The Proteasomal Deubiquitinating Enzyme PSMD14 Regulates Macroautophagy by Controlling Golgi-to-ER Retrograde Transport

Ubiquitination regulates several biological processes, however the role of specific members of the ubiquitinome on intracellular membrane trafficking is not yet fully understood. Here, we search for ubiquitin-related genes implicated in protein membrane trafficking performing a High-Content siRNA Screening including 1187 genes of the human “ubiquitinome” using amyloid precursor protein (APP) as a reporter. We identified the deubiquitinating enzyme PSMD14, a subunit of the 19S regulatory particle of the proteasome, specific for K63-Ub chains in cells, as a novel regulator of Golgi-to-endoplasmic reticulum (ER) retrograde transport. Silencing or pharmacological inhibition of PSMD14 with Capzimin (CZM) caused a robust increase in APP levels at the Golgi apparatus and the swelling of this organelle. We showed that this phenotype is the result of rapid inhibition of Golgi-to-ER retrograde transport, a pathway implicated in the early steps of the autophagosomal formation. Indeed, we observed that inhibition of PSMD14 with CZM acts as a potent blocker of macroautophagy by a mechanism related to the retention of Atg9A and Rab1A at the Golgi apparatus. As pharmacological inhibition of the proteolytic core of the 20S proteasome did not recapitulate these effects, we concluded that PSMD14, and the K63-Ub chains, act as a crucial regulatory factor for macroautophagy by controlling Golgi-to-ER retrograde transport

Measuring the implementation of a group-based Lifestyle-integrated Functional Exercise (Mi-LiFE) intervention delivered in primary care for older adults aged 75 years or older: a pilot feasibility study protocol

Background Declines in function and quality of life, and an increased risk of cardiovascular events, falls, and fractures occur with aging and may be amenable to exercise intervention. Primary care is an ideal setting for identifying older adults in need of exercise intervention. However, a cost-effective, generalizable model of chronic disease management using exercise in a real-world setting remains elusive. Our objective is to measure the feasibility, potential effectiveness, and implementation of an evidence-based Lifestyle-integrated Functional strength and balance Exercise (LiFE) intervention adapted as a group-based format (Mi-LiFE) for primary care to promote increased physical activity levels in older adults aged 75 years or older. We hypothesize that the intervention will be feasible without modification if ≥30 individuals are recruited over 6 months, ≥75 % of our sample is retained, and ≥50 % of our sample complete exercises ≥3 days per week. Methods/design A pre-post pilot study design will be used to evaluate feasibility, potential effectiveness, and implementation outcomes over a 6-month period in physically inactive older adults ≥75 years recruited from a local family health team practice. The reach, effectiveness, adoption, implementation, and maintenance (RE-AIM) framework will be applied to evaluate the public health effects of the intervention including outcomes both at the individual and organizational levels. A physical therapist will teach participants how to integrate strength and balance activities into their daily lives over one individual and four group-based sessions, and two phone calls. Assessments will be completed at baseline and 6 months. Feasibility outcomes include recruitment over 6 months, retention at follow-up, and adherence measured by activity diaries. Change in patient-centered and implementation outcomes that will be evaluated include physical activity levels using accelerometers and International Physical Activity Questionnaire, physical performance using short physical performance battery, quality of life using EQ5D questionnaire, falls and harms using daily calendar diaries and self-report, fidelity using descriptive feedback, barriers and facilitators to implementation using thematic content analysis, and process outcomes. Discussion The feasibility and implementation of the Mi-LiFE intervention in primary care for older adults will be evaluated, as well as the effects of the intervention on secondary outcomes. If the intervention appears feasible, we will use the resultant information to design a larger trial.The Chronic Disease Prevention Initiative seed grant (https://uwaterloo.ca/propel/waterloo-chronic-disease-prevention-initiative) from the Propel Centre for Population Health Impact at the University of Waterloo funded the Mi-LiFE study

Association between childhood trauma and mental health disorders in adolescents during the second pandemic wave of COVID-19, Chiclayo-Peru

"Introduction: The COVID-19 pandemic has significantly affected mental health, with children and adolescents being particularly vulnerable. Evidence on the association between childhood trauma and mental health outcomes in schoolchildren during the pandemic is limited. This study aimed to evaluate this relationship in Chiclayo city, northern Peru, during the second wave of COVID-19. Methods: A cross-sectional secondary data study was conducted, measuring childhood trauma using the Marshall’s Trauma Scale, depressive symptomatology (PHQ-9), and anxiety symptomatology (GAD-7). Additional variables assessed were alcohol use (AUDIT), resilience (abbreviated CD-RISC), and socio-educational data. Prevalence ratios were estimated using generalized linear models. Results: Among 456 participants, 88.2% were female, with a mean age of 14.5 years (SD: 1.33). Depressive symptomatology prevalence was 76.3% (95%CI: 72.14– 80.15) and increased by 23% in schoolchildren with childhood trauma (PR: 1.23; 95%CI: 1.10–1.37). Factors positively associated with depressive symptomatology included increasing age, seeking mental health help during the pandemic, and severe family dysfunction. Anxiety symptomatology prevalence was 62.3% (95%CI: 57.65–66.75) and increased by 55% in schoolchildren with childhood trauma (PR: 1.55; 95%CI: 1.31–1.85). Anxiety symptomatology was positively associated with mild, moderate, and severe family dysfunction. Conclusion: Schoolchildren exposed to childhood trauma are at increased risk for depressive and anxiety symptoms. Monitoring the impact of the COVID-19 pandemic on adolescent mental health is vital. These findings can assist schools in establishing effective measures to prevent mental health outcomes

Severe childhood malaria syndromes defined by plasma proteome profiles

BACKGROUND Cerebral malaria (CM) and severe malarial anemia (SMA) are the most serious life-threatening clinical syndromes of Plasmodium falciparum infection in childhood. Therefore it is important to understand the pathology underlying the development of CM and SMA, as opposed to uncomplicated malaria (UM). Different host responses to infection are likely to be reflected in plasma proteome-patterns that associate with clinical status and therefore provide indicators of the pathogenesis of these syndromes. METHODS AND FINDINGS Plasma and comprehensive clinical data for discovery and validation cohorts were obtained as part of a prospective case-control study of severe childhood malaria at the main tertiary hospital of the city of Ibadan, an urban and densely populated holoendemic malaria area in Nigeria. A total of 946 children participated in this study. Plasma was subjected to high-throughput proteomic profiling. Statistical pattern-recognition methods were used to find proteome-patterns that defined disease groups. Plasma proteome-patterns accurately distinguished children with CM and with SMA from those with UM, and from healthy or severely ill malaria-negative children. CONCLUSIONS We report that an accurate definition of the major childhood malaria syndromes can be achieved using plasma proteome-patterns. Our proteomic data can be exploited to understand the pathogenesis of the different childhood severe malaria syndromes

Structural basis for the RING catalyzed synthesis of K63 linked ubiquitin chains

This work was supported by grants from Cancer Research UK (C434/A13067), the Wellcome Trust (098391/Z/12/Z) and Biotechnology and Biological Sciences Research Council (BB/J016004/1).The RING E3 ligase catalysed formation of lysine 63 linked ubiquitin chains by the Ube2V2–Ubc13 E2 complex is required for many important biological processes. Here we report the structure of the RING domain dimer of rat RNF4 in complex with a human Ubc13~Ub conjugate and Ube2V2. The structure has captured Ube2V2 bound to the acceptor (priming) ubiquitin with Lys63 in a position that could lead to attack on the linkage between the donor (second) ubiquitin and Ubc13 that is held in the active “folded back” conformation by the RING domain of RNF4. The interfaces identified in the structure were verified by in vitro ubiquitination assays of site directed mutants. This represents the first view of the synthesis of Lys63 linked ubiquitin chains in which both substrate ubiquitin and ubiquitin-loaded E2 are juxtaposed to allow E3 ligase mediated catalysis.PostprintPeer reviewe

Structural insight into SUMO chain recognition and manipulation by the ubiquitin ligase RNF4

The small ubiquitin-like modifier (SUMO) can form polymeric chains that are important signals in cellular processes such as meiosis, genome maintenance and stress response. The SUMO-targeted ubiquitin ligase RNF4 engages with SUMO chains on linked substrates and catalyses their ubiquitination, which targets substrates for proteasomal degradation. Here we use a segmental labelling approach combined with solution nuclear magnetic resonance (NMR) spectroscopy and biochemical characterization to reveal how RNF4 manipulates the conformation of the SUMO chain, thereby facilitating optimal delivery of the distal SUMO domain for ubiquitin transfer