NCAM180 Regulates Ric8A Membrane Localization and Potentiates β-Adrenergic Response

Cooperation between receptors allows integrated intracellular signaling leading to appropriate physiological responses. The Neural Cell Adhesion Molecule (NCAM) has three main isoforms of 120, 140 and 180 kDa, with adhesive and signaling properties, but their respective functions remains to be fully identified. Here we show that the human NCAM180 intracellular domain is a novel interactor of the human guanosine exchange factor (GEF) Ric8A using the yeast two hybrid system and immunoprecipitation. Furthermore, NCAM, Ric8A and Gαs form a tripartite complex. Colocalization experiments by confocal microscopy revealed that human NCAM180 specifically induces the recruitment of Ric8A to the membrane. In addition, using an in vitro recombinant system, and in vivo by comparing NCAM knock-out mouse brain to NCAM heterozygous and wild type brains, we show that NCAM expression dose dependently regulates Ric8A redistribution in detergent resistent membrane microdomains (DRM). Previous studies have demonstrated essential roles for Ric8 in Gα protein activity at G protein coupled receptors (GPCR), during neurotransmitter release and for asymmetric cell division. We observed that inhibition of Ric8A by siRNA or its overexpression, decreases or increases respectively, cAMP production following β-adrenergic receptor stimulation. Furthermore, in human HEK293T recombinant cells, NCAM180 potentiates the Gαs coupled β-adrenergic receptor response, in a Ric8A dependent manner, whereas NCAM120 or NCAM140 do not. Finally, in mouse hippocampal neurons expressing endogenously NCAM, NCAM is required for the agonist isoproterenol to induce cAMP production, and this requirement depends on Ric8A. These data illustrate a functional crosstalk between a GPCR and an IgCAM in the nervous system

18F-Fluciclovine PET/CT performance in biochemical recurrence of prostate cancer: a systematic review

Background A systematic literature review of the performance of 18Fluorine-fluciclovine PET/CT for imaging of men with recurrent prostate cancer was performed. Methods Scientific literature databases (MEDLINE, ScienceDirect and Cochrane Libraries) were searched systematically during Oct 2020 using PRISMA criteria. No limit was put on the date of publication. Prospective studies reporting a patient-level 18F-fluciclovine detection rate (DR) from ≥25 patients with recurrent prostate cancer were sought. Proceedings of relevant meetings held from 2018 through Oct 2020 were searched for abstracts meeting criteria. Results Searches identified 321 unique articles. In total, nine articles (six papers and three conference abstracts), comprising a total of 850 patients met inclusion criteria. Most studies (n = 6) relied on ASTRO-Phoenix Criteria, EAU-ESTRO-SIOG, and/or ASTRO-AUA guidelines to identify patients with biochemical recurrence. Patients’ PSA levels ranged from 0.02–301.7 ng/mL (median level per study, 0.34–4.10 ng/mL [n = 8]). Approximately 64% of patients had undergone prostatectomy, but three studies focused solely on post-prostatectomy patients. Adherence to imaging protocol guidelines was heterogeneous, with variance seen in administered activity, uptake and scan times. Overall patient-level DR varied between studies from 26% to 83%, with 78% of studies reporting a DR > 50%. DR was proportional to PSA, but even at PSA < 0.5 ng/mL DR of up to 53% were reported. Prostate/bed DR (n = 7) ranged from 18% to 78% and extra-prostatic rates (n = 6) from 8% to 72%. Pelvic node and bone lesion DR ranged from 8% to 47% and 0% to 26%, respectively (n = 5). 18F-Fluciclovine PET/CT was shown to impact patient management and outcomes. Two studies reported 59–63% of patients to have a management change post-scan. A further study showed significant increase in failure-free survival following 18F-fluciclovine-guided compared with conventional imaging-guided radiotherapy planning. Conclusions 18F-Fluciclovine PET/CT shows good performance in patients with recurrent prostate cancer leading to measurable clinical benefits. Careful adherence to recommended imaging protocols may help optimize DR

Community Willingness to Participate in a Dengue Study in Aceh Province, Indonesia

Background: Dengue virus infection is the most rapidly spreading vector-borne disease in the world. Essential research on dengue virus transmission and its prevention requires community participation. Therefore, it is crucial to understand the factors that are associated with the willingness of communities in high prevalence areas to participate in dengue research. The aim of this study was to explore factors associated with the willingness of healthy community members in Aceh province, Indonesia, to participate in dengue research that would require phlebotomy. Methodology/Principal Findings: A community-based cross-sectional study was carried out in nine regencies and municipalities of Aceh from November 2014 to March 2015. Interviews using a set of validated questionnaires were conducted to collect data on demography, history of dengue infection, socioeconomic status, and knowledge, attitude and practice regarding dengue fever. Two-step logistic regression and Spearman's rank correlation (rs) analysis were used to assess the influence of independent variables on dependent variables. Among 535 participants, less than 20% had a good willingness to participate in the dengue study. The factors associated with good willingness to participate were being female, working as a civil servant, private employee or entrepreneur, having a high socioeconomic status and good knowledge, attitude and practice regarding dengue. Good knowledge and attitude regarding dengue were positive independent predictors of willingness to participate (OR: 2.30 [95% CI: 1.36-3.90] and 3.73 [95% CI: 2.24-6.21], respectively). Conclusion/Significance: The willingness to participate in dengue research is very low among community members in Aceh, and the two most important associated factors are knowledge and attitude regarding dengue. To increase participation rate, efforts to improve the knowledge and attitude of community members regarding dengue fever and dengue-related research is required before such studies are launched

Evaluation of appendicitis risk prediction models in adults with suspected appendicitis

Background Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis. Methods A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16–45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis). Results Some 5345 patients across 154 UK hospitals were identified, of which two‐thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut‐off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut‐off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent). Conclusion Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision‐making by identifying adults in the UK at low risk of appendicitis were identified

The Interaction between Factor H and Von Willebrand Factor

Complement factor H (fH) is a plasma protein that regulates activation of the alternative pathway, and mutations in fH are associated with a rare form of thrombotic microangiopathy (TMA), known as atypical hemolytic uremic syndrome (aHUS). A more common TMA is thrombotic thrombocytopenic purpura, which is caused by the lack of normal ADAMTS-13-mediated cleavage of von Willebrand factor (VWF). We investigated whether fH interacts with VWF and affects cleavage of VWF. We found that factor H binds to VWF in plasma, to plasma-purified VWF, and to recombinant A1 and A2 domains of VWF as detected by co-immunoprecipitation (co-IP) and surface plasmon resonance assays. Factor H enhanced ADAMTS-13-mediated cleavage of recombinant VWF-A2 as determined by quantifying the cleavage products using Western-blotting, enhanced cleavage of a commercially available fragment of VWF-A2 (FRETS-VWF73) as determined by fluorometric assay, and enhanced cleavage of ultralarge (UL) VWF under flow conditions as determined by cleavage of VWF-platelet strings attached to histamine stimulated endothelial cells. Using recombinant full-length and truncated fH molecules, we found that the presence of the C-terminal half of fH molecule is important for binding to VWF-A2 and for enhancing cleavage of the A2 domain by ADAMTS-13. We conclude that factor H binds to VWF and may modulate cleavage of VWF by ADAMTS-13