Methionine Restriction Impairs Degradation of a Protein that Aberrantly Engages the Endoplasmic Reticulum Translocon.

Proteins that persistently engage endoplasmic reticulum (ER) translocons are degraded by multiple translocon quality control (TQC) mechanisms. In Saccharomyces cerevisiae , the model translocon-associated protein Deg1 -Sec62 is subject to ER-associated degradation (ERAD) by the Hrd1 ubiquitin ligase and, to a lesser extent, proteolysis mediated by the Ste24 protease. In a recent screen, we identified nine methionine-biosynthetic genes as candidate TQC regulators. Here, we found methionine restriction impairs Hrd1-independent Deg1 -Sec62 degradation. Beyond revealing methionine as a novel regulator of TQC, our results urge caution when working with laboratory yeast strains with auxotrophic mutations, often presumed not to influence cellular processes under investigation.

Predicting college student prescription stimulant misuse: An analysis from ecological momentary assessment.

Prescription stimulant misuse (PSM) is common in young adult college students, at over 10% in the past year, and it is associated with other substance use and risk behaviors. Research focused on the real-time drivers of PSM is absent, impeding prevention and intervention. This research aimed to fill that gap by examining the relationships between affect, global stress, or academic stress and PSM via ecological momentary assessment (EMA); we also investigated baseline predictors of PSM frequency during the 21-day EMA period. Forty-one full-time college students (mean age: 20.5, 66% female) who endorsed current PSM (≥ 6 past-year episodes) participated. Participants were asked to complete EMA questions in response to 3 daily investigator-initiated prompts and after every PSM episode. Assessments were selected based on affect regulation (e.g., positive affect [PA], negative affect [NA]) and drug instrumentalization (e.g., academic stress and/or demands) theories of substance use. Mixed-effects linear models examined EMA data, and negative binomial regression analyses examined baseline predictors of PSM episode frequency. PA was higher on PSM days and increased post-PSM, whereas NA was unrelated to PSM. Although global and academic stress were largely unrelated to PSM, when the motive endorsed for PSM was "to study," pre-PSM ratings of academic demand and stress were significantly higher. Finally, a history of recreational motives (e.g., to get high) or higher levels of attention-deficit/hyperactivity disorder symptoms predicted a greater number of PSM episodes over the EMA period. The results offered mixed support for both affect regulation and instrumentalization as applied to PSM. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Cross-reactive immunogenicity of group A streptococcal vaccines designed using a recurrent neural network to identify conserved M protein linear epitopes.

The M protein of group A streptococci (Strep A) is a major virulence determinant and protective antigen. The N-terminal sequence of the protein defines the more than 200 M types of Strep A and also contains epitopes that elicit opsonic antibodies, some of which cross-react with heterologous M types. Current efforts to develop broadly protective M protein-based vaccines are directed at identifying potential cross-protective epitopes located in the N-terminal regions of cluster-related M proteins for use as vaccine antigens. In this study, we have used a comprehensive approach using the recurrent neural network ABCpred and IEDB epitope conservancy analysis tools to predict 16 residue linear B-cell epitopes from 117 clinically relevant M types of Strep A (~88% of global Strep A infections). To examine the immunogenicity of these epitope-based vaccines, nine peptides that together shared ≥60% sequence identity with 37 heterologous M proteins were incorporated into two recombinant hybrid protein vaccines, in which the epitopes were repeated 2 or 3 times, respectively. The combined immune responses of immunized rabbits showed that the vaccines elicited significant levels of antibodies against all nine vaccine epitopes present in homologous N-terminal 1-50 amino acid synthetic M peptides, as well as cross-reactive antibodies against 16 of 37 heterologous M peptides predicted to contain similar epitopes. The epitope-specificity of the cross-reactive antibodies was confirmed by ELISA inhibition assays and functional opsonic activity was assayed in HL-60-based bactericidal assays. The results provide important information for the future design of broadly protective M protein-based Strep A vaccines.

Lycopene intervention reduces inflammation and improves HDL functionality in moderately overweight middle-aged individuals.

The management of overweight subjects by interventions aimed at reducing inflammation is highly desirable. To date, observational studies have identified a link between increased dietary antioxidant intake and reduced cardiovascular morbidity. However, direct trial evidence regarding the ability of antioxidants to influence inflammation is lacking. Therefore, this study examined lycopene's ability to lower systemic and high-density lipoprotein (HDL)-associated inflammation in moderately overweight middle-aged subjects. Serum was collected before and after a 12-week intervention from 54 moderately overweight, middle-aged individuals. Subjects were randomised to one of three groups: control diet (<10 mg lycopene/week), lycopene-rich diet (224-350 mg lycopene/week) and lycopene supplement (70 mg lycopene/week). HDL was subfractionated into HDL(2&3) by rapid ultracentrifugation. Compliance was monitored by assessing lycopene concentration in serum and HDL(2&3). Systemic and HDL-associated inflammation was assessed by measuring serum amyloid A (SAA) levels. HDL functionality was determined by monitoring the activities of paraoxonase-1 (PON-1), cholesteryl ester transfer protein (CETP) and lecithin cholesterol acyltransferase (LCAT). Lycopene increased in serum and HDL(2&3) following both lycopene interventions (P<.001, for all), while SAA decreased in serum following the lycopene supplement and in HDL(3) following both lycopene interventions (P<.05 for all). PON-1 activity increased in serum and HDL(2&3) in both lycopene groups (P<.05, for all). Furthermore, the activity of CETP decreased in serum following the lycopene supplement, while the activity of LCAT increased in serum and HDL(3) following both lycopene interventions (P<.05 for all). These results demonstrate that in moderately overweight, middle-aged subjects, increasing lycopene intake leads to changes to HDL(2&3), which we suggest enhanced their antiatherogenic properties. Overall, these results show the heart-protective properties of increased lycopene intake.

α-Tocopherol induces proatherogenic changes to HDL2 & HDL3: an in vitro and ex vivo investigation.

INTRODUCTION: High density lipoproteins (HDL) have considerable potential for improving cardiovascular health. Additionally, epidemiological studies have identified an inverse relationship between α-tocopherol intake and cardiovascular disease, which has not been translated in randomised controlled trials. OBJECTIVES: This study assessed if increased α-tocopherol within HDL(2) and HDL(3) (HDL(2&3)) influenced their antiatherogenic potential. In the first of two in vitro investigations, the oxidation potential of HDL(2&3) was assessed when α-tocopherol was added following their isolation. In the second, their oxidation potential was assessed when HDL(2&3) were isolated from serum pre-incubated with α-tocopherol. Additionally, a 6-week placebo-controlled intervention with α-tocopherol assessed if α-tocopherol influenced the oxidation potential and activities of HDL(2&3)-associated enzymes, paraoxonase-1 (PON-1) and lecithin cholesteryl acyltransferase (LCAT). RESULTS: Conflicting results arose from the in vitro investigations, whereby increasing concentrations of α-tocopherol protected HDL(2&3) against oxidation in the post-incubated HDL(2&3), and promoted HDL(2&3)-oxidation when they were isolated from serum pre-incubated with α-tocopherol. Following the 6-week placebo-controlled investigation, α-tocopherol increased in HDL(2&3), while HDL(2&3) became more susceptible to oxidation, additionally the activities of HDL(2&3)-PON-1 and HDL(2)-LCAT decreased. CONCLUSION: These results have shown for the first time that α-tocopherol induces changes to HDL(2&3), which could contribute to the pathophysiology of cardiovascular disease.

A randomized controlled trial of the effects of intensive sit-to-stand training after recent traumatic brain injury on sit-to-stand performance.

OBJECTIVE: To examine the effectiveness of intensive practice of sit-to-stand on motor performance, exercise capacity and exercise efficiency in traumatic brain-injured patients during early inpatient rehabilitation. DESIGN: Single-blind randomized controlled pilot study. SETTING: Brain injury rehabilitation unit. SUBJECTS: Twenty-four subjects who had recently sustained a severe traumatic brain injury (TBI) were randomized into an experimental (n = 13) and a control (n = 11) group. INTERVENTIONS: In addition to their usual rehabilitation programme, subjects in the experimental group participated in four weeks of intensive training of sit-to-stand and step-up exercises with the aim of improving performance of sit-to-stand. The control group did no additional sit-to-stand or step-up training. MAIN OUTCOME MEASURES: Total number of sit-to-stands in 3 min as a measure of motor performance; peak oxygen consumption during a maximal 3-min sit-to-stand test (Vo2peak) as a measure of exercise capacity; oxygen consumption during a 3-min equivalent workload sit-to-stand test (Vo2equiv) as a measure of exercise efficiency. Pre- and post-training measurements were made. RESULTS: The exercise programme resulted in a 62% improvement in motor performance (number of repetitions of sit-to-stand in 3 min) for the experimental group compared with the control group's 18% improvement (p < 0.05). There was no significant difference between groups for changes in exercise capacity or efficiency. In the experimental group, the increase in Vo2peak from pre-test to post-test correlated with the increase in sit-to-stand repetitions (p < 0.05). CONCLUSIONS: Intensive task-specific training is recommended as an important component of rehabilitation early following severe traumatic brain injury.