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Acetic acid-induced translational repression involves eIF2B body formation and Ded1 sequestration into stress granules in yeast.

Elucidating the physiological impact of acetic acid stress and the corresponding yeast responses is essential for advancing fundamental biology and improving industrial alcoholic fermentation. Despite numerous genome-wide studies, information on the effects of acetic acid stress on yeast translational regulation remains limited. We found that a sublethal concentration of acetic acid (35 mM, 0.2% v/v) causes translational repression, accompanied by the formation of eIF2B bodies and the phosphorylation of eIF2α, both of which are involved in the regulation of translation initiation. Acetic acid also caused the sequestration of Ded1, a DEAD-box RNA helicase crucial for translation initiation, into stress granules. Removal of acetic acid restored translational activity and the proper localization of eIF2B and Ded1, indicating the reversibility of acetic acid-induced translational repression. Furthermore, when yeast cells were pretreated with 0.05% acetic acid, translational repression under subsequent 0.2% acetic acid stress was attenuated in wild-type cells but not in hrk1Δ cells. This indicates that Hrk1, a Pma1 activator, is required to sufficiently enhance tolerance to acetic acid-induced translational repression. These findings provide novel insights into the physiological effects of acetic acid stress on translational activity and translation-related factors in yeast cells.

Saccharomyces cerevisiae

Molecular Determinants and Therapeutic Targeting of Stop Codon Readthrough in Eukaryotic Translation.

Accurate translation termination is essential for proteome integrity and in eukaryotes is primarily governed by the release factors eRF1 and eRF3, which ensure precise recognition of stop codons and efficient release of nascent polypeptides. However, proteome integrity is challenged by mutations that generate premature termination codons (PTCs), leading to truncated, nonfunctional proteins and degradation of the aberrant transcript via nonsense-mediated mRNA decay (NMD). Collectively, these events account for ∼1800 human genetic diseases. Translational readthrough, the process by which near-cognate tRNAs decode stop codons and allow ribosomes to continue elongation beyond the stop codon, represents a possibility to suppress PTCs and restore full-length protein synthesis. Initially discovered in viruses as a mechanism to expand coding capacity, readthrough is now recognized as a regulated feature of eukaryotic gene expression influenced by both cis-acting sequence elements and trans-acting factors. Recent evidence highlights the remarkable context dependence of readthrough, revealing variation across transcripts, tissues, and developmental stages. In this review, we examine the molecular determinants that define stop codon recognition and readthrough efficiency, with particular emphasis on nucleotide context. We further discuss the mechanisms and binding sites of small molecules that promote PTC readthrough, and summarize the clinical development landscape of readthrough-inducing compounds for the treatment of diseases caused by nonsense mutations.

Humans

A Conserved 3'UTR Stem-loop Directs UPF1/eIF4AIII-Dependent Regulation of GABARAPL1 mRNA.

RNA-binding proteins (RBP) interact with mRNA untranslated regions containing cis-regulatory elements to govern mRNA localization, stability, and translational efficiency. Among these trans-regulatory factors, RNA helicase UPF1 is a central factor which play a role in multiple mRNA decay pathways, including nonsense-mediated mRNA decay (NMD). NMD is triggered when an exon-junction complex (EJC) is located downstream of a premature termination codon. However, in some cases, NMD can be activated in an EJC-independent manner through mechanisms involving the 3'UTR. In the present study, we focused on the GABARAPL1 3'UTR, as previous studies had shown that this region plays a key role in NMD targeting, although the underlying molecular mechanism had not yet been elucidated. Unlike canonical NMD targets such as SC35, we found that the chemical inhibition of eIF4AIII helicase activity did not affect GABARAPL1 transcript levels, indicating that this transcript is regulated through its 3'UTR via an EJC-independent mechanism. We therefore investigated the potential presence of cis-regulatory element within the 3'UTR of GABARAPL1 which can regulate mRNA and protein levels in a UPF1-dependent manner. Furthermore, we identified a conserved RNA region spanning nucleotides 364-421 involved in GABARAPL1 targeting and used biochemical analysis to demonstrate the direct binding of UPF1 and eIF4AIII to this RNA region, to analyse its secondary structure in solution, and to map the protein-binding sites. By complementing these approaches with molecular modelling, we showed that this stem-loop adopts a stable global fold but a local flexibility and dynamic behaviour properties. Together, our results support the role of UPF1 and eIF4AIII as specific regulators of GABARAPL1 transcript and reveal a novel RNA regulatory element within its 3'UTR, which provides a completely unexpected binding site for these factors.

3' Untranslated Regions

Cost-effectiveness analysis of omeprazole for preventing esophageal stricture in patients with Zargar grade 2b and 3a corrosive esophageal injuries: A trial-based economic evaluation.

BACKGROUND: Corrosive esophageal injury frequently results in esophageal stricture requiring repeated endoscopic dilatation and substantial healthcare expenditure. This study evaluated the cost-effectiveness of omeprazole plus standard treatment compared with standard treatment alone for preventing esophageal stricture in adult patients with Zargar grade 2b and 3a corrosive esophageal injuries. METHODS: A trial-based economic evaluation was conducted alongside a randomized controlled trial from the healthcare provider and patient perspectives. Twenty patients were randomized to receive either standard treatment alone (n = 10) or standard treatment plus omeprazole (n = 10). Direct medical costs were analyzed using the incremental cost-effectiveness ratio. Deterministic one-way sensitivity analysis and probabilistic sensitivity analysis using Monte Carlo simulation were performed. RESULTS: The incidence of corrosive esophageal stricture was 20% (2/10) in the omeprazole group and 70% (7/10) in the standard treatment group (relative risk, 0.29; 95% confidence interval, 0.08-1.05; Fisher's exact test, P = .070). Omeprazole plus standard treatment reduced healthcare costs by THB 4642.30 per patient from the provider perspective and THB 5476.60 per patient from the patient perspective. The intervention remained the dominant strategy across all deterministic sensitivity analyses. Probabilistic sensitivity analysis demonstrated that 68.3% and 78.8% of simulations favored omeprazole from the provider and patient perspectives, respectively. CONCLUSION: Omeprazole plus standard treatment may represent a cost-effective strategy for adult patients with Zargar grade 2b and 3a corrosive esophageal injuries. However, these findings should be considered preliminary and require confirmation in larger multicenter randomized controlled trials.

Humans

Long-term safety and efficacy of ponesimod, an oral S1P1 receptor modulator, in relapsing-remitting multiple sclerosis (RRMS): Results from randomized phase 2b core and extension studies spanning up to 13 years.

BACKGROUND: Ponesimod demonstrated efficacy and safety in relapsing-remitting multiple sclerosis (RRMS) in 24-week phase-2 core study, further confirmed by an interim combined analysis of the core and open-label long-term extension (LTE) studies (NCT01093326; up to 8 years). Current study evaluated safety and efficacy of ponesimod using combined core and LTE studies data for up to 13 years. METHODS: Of 393 participants completing the core study, 353 (90%) entered LTE, having 3 treatment periods (TP). In TP1 (∼1.85 years), participants continued core treatment (ponesimod: 10, 20, or 40 mg QD) whereas placebo-treated participants were re-randomized (1:1:1) to respective ponesimod doses. In TP2 (TP2 and TP3 combined duration: ∼10.4 years), participants on 40 mg were re-randomized (1:1) to 10/20 mg, while others continued same dose; in TP3 all participants received 20 mg. Study outcomes included safety and efficacy (ARR, time-to 24-week confirmed-disability-accumulation [24-week CDA], total T1-weighted Gadolinium-enhanced (T1 Gd+) lesions, new/enlarging T2 lesions and Combined Unique Active Lesions [CUALs]). RESULTS: For 20 mg dose, total 92.4% participants experienced ≥1 TEAEs (73.1% mild/moderate severity) and 19 (13%) participants discontinued study. Mean (95% CI) ARR=0.14 (0.10-0.20); Kaplan-Meier estimate (95% CI) of confirmed relapse and 24-week CDA=52.5% (42.3-63.5) and 31.3% (22.6-42.3). Mean [SD] T1 Gd+ lesions decreased from ponesimod baseline (2.62 [7.06]) to 12.4 years (0.26 [1.48]), mean (95% CI) CUALs per participant/year=3.97 (2.75-5.73). CONCLUSION: Ponesimod treatment for up to 13 years was not associated with new safety concerns. Participants continued to experience low levels of disease activity consistently across clinical and MRI outcomes.

Humans

Endovascular treatment after stroke beyond 24 h vs 6-24 h: a propensity score-matched cohort study.

BACKGROUND: Endovascular thrombectomy (EVT) is the standard treatment for acute ischemic stroke due to anterior circulation large vessel occlusion (LVO) within 6-24 h. However, the safety and feasibility of EVT for anterior circulation strokes beyond 24 h remain uncertain. METHODS: We conducted a retrospective cohort study of consecutive patients with anterior circulation LVO who underwent EVT at Changhai Hospital from 2018 to 2023. Patients were stratified into late (6-24 h) and very late (>24 h) windows. Propensity score matching (PSM) was performed to adjust for baseline imbalances, including age, sex, NIHSS, ASPECTS, occlusion location, perfusion parameters, and vascular risk factors. The primary outcome was functional independence (modified Rankin Scale [mRS] ≤ 2) at 3 months. Secondary outcomes included successful reperfusion (TICI 2b-3) and symptomatic intracranial hemorrhage (sICH). RESULTS: Among 1043 screened patients, 429 patients with anterior circulation LVO were included after exclusions, comprising 373 in the late window and 56 in the very late window. PSM yielded 42 matched pairs. Compared with the late window group, the very late window group showed no statistically significant differences in functional independence (54.8% vs. 57.1%; OR = 0.908, 95% CI 0.382-2.153, p = 0.830), successful reperfusion (88.1% vs. 92.9%; OR = 1.800, 95% CI 0.481-7.096, p = 0.460), sICH (2.4% vs. 9.5%; OR = 0.232, 95% CI 0.012-1.652, p = 0.200), intraprocedural complications (26.2% vs. 19.0%; OR = 1.508, 95% CI 0.540-4.362, p = 0.440), or postoperative complications (33.3% vs. 35.7%; OR = 0.900, 95% CI 0.363-2.219, p = 0.820). CONCLUSIONS: In this selected, single-center cohort of anterior circulation LVO patients undergoing EVT, treatment initiated beyond 24 h appeared to have comparable effectiveness and safety to treatment initiated within 6-24 h. Definitive evidence requires confirmation from adequately powered randomized controlled trials.

Humans

Genomic characterization and pathogenicity of ruminant Listeria monocytogenes isolates in a murine oral infection model.

Listeria monocytogenes is a major foodborne pathogen; its ruminant isolates display zoonotic characteristics, causing similar clinical signs in humans, including abortion and encephalitis. However, data on whole genome sequencing and pathogenicity of ruminant L. monocytogenes isolates remain sparse. This study aimed to analyze the genotypic characteristics of L. monocytogenes isolates from ruminants with listeriosis. Furthermore, we assessed the in vivo pathogenicity of four ruminant L. monocytogenes isolates, characterized via whole-genome sequencing-based genetic clustering, in orogastrically inoculated mice. The isolate LM18 (serotype 1/2b, ST224, SL6178) had the lowest lethal dose compared to the other three isolates including previous hypervirulence type (serotype 4b, ST1, SL1) and caused secondary bacteremia in lungs, with sustained bacterial loads in the spleen and liver. Genomic (listeria pathogenicity island -1 and -3) and virulence gene (actA and llsX) mutation analyses associated with virulence suggested from well-recognized studies could not elucidate the virulence of the isolates. SSI-1, which only exists in the isolate LM18 (serotype 1/2b, ST224, SL6178), may help L. monocytogenes survive in the gastrointestinal environment, thereby affecting its virulence. Further research should investigate the role of SSI-1 in the pathogenicity of L. monocytogenes. Moreover, additional studies utilizing larger datasets of ruminant isolates are required to validate our genotypic characterization and to obtain a comprehensive picture of further genotypic differences crucial for L. monocytogenes pathogenicity.

Animals

Ramu stunt virus genome reveals previously unreported segments and nucleocapsid domain duplication in Mechlorovirus.

Ramu stunt virus (RmSV), a member of the genus Mechlorovirus within the family Phenuiviridae, was previously described as a six-segmented RNA virus infecting sugarcane. In this study, we re-examined type material and additional isolates using high-throughput sequencing and RT-PCR validation, revealing that RmSV possesses a nine-segmented genome, making it the largest reported in the Phenuiviridae. This expanded architecture includes duplicated RNA segments (RNA 2a and RNA 2b) encoding nucleocapsid-like proteins and two novel segments (RNA 7 and RNA 8). Comparative analysis showed that RNA 2a and 2b share about 84% amino acid identity, while RNA 5 encodes a third nucleocapsid homolog, indicating unprecedented domain redundancy. Structural modeling confirmed that all three nucleocapsid proteins maintain a conserved fold despite low sequence identity, with electrostatic mapping suggesting differential RNA-binding potential. Additionally, RNA 6 encodes a hypothetical protein structurally similar to the rice stripe virus disease-specific S-protein, implicating a role in symptom development. Transcript abundance analysis revealed RNA 6 as the most highly expressed segment across isolates. These findings revise the genomic composition of RmSV, highlight mechanisms of genome plasticity and adaptive evolution in plant-infecting bunyaviruses, and underscore practical implications for diagnostic assay design, resistance breeding, and biosecurity surveillance.

Genome, Viral

Evolutionary expansion of the NF-Y gene family in bivalves and divergent subunit responses to thermal and pathogenic stress in the noble scallop.

Nuclear factor Y (NF-Y) is a conserved eukaryotic transcription factor complex that specifically interacts with the CCAAT motif. Prior research has demonstrated that this gene family participates in various biological processes, encompassing growth, development, and stress responses, across a broad spectrum of organisms. However, research on the role of the NF-Y family in bivalves remains limited. In this study, we comprehensively identified the NF-Y family in 34 bivalve species, and further investigated its expression in the noble scallop Chlamys nobilis. A total of 296 NF-Y genes were identified and classified into three subfamilies, NF-YA, NF-YB, and NF-YC. Phylogenetic analysis revealed that NF-YA and NF-YC have remained relatively conserved, whereas NF-YB has undergone significant expansion. Additionally, while substantial disparities in gene copy numbers exist across species, the motif composition and exon-intron structures within each subfamily demonstrate notable conservation. Tissue expression profiling revealed distinct expression patterns among CnNF-Y genes, with several members exhibiting relatively high transcript abundance in gonadal tissues. Furthermore, qRT-PCR results demonstrated that CnNF-YA2, CnNF-YB6, and CnNF-YC were significantly and continuously upregulated under heat stress. Conversely, several genes, particularly CnNF-YA2, CnNF-YB3, and CnNF-YB4, exhibited dynamic transcriptional responses to Vibrio parahaemolyticus exposure. These findings enhance our understanding of the evolutionary trajectory and functional diversification of the NF-Y gene family in bivalves, laying a theoretical foundation for future research on thermal adaptation, immune regulation, and molecular breeding in scallops.

Animals

Active Site Assembly by SMG5 as a Mechanism for SMG6 Endonuclease Licencing in Nonsense-mediated mRNA Decay.

Nonsense-mediated mRNA decay (NMD) is a conserved eukaryotic surveillance pathway that eliminates transcripts containing premature termination codons (PTCs). Substantial progress has been made in defining the transcript features that mark aberrant translation termination for NMD activation, yet key mechanistic steps remain incompletely understood - including how recruitment of the central NMD factor UPF1 is coupled to the downstream effector phase in which targeted mRNAs are nucleolytically degraded. In metazoans, NMD employs an endonucleolytic route mediated by SMG6, a PIN-domain nuclease, alongside SMG5 and SMG7, which act downstream of PTC recognition. SMG5 has recently been proposed to licence SMG6 activity, yet the molecular basis of this licencing has remained elusive. Here, we combine AlphaFold structural predictions with biochemical assays to investigate interactions among human SMG5, SMG6, and SMG7. Structural models predict a high-confidence interface between SMG5 and SMG6 PIN domains that forms a composite active site: a conserved SMG5 aspartate (D893) complements the SMG6 acidic triad to reinstate the canonical tetrad required for PIN-domain catalysis. In vitro, SMG6 alone exhibits weak endonucleolytic activity, which is enhanced ∼10-fold by the SMG5 PIN domain. Mutational analyses confirm that conserved residues from both proteins are essential for this composite configuration. Our findings reveal that the SMG5 PIN domain, previously considered catalytically inert, plays a critical role in activating SMG6 by completing its active site. This work provides mechanistic insight into the SMG5-dependent licencing step and uncovers a composite PIN nuclease architecture at the heart of the metazoan NMD effector phase.

Nonsense Mediated mRNA Decay

Fructophilic lactic acid bacteria as a window into multi-scale convergent evolution.

Fructophilic lactic acid bacteria (FLAB) are a group of lactic acid bacteria with unique growth characteristics, that is, poor growth on glucose. Their growth is enhanced in the presence of fructose or external electron acceptors. These organisms inhabit fructose-rich environments such as flowers, fruits, and pollinating insects, particularly honey bees. Apilactobacillus spp. and Fructobacillus spp. are representatives of FLAB, although they belong to phylogenetically distant clades. These organisms commonly possess markedly small genomes with a low number of coding DNA sequences. Furthermore, their genomes are characterized by a markedly reduced number of genes involved in carbohydrate transport and metabolism. Genome reduction in FLAB reflects convergent adaptation to fructose-rich environments rather than general genome streamlining. The two distinct FLAB genera, Fructobacillus and Apilactobacillus, independently lost more than 100 genes in statistically similar orders. In contrast, genes involved in carbohydrate and amino acid metabolism exhibited reversed orders of loss between the two genera. Furthermore, FLAB genomes lack an intact bifunctional alcohol/aldehyde dehydrogenase gene (adhE), which causes their poor growth on glucose. A comparative genomic study suggested the evolutionary process underlying adhE gene decay during adaptation to the fructose-rich environments, including pollinating insects. In conclusion, FLAB represent a unique example of habitat-driven convergent reductive evolution that can be investigated across multiple biological scales - from individual genes to whole genomes - in the diverse LAB group with a wide range of habitats, and partially share the fructophilic evolution with eukaryotic yeasts found in fructose-rich habitats.

Fructose

Risk factors for loss of skeletal muscle mass in patients with chronic kidney disease on a low-protein diet.

OBJECTIVES: A low-protein diet (LPD) is recommended for patients with chronic kidney disease (CKD) to prevent a further decline in renal function. However, its impact on muscle mass in these patients remains unclear. This study investigated the risk factors for loss of muscle mass in patients with CKD on an LPD. METHODS: Eighty-four patients with predialysis CKD (59 men, mean age 61.9 &#xb1; 11.5 y) who participated in a multicenter randomized controlled trial initiated in 2014 were retrospectively reviewed. We collected data on baseline blood and urine tests, body composition, and dietary records at the start and end of the observation period. We evaluated muscle mass using the skeletal muscle index (SMI) and analyzed risk factors for a decrease in SMI during the 24-wk observation period, using logistic regression analysis. Variables with an association (P < 0.1) in univariate analysis, as well as age, sex, use of low-protein rice, and changes in protein intake, were subjected to multivariate analysis. RESULTS: SMI decreased in 50 patients (59.5%) during the observation period. Multivariate analysis identified significant associations of the SMI with serum albumin at baseline (odds ratio 0.11, 95% confidence interval 0.02-0.52, P = 0.004) and changes in energy intake while on the LPD (odds ratio 3.39, 95% confidence interval 1.00-11.43, P = 0.049). CONCLUSIONS: Risk factors for reduced SMI in patients with CKD on an LPD were malnutrition when initiating the LPD and reduced energy intake during its implementation. Clinicians should optimize nutritional status before initiation of an LPD and ensure adequate energy intake throughout treatment.

Humans

Sex differences in sleep and alcohol consumption outcomes following a digital insomnia intervention.

BACKGROUND: Poor sleep is a well-established risk factor for heavy drinking, and evidence suggests that sleep could serve as a potential treatment target for reducing alcohol consumption. The relationship between poor sleep and problematic drinking appears to be stronger among females, but no studies to date have assessed sex differences in alcohol consumption following insomnia treatment. Here, we combine the samples from two clinical trials to investigate sex differences in the effects of a digital cognitive behavioral therapy for insomnia (Sleep Healthy Using the Internet; SHUTi) on sleep and alcohol outcomes. METHODS: 184 heavy drinking individuals with insomnia (weekly binge episodes: 4/5&#x2009;+ drinks in one sitting for females/males; AUDIT score >7; ISI score >14) were randomly assigned to either the SHUTi program (n&#x2009;=&#x2009;102) or an active control program (n&#x2009;=&#x2009;82). Participants completed self-report assessments at baseline, immediately following the 9-week intervention period, and at 3 and 6-months post-intervention. RESULTS: Linear mixed effects models showed that SHUTi effects over time were stronger among females than males for improved sleep outcomes and reduced frequency of total and heavy drinking days (ps &#x2264; 0.038). Follow-up comparisons of within-group effect sizes revealed consistently larger reductions in alcohol consumption among SHUTi females (Cohen's d range = 0.92-2.23) than SHUTi males (Cohen's d range = 0.65-1.95). CONCLUSIONS: Findings suggest that SHUTi may be more efficacious in improving sleep and reducing drinking among females with insomnia compared to males. These results could have important implications for sex-specific prevention and treatment efforts for heavy drinking individuals with insomnia.

Humans

Sex modifies the association of high-altitude hypoxia with poor sleep quality and depression in school-age children and adolescents.

BACKGROUND: While chronic exposure to high-altitude hypoxia is known to impair sleep and mental health, whether these effects are sex-dependent remains unclear. This study addresses a critical gap by investigating how sex modifies the association between high-altitude hypoxia and risks of poor sleep quality, depressive symptoms, and their co-occurrence in children and adolescents. METHODS: In this cross-sectional study (March-May 2024), we enrolled 1,345 long-term residents of the Shannan Tibet Autonomous Prefecture (altitude: 3,650-4,800&#xa0;m) and 2,909 age-matched controls from low-altitude plains (Anhui Province, China). Sleep quality and depression were assessed using the Pittsburgh Sleep Quality Index (PSQI) and Montgomery-Asberg Depression Rating Scale (MADRS), respectively. Sex-stratified analyses and interaction metrics (RERI/AP/SI) were employed to evaluate additive and multiplicative effects. RESULTS: High-altitude residents exhibited significantly higher prevalence of poor sleep (24.2% vs. 18.7%, P&#x2009;<&#x2009;0.001), depression (23.6% vs. 15.3%, P&#x2009;<&#x2009;0.001), and their co-occurrence (12.6% vs. 8.6%, P&#x2009;<&#x2009;0.001) compared to low-altitude controls. A significant negative additive interaction (RERI&#x2009;=&#x2009;-&#x2009;0.78, 95% CI: -1.35 to -&#x2009;0.3; P&#x2009;<&#x2009;0.001) indicated that sex modifies the altitude-outcome association. Specifically: (1) high-altitude residence significantly increased poor sleep risk in males (OR&#x2009;=&#x2009;1.60, 95% CI: 1.26-2.03) but not in females (OR&#x2009;=&#x2009;1.39, 95% CI: 1.07-1.79); and (2) the expected female predominance in poor sleep observed in the plain region (OR&#x2009;=&#x2009;1.452, 95% CI: 1.191-1.769) disappeared in the plateau region (OR&#x2009;=&#x2009;0.865, 95% CI: 0.667-1.121). Similar patterns were independently replicated for depressive symptoms. These findings confirm that high-altitude exposure differentially increases risk in males rather than protecting females. CONCLUSION: Males show marked vulnerability to high-altitude-associated sleep and mood impairments, while females demonstrate resilience. Sex-tailored interventions for high-altitude populations, particularly targeting male adolescents, are urgently needed.

Humans

Early Worsening of Diabetic Retinopathy Following Initiation of Hybrid Closed-Loop/Automated Insulin Delivery Systems in Type 1 Diabetes: A Systematic Review and Structured Study-Level Synthesis.

BACKGROUND: Hybrid closed-loop (HCL) systems achieve rapid, algorithm-driven improvements in glycaemia in type 1 diabetes (T1D). Paradoxically, rapid improvement in glycaemic control is associated with early worsening of diabetic retinopathy (EWDR), a phenomenon established in the intensive insulin therapy era. Whether HCL initiation carries a clinically meaningful EWDR risk is unknown. No systematic review has previously addressed this question. METHODS: A systematic review and structured quantitative synthesis was performed using study-level estimates only (PROSPERO CRD:420261391951). MEDLINE, SCOPUS and Web of Science were searched to 14th May 2026. Studies reporting retinal outcomes in people with T1D initiating any HCL system were eligible. Two reviewers independently screened studies and extracted data. Risk of bias was assessed using ROBINS-I and certainty of evidence using the GRADE framework. EWDR incidence was summarised using study-level proportions, and comparative studies were summarised using study-specific risk ratios for HCL versus control therapy. Given substantial heterogeneity in EWDR definitions, retinal assessment timing, follow-up duration, and comparator groups, no pooled or meta-analytic estimates were derived. RESULTS: Eight studies (n&#x2009;=&#x2009;1487 participants; 860 HCL users) were included; all were observational and six were retrospective. EWDR varied markedly with the timing of retinal assessment. In studies assessing the retina within &#x2264;&#x2009;12&#x2009;months of HCL initiation, EWDR rates ranged from 8.9% to 26.5%. Studies with longer follow-up reported lower rates of retinal worsening or incident DR, 6.7% at 24&#x2009;months and 6.1% over a mean follow-up of 4.9&#x2009;years, suggesting that these studies may capture background DR progression rather than true early worsening. Three comparative studies included 177 HCL users and 315 controls; EWDR study-specific risk ratios were directionally inconsistent, ranging from 0.32 to 1.51, and were therefore not pooled. The most consistently identified risk factors were higher baseline HbA1c and older age. The magnitude of HbA1c reduction was not a consistent predictor of EWDR in the HCL context, in contrast to pre-HCL era evidence. Risk of bias ranged from moderate to critical and certainty of evidence was very low for all outcomes. CONCLUSIONS: Study-defined retinal worsening was reported in a minority of participants. The current evidence base is dominated by retrospective studies, variable retinal assessment timing, and inconsistent EWDR definitions. Well-designed prospective studies with protocol-specified retinal surveillance anchored to HCL initiation are required to generate reliable incidence estimates, identify risk factors, determine visual consequences, and inform standardised screening guidance.

Humans

Overcoming the hurdles: A systematic review of barriers to self-initiated exercise in trauma recovery.

There is substantial quantitative evidence in support of exercise as beneficial for trauma recovery, particularly in targeting the neurobiological mechanisms disrupted by trauma. It is therefore important to understand the circumstances under which individuals may avoid exercise, ultimately preventing them from accessing the wellbeing benefits. Some qualitative articles have identified the factors which may prevent an individual from choosing to engage in exercise outside of a structured intervention (self-initiated exercise), but there lacks a synthesis across these differing articles. This systematic review aimed to synthesise qualitative evidence on trauma survivors' experience of barriers to self-initiated exercise. A systematic search of six databases was conducted to identify peer-reviewed qualitative findings on the perceived barriers to self-initiated exercise engagement, with six articles meeting the inclusion criteria. Thematic synthesis revealed three key themes: Searching for Safety, Staying With The Trauma, and Costs of Exercise and Trauma. In their decision to exercise, trauma survivors negotiate many barriers: the physiological, social, and environmental threats to their safety, trauma-related dissociation, and the costs of both exercise and trauma weighed against competing recovery needs. The small number of included studies reflects the emerging nature of research in this area, but it may limit the transferability of the findings. Nonetheless, as the first of its kind, this systematic review collates the experience of barriers as a first meaningful, exploratory step towards addressing them in future research. Taken together, the findings underscore the importance of a trauma-informed approach to ensure exercise remains unimpeded for trauma survivors.

Humans

Biochemical Insights Into the Conserved Interactions of NMD Factors From Budding Yeast to Humans.

Nonsense-mediated mRNA decay (NMD) is one of the most extensively studied pathways of cytoplasmic mRNA degradation. It plays a critical role in diverse cellular processes by eliminating aberrant transcripts containing premature stop codons and by regulating the stability of physiological mRNAs. NMD factors were initially identified through genetic screens in S. cerevisiae (UPF1, 2, 3) and C. elegans (SMG-1, SMG5-7). Subsequent biochemical and genetic studies revealed the composition of NMD complexes and identified additional factors. A major protein hub for NMD is Upf1, an ATP-dependent RNA helicase that is part of two mutually exclusive NMD assemblies, the Upf1-Upf2-Upf3 complex and the Upf1-decapping complex, which contains the decapping enzyme and its co-factors. Here, we discuss recent findings, primarily from budding yeast, on the protein-protein interactions driving NMD complexes dynamics and their similarities to human NMD. Together, the N-terminal cysteine and histidine rich (CH) and helicase domains (HD) of Upf1 act as a hub for binding multiple partners. Upf1 is required for binding to NMD substrates and for the initiation of RNA degradation through decapping (yeast) or endonucleolytic hydrolysis (humans). We focus on the interplay between Upf2, Dcp2 and Nmd4 (yeast SMG6), which ensures the mutually exclusive formation of Upf1-bound subcomplexes modulating Upf1's affinity for RNA. Thus, the study of NMD factors interactions in different organisms sheds new light on the remarkable conservation of NMD molecular mechanisms.

Nonsense Mediated mRNA Decay

Pathogenic Variants in HEPACAM Alter Protein Localization and Interactome in Astrocytes of the Developing Mouse Cortex.

Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a rare leukodystrophy characterized by early-onset macrocephaly, white matter edema, seizures, and motor and cognitive decline. Approximately 25% of MLC patients carry HEPACAM pathogenic variants, many of which are dominant missense variants causing remitting MLC Type 2b. HEPACAM encodes hepatic and glial cell adhesion molecule (hepaCAM), also known as GlialCAM, an astrocyte-enriched transmembrane protein with important roles in astrocyte territory establishment, gap junction coupling, branching organization, synaptic function, and development of the gliovascular unit. The molecular mechanisms through which pathogenic variants in HEPACAM alter hepaCAM protein function in&#xa0;vivo and facilitate MLC pathogenesis during brain development remain largely unknown. Here, we used new viral tools and proximity-based proteomics to examine how three different dominant pathogenic variants alter hepaCAM subcellular localization and protein interactome in astrocytes of the developing mouse cortex. We found dramatic changes in hepaCAM distribution throughout the astrocyte, which were common to all mutants tested. We also observed significant changes in protein interactome between wild type and mutant hepaCAM, including decreased association with previously described hepaCAM-interacting proteins Connexin 43 and CLC-2. Moreover, we identified the epilepsy-associate potassium channel KCNQ2 as a novel hepaCAM interaction partner and found reduced association between KCNQ2 and pathogenic variants. Collectively, our data provide new insights into hepaCAM protein function in astrocytes during brain development, reveal altered protein dynamics of pathogenic variants, and provide a new resource to explore the molecular underpinnings of MLC pathogenesis.

Animals