resolved fluorescence (HTRF) assays were used to assess the interactions between Arv1 and specific phospholipids. We found that hArv1 directly binds to phosphatidylglycerol (PG), phosphatidic acid (PA), cardiolipin (CL) and hosphatidylserine (PS) with decreasing affinity. Using site directed mutagenesis, we identified specific residues that are required for AHD lipid binding. Overall, we have verified that the AHD of Arv1 does have lipid binding activity. Moreover, we have defined critical residues within the AHD that are required for this binding. Understanding the molecular basis for Arv1 lipid binding will further our understanding of how hArv1 may be contributing to the initiation and/or progression of MetS related diseases

The Effect of Cadmium Exposure on Repeat Swimming Performance and Recovery in Rainbow Trout (\u3cem\u3eOncorhynchus mykiss\u3c/em\u3e), Brown Trout (\u3cem\u3eSalmo trutta\u3c/em\u3e) and Lake Whitefish (\u3cem\u3eCoregonus clupeaformis\u3c/em\u3e)

Swim performance provides a measure of the integrated metabolic costs of sub-lethal exposure to stressors, including Cd. While the impacts to sustained swimming performance in Cd exposed fish have already been characterised, effects to repeat swimming ability have not. This thesis identifies the effects of sub-lethal waterborne Cd exposure on ionoregulatory function, repeat swimming ability, anaerobic metabolism and stress response in rainbow trout (Oncorhynchus mykiss), brown trout (Salmo trutta) and lake whitefish (Coregonus clupeaformis). Repeat swim trials included an initial swim to 85% of the Ucrit of control fish and a recovery period of varying duration, followed by a second, exhaustive, swim trial. Fish were terminally sampled prior to and directly following each of the two swim challenges so as to evaluate fluctuations in metabolic (glycogen, lactate, ATP) and stress (cortisol) parameters as a result of exercise and Cd exposure. All exposures were performed in duplicate with an exposure concentration of 18 nM Cd in moderately hard water (120 mg CaCO3 L-1) and a control group. Repeat swimming ability was assessed in brown trout and lake whitefish over a 30 day period. Cd exposure resulted in 31% and 38% decreases in secondary swimming ability of each species, with the greatest decreases observed after one week of exposure. This reduction in swimming ability was associated with ionoregulatory disruption and reduced resting ATP stores in the white muscle. As a result, a second study was performed in order to identify the role of the recovery period. Recovery ability was evaluated in rainbow trout following 6 d exposure to 0 or 18 nM Cd. Three recovery periods were employed; 0.5, 1.5 and 6 h so as to identify the effect of Cd exposure on the recovery of metabolic parameters. As anticipated, Cd exposed fish had decreased swimming ability when given a short, 0.5h recovery period. However, a 1.5 hour recovery period resulted in significantly increased swimming performance in Cd exposed fish compared with controls. Improved swimming ability in Cd exposed fish corresponded to increased rates of recovery of muscle and liver glycogen and ATP and reductions in lactate, compared with control fish

An Erg11 lanosterol 14-α-demethylase-Arv1 complex is required for Candida albicans virulence.

Azole resistant fungal infections remain a health problem for the immune compromised. Current therapies are limited due to rises in new resistance mechanisms. Therefore, it is important to identify new drug targets for drug discovery and novel therapeutics. Arv1 (are1 are2 required for viability 1) function is highly conserved between multiple pathogenic fungal species. Candida albicans (C. albicans) cells lacking CaArv1 are azole hypersusceptible and lack virulence. Saccharomyces cerevisiae (S. cerevisiae) Scarv1 cells are also azole hypersusceptible, a phenotype reversed by expression of CaArv1, indicating conservation in the molecular mechanism for azole susceptibility. To define the relationship between Arv1 function and azole susceptibility, we undertook a structure/function analysis of ScArv1. We identified several conserved amino acids within the ScArv1 homology domain (ScAhd) required for maintaining normal azole susceptibility. Erg11 lanosterol 14-α-demethylase is the rate-limiting enzyme in sterol biosynthesis and is the direct target of azole antifungals, so we used our ScArv1 mutants in order to explore the relationship between ScArv1 and ScErg11. Specific ScArv1 mutants ectopically expressed from a low copy plasmid were unable to restore normal azole susceptibility to Scarv1 cells and had reduced Erg11 protein levels. Erg11 protein stability depended on its ability to form a heterodimeric complex with Arv1. Complex formation was required for maintaining normal azole susceptibility. Scarv1 cells expressing orthologous CaArv1 mutants also had reduced CaErg11 levels, were unable to form a CaArv1-CaErg11 complex, and were azole hypersusceptible. Scarv1 cells expressing CaArv1 mutants unable to interact with CaErg11 could not sustain proper levels of the azole resistant CaErg11Y132F F145L protein. Caarv1/Caarv1 cells expressing CaArv1 mutants unable to interact with CaErg11 were found to lack virulence using a disseminated candidiasis mouse model. Expressing CaErg11Y132F F145L did not reverse the lack of virulence. We hypothesize that the role of Arv1 in Erg11-dependent azole resistance is to stabilize Erg11 protein level. Arv1 inhibition may represent an avenue for treating azole resistance

Evaluation of a health promoting schools program in a school board in Nova Scotia, Canada.

A Health promoting schools (HPS) approach aims to make schools a healthy place through a holistic approach that promotes a supportive 'school ethos' and emphasizes improvements in physical, social, and emotional well-being and educational outcomes. A HPS initiative in rural Nova Scotia (Canada) provided an opportunity for a population-level natural experiment. This study investigated student well-being and health behaviours between schools with and without HPS implementation and schools with high and low school ethos scores. Student well-being, nutrition, and physical activity were examined in a cross-sectional survey of elementary students in Nova Scotia, Canada in 2014. Multiple regression was used to assess the relationship with student well-being using the Quality of Life in School (QoLS) instrument and health behaviours. The main exposure was attending one of the 10 HPS schools; secondary exposure was the school ethos score. The overall QoLS score and its subdomain scores in the adjusted models were higher in students attending HPS schools compared to those in non-HPS schools, but the differences were not statistically significant and the effect sizes were small. Students in schools that scored high on school ethos score had higher scores for the QoLS and its subdomains, but the difference was only significant for the teacher-student relationship domain. Although this study did not find significant differences between HPS and non-HPS schools, our results highlight the complexity of evaluating HPS effects in the real world. The findings suggest a potential role of a supportive school ethos for student well-being in school

Neptunism and transformism:Robert Jameson and other evolutionary theorists in early nineteenth-century Scotland

This paper sheds new light on the prevalence of evolutionary ideas in Scotland in the early nineteenth century and establish what connections existed between the espousal of evolutionary theories and adherence to the directional history of the earth proposed by Abraham Gottlob Werner and his Scottish disciples. A possible connection between Wernerian geology and theories of the transmutation of species in Edinburgh in the period when Charles Darwin was a medical student in the city was suggested in an important 1991 paper by James Secord. This study aims to deepen our knowledge of this important episode in the history of evolutionary ideas and explore the relationship between these geological and evolutionary discourses. To do this it focuses on the circle of natural historians around Robert Jameson, Wernerian geologist and professor of natural history at the University of Edinburgh from 1804 to 1854. From the evidence gathered here there emerges a clear confirmation that the Wernerian model of geohistory facilitated the acceptance of evolutionary explanations of the history of life in early nineteenth-century Scotland. As Edinburgh was at this time the most important center of medical education in the English-speaking world, this almost certainly influenced the reception and development of evolutionary ideas in the decades that followed.</p

Integrated knowledge translation in population health intervention research: a case study of implementation and outcomes from a school-based project.

BACKGROUND: Integrated knowledge translation (IKT) is encouraged in population health intervention research (PHIR) to ensure the co-production of policy-relevant research, yet there is little published literature that reports its implementation and outcomes. The purpose of this study was to describe and evaluate the IKT approach used in a school-based PHIR project to understand how the research informed policy and practice and identify what influenced the IKT process. METHODS: A case study approach was used to provide an in-depth description of the IKT process and understand the co-production and application of research evidence. Data were collected through document review, a survey with all elementary school principals in the school board (n = 18) following dissemination of School Reports and interviews with the IKT research team (including two researchers and three knowledge users). RESULTS: Approximately half of the principals reported reading their School Report (52%) and almost all of these principals attributed the partial or full adoption, or implementation, of a new practice as a result of using the information (89%). Key themes related to the IKT process emerged across the interviews, including supportive relationships, role clarity, competing priorities and the complexities of population health interventions. CONCLUSIONS: The findings suggest that, while IKT can support policy and practice, it can be challenging to maintain engagement due to differing priorities and role ambiguity. Additional recognition, investment and research would enable better implementation of the approach, thereby bridging the gap between research, policy and practice

Patient, caregiver and other knowledge user engagement in consensus-building healthcare initiatives: a scoping review protocol

Introduction Patient engagement and integrated knowledge translation (iKT) processes improve health outcomes and care experiences through meaningful partnerships in consensus-building initiatives and research. Consensus-building is essential for engaging a diverse group of experienced knowledge users in co-developing and supporting a solution where none readily exists or is less optimal. Patients and caregivers provide invaluable insights for building consensus in decision-making around healthcare, policy and research. However, despite emerging evidence, patient engagement remains sparse within consensus-building initiatives. Specifically, our research has identified a lack of opportunity for youth living with chronic health conditions and their caregivers to participate in developing consensus on indicators/benchmarks for transition into adult care. To bridge this gap and inform our consensus-building approach with youth/caregivers, this scoping review will synthesise the extent of the literature on patient and other knowledge user engagement in consensus-building healthcare initiatives. Methods and analysis Following the scoping review methodology from Joanna Briggs Institute, published literature will be searched in MEDLINE, EMBASE, CINAHL and PsycINFO databases from inception to July 2023. Grey literature will be hand-searched. Two independent reviewers will determine the eligibility of articles in a two-stage process, with disagreements resolved by a third reviewer. Included studies must be consensus-building studies within the healthcare context that involve patient engagement strategies. Data from eligible studies will be extracted and charted on a standardised form. Abstracted data will be analysed quantitatively and descriptively, according to specific consensus methodologies, and patient engagement models and/or strategies. Ethics and dissemination Ethics approval is not required for this scoping review protocol. The review process and findings will be shared with and informed by relevant knowledge users. Dissemination of findings will also include peer-reviewed publications and conference presentations. The results will offer new insights for supporting patient engagement in consensus-building healthcare initiatives. Protocol registration https://osf.io/beqj

AI is a viable alternative to high throughput screening: a 318-target study

: High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery