Multiple Autism-Linked Genes Mediate Synapse Elimination via Proteasomal Degradation of a Synaptic Scaffold PSD-95

SummaryThe activity-dependent transcription factor myocyte enhancer factor 2 (MEF2) induces excitatory synapse elimination in mouse neurons, which requires fragile X mental retardation protein (FMRP), an RNA-binding protein implicated in human cognitive dysfunction and autism. We report here that protocadherin 10 (Pcdh10), an autism-spectrum disorders gene, is necessary for this process. MEF2 and FMRP cooperatively regulate the expression of Pcdh10. Upon MEF2 activation, PSD-95 is ubiquitinated by the ubiquitin E3 ligase murine double minute 2 (Mdm2) and then binds to Pcdh10, which links it to the proteasome for degradation. Blockade of the Pcdh10-proteasome interaction inhibits MEF2-induced PSD-95 degradation and synapse elimination. In FMRP-lacking neurons, elevated protein levels of eukaryotic translation elongation factor 1 α (EF1α), an Mdm2-interacting protein and FMRP target mRNA, sequester Mdm2 and prevent MEF2-induced PSD-95 ubiquitination and synapse elimination. Together, our findings reveal roles for multiple autism-linked genes in activity-dependent synapse elimination

Dual targeting of CCR2 and CX3CR1 in an arterial injury model of vascular inflammation

<p>Abstract</p> <p>Objectives</p> <p>The chemokine receptors CCR2 and CX3CR1 are important in the development of coronary artery disease. The purpose of this study is to analyze the effect of a novel CCR2 inhibitor in conjunction with CX3CR1 deletion on vascular inflammation.</p> <p>Methods</p> <p>The novel CCR2 antagonist MRL-677 was characterized using an in vivo model of monocyte migration. To determine the relative roles of CCR2 and CX3CR1 in vascular remodeling, normal or CX3CR1 deficient mice were treated with MRL-677. After 14 days, the level of intimal hyperplasia in the artery was visualized by paraffin sectioning and histology of the hind limbs.</p> <p>Results</p> <p>MRL-677 is a CCR2 antagonist that is effective in blocking macrophage trafficking in a peritoneal thioglycollate model. Intimal hyperplasia resulting from vascular injury was also assessed in mice. Based on the whole-blood potency of MRL-677, sufficient drug levels were maintained for the entire 14 day experimental period to afford good coverage of mCCR2 with MRL-677. Blocking CCR2 with MRL-677 resulted in a 56% decrease in the vascular injury response (n = 9, p < 0.05) in normal animals. Mice in which both CCR2 and CX3CR1 pathways were targeted (CX3CR1 KO mice given MRL-677) had an 88% decrease in the injury response (n = 6, p = 0.009).</p> <p>Conclusion</p> <p>In this study we have shown that blocking CCR2 with a low molecular weight antagonist ameliorates the inflammatory response to vascular injury. The protective effect of CCR2 blockade is increased in the presence of CX3CR1 deficiency suggesting that CX3CR1 and CCR2 have non-redundant functions in the progression of vascular inflammation.</p

Editor's Choice - Carotid Stenosis Treatment : Variation in International Practice Patterns

Objectives: The aim was to determine current practice for the treatment of carotid stenosis among 12 countries participating in the International Consortium of Vascular Registries (ICVR). Methods: Data from the United States Vascular Quality Initiative (VQI) and the Vascunet registry collaboration (including 10 registries in Europe and Australasia) were used. Variation in treatment modality of asymptomatic versus symptomatic patients was analysed between countries and among centres within each country. Results: Among 58,607 procedures, octogenarians represented 18% of all patients, ranging from 8% (Hungary) to 22% (New Zealand and Australia). Women represented 36%, ranging from 29% (Switzerland) to 40% (USA). The proportion of carotid artery stenting (CAS) among asymptomatic patients ranged from 0% (Finland) to 26% (Sweden) and among symptomatic patients from 0% (Denmark) to 19% (USA). Variation among centres within countries for CAS was highest in the United States and Australia (from 0% to 80%). The overall proportion of asymptomatic patients was 48%, but varied from 0% (Denmark) to 73% (Italy). There was also substantial centre level variation within each country in the proportion of asymptomatic patients, most pronounced in Australia (0-72%), Hungary (5-55%), and the United States (0-100%). Countries with fee for service reimbursement had higher rates of treatment in asymptomatic patients than countries with population based reimbursement (OR 5.8, 95% CI 4.4-7.7). Conclusions: Despite evidence about treatment options for carotid artery disease, the proportion of asymptomatic patients, treatment modality, and the proportion of women and octogenarians vary considerably among and within countries. There was a significant association of treating more asymptomatic patients in countries with fee for service reimbursement. The findings reflect the inconsistency of the existing guidelines and a need for cooperation among guideline committees all over the world. (C) 2017 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.Peer reviewe

Extracellular vesicle features are associated with COVID-19 severity

COVID-19 is heterogeneous; therefore, it is crucial to identify early biomarkers for adverse outcomes. Extracellular vesicles (EV) are involved in the pathophysiology of COVID-19 and have both negative and positive effects. The objective of this study was to identify the potential role of EV in the prognostic stratification of COVID-19 patients. A total of 146 patients with severe or critical COVID-19 were enrolled. Demographic and comorbidity characteristics were collected, together with routine haematology, blood chemistry and lymphocyte subpopulation data. Flow cytometric characterization of the dimensional and antigenic properties of COVID-19 patients' plasma EVs was conducted. Elastic net logistic regression with cross-validation was employed to identify the best model for classifying critically ill patients. Features of smaller EVs (i.e. the fraction of EVs smaller than 200 nm expressing either cluster of differentiation [CD] 31, CD 140b or CD 42b), albuminemia and the percentage of monocytes expressing human leukocyte antigen DR (HLA-DR) were associated with a better outcome. Conversely, the proportion of larger EVs expressing N-cadherin, CD 34, CD 56, CD31 or CD 45, interleukin 6, red cell width distribution (RDW), N-terminal pro-brain natriuretic peptide (NT-proBNP), age, procalcitonin, Charlson Comorbidity Index and pro-adrenomedullin were associated with disease severity. Therefore, the simultaneous assessment of EV dimensions and their antigenic properties complements laboratory workup and helps in patient stratification

Bright Metal-Poor Stars from the Hamburg/ESO Survey. I. Selection and Follow-up Observations from 329 Fields

We present a sample of 1777 bright (9<B<14) metal-poor candidates selected from the Hamburg/ESO Survey (HES). Despite saturation effects present in the red portion of the HES objective-prism spectra, the data were recoverable and quantitative selection criteria could be applied to select the sample. Analyses of medium-resolution (~2 A) follow-up spectroscopy of the entire sample, obtained with several 2 to 4 m class telescopes, yielded 145 new metal-poor stars with metallicity [Fe/H]<-2.0, of which 79 have [Fe/H]<-2.5, and 17 have [Fe/H]<-3.0. We also obtained C/Fe estimates for all these stars. From this, we find a frequency of C-enhanced ([C/Fe]>1.0) metal-poor ([Fe/H]<-2.0) giants of 9% +- 2%, which is lower than previously reported. However, the frequency raises to similar (>20%) and higher values with increasing distance from the Galactic plane. Although the numbers of stars at low metallicity are falling rapidly at the lowest metallicities, there is evidence that the fraction of carbon-enhanced metal-poor stars is increasing rapidly as a function of declining metallicity. For ~60 objects, high-resolution data have already been obtained; one of these, HE 1327-2326, is the new record holder for the most iron-deficient star known.Comment: 29 pages (emulateapj), accepted for publication in Ap

Peri-Operative Management of Patients Undergoing Fenestrated-Branched Endovascular Repair for Juxtarenal, Pararenal and Thoracoabdominal Aortic Aneurysms: Preventing, Recognizing and Treating Complications to Improve Clinical Outcomes

The advent and refinement of complex endovascular techniques in the last two decades has revolutionized the field of vascular surgery. This has allowed an effective minimally invasive treatment of extensive disease involving the pararenal and the thoracoabdominal aorta. Fenestrated-branched EVAR (F/BEVAR) now represents a feasible technical solution to address these complex diseases, moving the proximal sealing zone above the renal-visceral vessels take-off and preserving their patency. The aim of this paper was to provide a narrative review on the peri-operative management of patients undergoing F/BEVAR procedures for juxtarenal abdominal aortic aneurysm (JAAA), pararenal abdominal aortic aneurysm (PRAA) or thoracoabdominal aortic aneurism (TAAA). It will focus on how to prevent, diagnose, and manage the complications ensuing from these complex interventions, in order to improve clinical outcomes. Indeed, F/BEVAR remains a technically, physiologically, and mentally demanding procedure. Intraoperative adverse events often require prolonged or additional procedures and complications may significantly impact a patient’s quality of life, health status, and overall cost of care. The presence of standardized preoperative, perioperative, and postoperative pathways of care, together with surgeons and teams with significant experience in aortic surgery, should be considered as crucial points to improve clinical outcomes. Aggressive prevention, prompt diagnosis and timely rescue of any major adverse events following the procedure remain paramount clinical needs

Deriving and critiquing an empirically-based framework for pharmaceutical ethics.

Background: The pharmaceutical industry has been responsible for major medical advances, but the industry has also been heavily criticized. Such criticisms, and associated regulatory responses, are no doubt often warranted, but do not provide a framework for those who wish to reason systematically about the moral dimensions of drug development. We set out to develop such a framework using Beauchamp and Childress’s “four principles” as organizing categories. Methods: We conducted a qualitative interview study of people working in the “medical affairs” departments of pharmaceutical companies to determine: (1) whether our data could meaningfully be organized under the headings of “autonomy,” “beneficence,” “nonmaleficence,” and “justice”; (2) how principles might be expressed in this particular commercial setting; and (3) if these principles are expressed, whether and how competing principles are balanced. We then critiqued these findings using existing normative theory. Results: Our interviews demonstrated that three of Beauchamp and Childress’ four principles were salient to our participants: beneficence, non-maleficence, and justice. Within each of these principles, participants had two broad ethical orientations: an altruistic public focus (“other-ness”) and a commitment to their companies (“firm-ness”). Our participants also demonstrated efforts to balance these principles and highlighted the importance of phronesis (or practical wisdom) in balancing and enacting principles. Notably, however, our participants did not spontaneously emphasize the importance of autonomy. Conclusions: It is possible to use qualitative empirical research, together with normative analysis, to derive a framework for pharmaceutical ethics. We suggest that our framework would be useful for those who wish to reason ethically within, or in collaboration with, the pharmaceutical industry. Keywords: Empirical ethics, principle-based ethics, pharmaceutical industry, pharmaceutical ethics, qualitative researchNHMRC Career Development Fellowship APP106356

Proteasome Activator Enhances Survival of Huntington's Disease Neuronal Model Cells

In patients with Huntington's disease (HD), the proteolytic activity of the ubiquitin proteasome system (UPS) is reduced in the brain and other tissues. The pathological hallmark of HD is the intraneuronal nuclear protein aggregates of mutant huntingtin. We determined how to enhance UPS function and influence catalytic protein degradation and cell survival in HD. Proteasome activators involved in either the ubiquitinated or the non-ubiquitinated proteolysis were overexpressed in HD patients' skin fibroblasts or mutant huntingtin-expressing striatal neurons. Following compromise of the UPS, overexpression of the proteasome activator subunit PA28γ, but not subunit S5a, recovered proteasome function in the HD cells. PA28γ also improved cell viability in mutant huntingtin-expressing striatal neurons exposed to pathological stressors, such as the excitotoxin quinolinic acid and the reversible proteasome inhibitor MG132. These results demonstrate the specific functional enhancements of the UPS that can provide neuroprotection in HD cells