FEBS Open Bio

Deoxyribonucleic acid (DNA) stands as one of the most foundational concepts in life sciences, essential for students to master. However, when surveyed about the forces that stabilize the double-stranded DNA structure, many students exhibited a conceptual bias-- favoring base pairing as the primary stabilizing force, while overlooking the equally critical role of base stacking interactions. To investigate the origins of this misconception, students conducted a comprehensive analysis of 35 widely used textbooks. Their findings revealed that one-third of these texts explicitly emphasized base pairing as the sole stabilizing force in their written content. Furthermore, two-thirds of the textbook contained illustrations that reinforced this bias, visually highlighting base pairing while neglecting base stacking. Recognizing this bias, students embarked on a literature review to gain a more accurate and nuanced understanding of DNA stabilization. Through this research, we identified three concept areas--DNA structure and function, environmental effects on DNA, and DNA-protein interactions--to illustrate how base pairing and base stacking work in concert to stabilize the antiparallel double helical structure of DNA. This interplay between base pairing and base stacking is crucial not only for the structural integrity of DNA, but also for its biological functionality. By addressing this conceptual bias, we aim to promote a more balanced and scientifically accurate representation of DNA stabilization in educational materials.

Developing scientific reading skills is critical for undergraduate STEM students due to scientific literatures unique formatting and use of specialized jargon. Generative AI tools such as ChatGPT offer students the ability to ask questions about what they are reading interactively. Previously, we reported the development of a ChatGPT-assisted reading guide that combined structured, active reading strategies with using ChatGPT to clarify unfamiliar words and concepts in real time. In the initial study, undergraduates found the use of the ChatGPT-assisted reading guide helpful in their understanding of an abstract and introduction of a journal article. Here, the ChatGPT-assisted reading guide was used in a journal club assignment for an undergraduate chemistry course. ChatGPT transcripts were analyzed for common types of interactions, and students were surveyed about their experience. Overall, students reported that using the ChatGPT-assisted reading guide was helpful in understanding the article and helped them have more productive class discussions. However, some students also expressed skepticism about using AI tools, citing concerns about accuracy of AI-generated information and the effect of using AI on their own learning.

BackgroundThe global adoption of English-medium instruction (EMI) in higher education has introduced complex implementation challenges, whose severity often depends on the resources available within specific educational contexts. Evidence remains limited in public medical schools in under-resourced, non-Anglophone countries, serving a socioeconomically and educationally diverse student population. In such settings, the direct transfer of existing EMI integration models presents significant practical challenges. ObjectiveThis exploratory, observational, monocentric study aimed to investigate medical students perceptions and attitudes towards EMI implementation at the Faculty of Medicine and Pharmacy of Rabat (FMPR) in Morocco, to evaluate their readiness for EMI adoption. MethodsA cross-sectional survey was administered to 102 second-curriculum-level medical students at FMPR. The 23-item questionnaire included Likert-type scales and multiple-choice questions across four domains: demographic data, self-reported English language (EL) proficiency, language perceptions and attitudes, and EMI needs. Bivariate, univariate and multivariate logistic regression analyses were conducted to determine the effects of the explanatory variables on EMI choice. ResultsThe sample comprised 65 females and 37 males. Most participants reported using EL speaking and listening skills "often" on a daily basis, while writing and reading skills were reported as being used "rarely." Participants rated their general EL proficiency and their academic listening and reading skills as "good." Overall, 92.2% (94/102) of students were strongly in favor of implementing EMI at FMPR. Bivariate analysis showed significant positive associations between EMI choice and age (P = .035), course year (p < .001), interest in learning EL (P = .011), and the belief that EL should be the language of higher education (P < .001). Preference for EMI increased alongside course year, peaking at 96.4% among students in the third and fourth years. Multivariate logistic regression confirmed that being in course years 3 and 4 (OR = 8.83, 95% CI [2.05-172.69], P = .009), having an interest in learning EL (OR = 6.90, 95% CI [1.31-36.16], P = .022), and believing that EL should be the language of higher education (OR = 6.38, 95% CI [1.87-21.72], P =.003) were significant positive predictors of EMI choice. ConclusionsMedical students at FMPR exhibit highly positive perceptions and attitudes toward the potential implementation of EMI, despite variations in their self-reported EL readiness. These findings provide actionable insights for the successful integration of EMI that extend beyond the Moroccan context, offering a valuable framework for medical institutions in other under-resourced, low- and middle-income, non-Anglophone settings across the Global South.

T/A cloning is a popular method for generating recombinant DNA plasmids. This method relies on single A:T nucleotide base pairs between PCR product ends and vector. Theoretically, the directionality of insert ligation with relation to the vector is random. However, we have continuously observed directionality bias using the pGEM-T Vector System for T/A cloning in a Course-based Undergraduate Research Experience (CURE). Cloning of over 400 inserts has shown directional bias higher than 74% (p-value < 0.0005) "sense" to the T7 promoter of the vector. Awareness of biased insertion in our applications reduces time and cost in cloning and downstream analyses.

BackgroundThe global decline in the number of physician-scientists, despite an increase in practicing physicians, underscores a critical need for integrating research training into medical education. Addressing this issue, we established an international research exchange program aimed to enhance scientific literacy, foster transferable skills, and align curricula with European standards through collaborative research experiences. MethodologyThe program enabled reciprocal student mobility, involving eleven medical undergraduates who conducted month-long basic science research projects. Participants also completed comprehensive pre-training in scientific communication, safety protocols, and ethics, and were required to participate in local public engagement events. Feedback from participants, which we present here, was collected via three anonymous, voluntary questionnaires: pre-program, post-program and post-1-year follow-up, which we provide here to support similar initiatives. ResultsDespite challenges and delays due to the COVID-19 pandemic, the program met its objectives, demonstrating adaptability and effective resource management. Feedback revealed significant improvements in participants confidence in research methodologies, critical appraisal of scientific literature, and motivation for future research involvement. ConclusionThis project highlights the potential of structured international exchange programs, particularly among smaller institutions, to address gaps in medical education, enhance scientific training and opportunities in translational research for undergraduates, and cultivate the next generation of physician-scientists.

Introduction: Glioblastoma multiforme (GBM) remains the most lethal primary brain tumor with median survival of 14-15 months. Current prognostic markers inadequately stratify patient outcomes. PINK1 (PTEN-induced putative kinase 1), a mitochondrial kinase regulating mitophagy and cellular stress responses, has emerged as a promising prognostic candidate. Our preliminary analysis of 20 GBM cases demonstrated significant PINK1 expression with correlation to aggressive phenotypes (Turizo Smith et al., 2025). This multicenter study aims to prospectively validate PINK1 as a prognostic biomarker for survival and functional outcomes in a Latin American cohort. Methods and analysis: PINK1-GBM Colombia is a multicenter, observational cohort study across four tertiary hospitals in Bogota, Colombia (Hospital de Kennedy, Hospital El Tunal, Hospital Santa Clara and Hospital Universitario de la Samaritana). We will enroll at least 26-50 adults (18+ years) with newly diagnosed IDH-wild type GBM undergoing surgical resection. PINK1 expression will be quantified by immunohistochemistry (IHC) on formalin-fixed paraffin embedded (FFPE) tissue using standardized protocols. Primary outcomes: overall survival (OS) and progression-free survival (PFS). Secondary outcomes: functional status trajectories (KPS/ECOG). Follow-up extends 24 months with clinical, imaging (RANO 2.0), and telephone assessments. Survival analyses will employ Kaplan-Meier methods, log-rank tests, and Cox proportional hazards models adjusted for established prognostic factors. Ethics and dissemination: Approved by Universidad Nacional de Colombia Ethics Committee (Acta 001, February 5, 2026; Ref: 2.FM.1.002-CE-002-26), Subred Sur Occidente (P-AP-19-2025, July 11, 2025), and Subred Centro Oriente (CEI 067/2025, October 24, 2025). Conducted per Declaration of Helsinki and Colombian Resolution 8430/1993. Results will be disseminated via peer-reviewed publication, international conferences, and thesis submission.

BackgroundSpinocerebellar ataxia type 2 (SCA2) is a neurodegenerative disorder that shows cerebellar glucose hypometabolism, systemic hypermetabolism and weight loss. This study aimed to explore novel molecular biomarker candidates for SCA2, based on the assessment of blood glucose homeostasis. MethodsA case-control and correlational study was conducted in 79 Cuban patients with SCA2 and 83 sex- and age-matched control subjects during a fasting state. A subset of 20 SCA2 patients and 19 control individuals underwent an oral glucose tolerance test (OGTT). Several indices for assessing blood glucose homeostasis, derived from the fasting state or the OGTT, were included in the study. ResultsFasting glucose levels showed a small increase, whereas the QUICKI index for insulin sensitivity was slightly decreased among patients. Markers of glucose homeostasis derived from the OGTT were no different between patients and controls. Fasting insulin levels, QUICKI, McAuleys, HOMA2-%S, HOMA2-IR, and HOMA2-%{beta} indices showed weak to moderate correlations with markers of body composition. McAuleys, TyG, HOMA2-IR, and HOMA2-%{beta} indices correlated with the age at onset, progression rate, or INAS count. ConclusionsSCA2 patients with mild to moderate ataxia do not have any major alteration in blood glucose homeostasis. Markers of glucose homeostasis associate with body composition and has modifying effects on disease severity and progression rate in patients with SCA2, with McAuleys index showing effects more consistently. Further studies are needed to describe the changes in blood glucose homeostasis in the different stages of disease, and to confirm the validity of McAuleys index as a candidate biomarker for SCA2 clinical severity and progression.

The question of whether islet neogenesis occurs in adult humans has been a subject of long-standing debate. To explore the characteristics of islet endocrine cells associated with pancreatic ducts, we employed imaging mass cytometry to examine pancreatic tissues from individuals across different age groups, including those with prediabetes or type 2 diabetes (T2D). Our analysis revealed the presence of all five pancreatic islet endocrine cell types, along with two types of non-hormone-expressing endocrine cells, located within or immediately adjacent to the ducts. These cells were most abundant in infancy, with a gradual decline observed through adulthood. Notably, ductal {beta} cells predominated in infancy, whereas ductal cells became more prevalent in adulthood, and significantly increased in the group aged over 60 years. Obesity further increased the ductal {beta} cells in the subjects aged over 60 years. Under prediabetic and T2D conditions, an increase in all duct-related endocrine cells was observed. These findings indicate that ductal cells may serve as a reservoir for new pancreatic endocrine cells, offering potential insights into the promotion of endogenous {beta} cell regeneration in diabetic patients. Highlights{bigcirc} Characterization of various islet endocrine cell types related to ducts in human pancreas. {bigcirc}The insulin-positive cells are the dominant cells among all duct-related islet endocrine cell types during the infancy period, however, the glucagon-positive cells become the dominant cells in adulthood. {bigcirc}T2D, Obesity, and aging are involved in the increase in the number of duct-related endocrine cells.

Osteosarcoma (OS) is an aggressive bone cancer that most commonly affects children and young adults. OS exhibits a high degree of genomic complexity, as well as cellular plasticity, and dynamic transcriptional regulation is suggested to contribute to treatment resistance and metastasis. Cell lines are well characterized as models to advance our knowledge on OS biology. HOS and U2OS cells have increased invasiveness and higher migratory ability compared with MG63. In this study, we employed a tandem array of consensus transcription factor response elements (catTFREs) proteomic approach to characterize transcription factor (TF) regulatory networks related to OS aggressiveness. We mapped 7,594 proteins and enriched 352 transcription factors and coregulators. When we integrated proteomics with cell line specific gene expression and chromatin accessibility we classified the proteins into different OS cell line dependent sub-clusters and identified TFs and coregulators common for all cell lines and specific for individual cell lines. We demonstrate that RUNX2, MYBL2 and HMGA2 are specifically enriched in HOS and U2OS and may be linked to the cell aggressiveness. ETV5, JUNB, NFIX and ZEB1 were among TFs specific to MG63. Our analysis provides a more comprehensive understanding of the transcriptional drivers that shape OS regulatory landscapes and may have future therapeutic implications.

Over the past two decades, Higher Education Institutions have increasingly prioritised transferrable skills to enhance graduate employability. Graduate Attributes (GAs) now act as key indicators of student competencies for both learners and employers. Final-year research projects, typically high in credit value, represent capstone experiences that promote subject expertise and GA development through research, written work, and oral presentations. This study analyses pre- and post-project survey data from RQF Level 6 biomedical and biomolecular science students at a Russell Group University over four years (2019-2023). Most projects were laboratory-based, though the 2020-2021 cohort completed theirs remotely due to COVID-19. Students reflected on expectations and experiences of GA development, subject knowledge, and employability. Initial responses revealed anxiety and uncertainty, particularly among the 2020-2021 cohort, but most anticipated gains in skills and employability. Post-project feedback confirmed this, identifying critical thinking, confidence, resilience, collaboration, and future focus as key outcomes. Digital capability was notably strengthened, especially during remote delivery. The findings emphasise the importance of a shared understanding of GAs in bioscience education and the value of embedding structured reflection and preparatory support to help students recognise and articulate their evolving skills.

BACKGROUNDSubcutaneous white adipose tissue (scWAT), a key metabolic and endocrine organ, is inevitably exposed during radiotherapy (RT). While RT is a cornerstone of cancer treatment, its efficacy is limited by toxicity to surrounding healthy tissues. Ultra-high dose rate (FLASH) RT has emerged as a promising modality capable of preserving tumor control while reducing normal tissue damage - the so-called FLASH effect. Clinical evidence indicates that childhood exposure to conventional (CONV) RT is associated with long-term dysmetabolism and WAT dysfunction. However, the impact of FLASH-RT on WAT has not been investigated. AIMTo compare the effects of FLASH- and CONV-RT on adipocyte function and scWAT homeostasis, and to identify molecular and structural changes associated with each modality. METHODSWe evaluated the effects of FLASH- and CONV-RT on adipocytes and scWAT using a dedicated linear accelerator capable of delivering both modalities. Experiments were performed in the human SGBS preadipocyte/adipocyte cell line and in a mouse model subjected to proximal hind limb irradiation, with analyses conducted 70 days post-exposure. RESULTSRT impaired adipogenic differentiation in a dose-dependent manner, with a relative sparing effect of FLASH at 4-8 Gy. Mature adipocytes exhibited radioresistance, with protection by FLASH at 8 Gy. In vivo, both regimens reduced fat mass without affecting body weight, with greater loss following CONV-RT. Transcriptomic profiling of scWAT revealed inflammatory and neurodegenerative signatures after CONV-RT, whereas FLASH-RT induced minimal transcriptional changes. Histological and ultrastructural analyses confirmed increased cellular damage, vacuolization, lipid spill-over, and reduced PLIN1 expression, predominantly in CONV-treated mice. CONCLUSIONSWAT homeostasis is sensitive to conventional RT, whereas FLASH-RT better preserves tissue structure and function, with implications for long-term metabolic health in cancer survivors.

BackgroundN4-acetylcytidine (ac4C) modification plays a critical role in cancer development. Exploring ac4C modification in laryngeal squamous cell carcinoma (LSCC) may help elucidate its pathogenesis. MethodsLSCC-related datasets were obtained from GEO. After preprocessing and annotating single-cell data, malignant cells were identified by CNV scoring and further divided into subpopulations. Malignant epithelial cells (MECs) were identified and subclustered based on ac4C-related gene activity. Prognostic genes were screened using Cox regression and machine-learning approaches, followed by validation in clinical samples using qPCR. The biological and immunological relevance of these genes was further explored through immune infiltration, immunotherapy response, and mutation analyses. ResultsThe 14,465 identified MECs were classified into five subgroups (MEC1-5), among which MEC3 showed the strongest association with the ac4C gene set. Machine-learning analysis of MEC3-derived genes yielded seven prognostic markers, including BARX1, FHL2, NXPH4, PKMYT1, TNFAIP8L1, CRLF1, and CENPP. qPCR confirmed their differential expression between tumor and adjacent normal tissues. These genes were significantly associated with alterations in the tumor immune microenvironment, with high-risk patients showing increased immune infiltration and immune activity. ConclusionSeven ac4C-related prognostic genes were identified that may contribute to LSCC progression by modulating the tumor immune microenvironment, providing potential therapeutic insights.

BackgroundCompetence-Based Education (CBE) in physiotherapy aims to equip graduates with essential capabilities for safe and effective practice. Frameworks often include domains like clinical reasoning, communication, and professionalism. Despite its alignment with healthcare needs, CBE implementation in higher education remains inconsistent. Many educators still rely on behaviourist paradigms focused on passive learning and binary assessments, which inadequately reflect professional competence. Constructivist and progressive models offer more suitable alternatives yet are underutilized. Objective: This study explores the feasibility of integrating programmatic assessment (PA) to better support capability development and learner-centred education. MethodThis randomized controlled trial will be conducted a University of Applied Sciences across two campuses in Switzerland. Students from Cohort PHY25 enrolled in the BSc Physiotherapy program will be included. Students are assigned to PA in two formats, individual coaching (IG A) and group coaching (IG B), or to a sham PA without any coaching or reflective support (CG). Feasibility will be evaluated through session attendance, completion of all program components, and implementation fidelity. Secondary outcomes include staff readiness, wellbeing, workload, and learning gain. DiscussionThis study explores the feasibility and educational impact of implementing programmatic assessment in undergraduate physiotherapy education. If successful, PA may enhance competence development. Findings will inform curricular redesigns and support the shift toward learner-centred, capability-based assessment strategies in health professions education. Trial registrationRegistry of Efficacy and Effectiveness Studies under the number: #25261.2v1.

Preclinical research in traumatic brain injury (TBI) continues to significantly increase knowledge and yield a large number of peer-reviewed studies, but translation of these results to the clinical setting has been minimal. Rigor and transparency factors such as concealment of group allocation (e.g., "blinding) or ensuring that reagents are identifiable are critical in ensuring that scientific studies are replicable and translatable. Yet, nearly all efforts aimed at measuring these factors have concluded that reporting practices are problematic and incomplete. One way to improve transparency of reporting practices is to require that authors address a set of transparency related items in some way, such as a checklist or a paper section. Recently, Journal of Neurotrauma, a leading publisher of preclinical TBI research, instituted a required rigor-related section, which is explained to authors via a set of transparency, rigor, and reproducibility (TRR) instructions (one example for each manuscript type). These documents include specific transparency sections explaining blinding, power calculations, protocols, code, and data deposition. Experimental Neurology is a journal that is similar in size, impact and topic but the journal does not have explicit instructions to authors about transparency items. The purpose of this study was to assess the degree to which transparency reporting items were included in published manuscripts comparing reporting practices in the Journal of Neurotrauma and Experimental Neurology. We used a commercial software, SciScore, which is an AI tool tuned to detect rigor/transparency sentences in published manuscripts and count the number found (roughly dividing by the number expected) to obtain a score. Overall, SciScore found that in 6 of 8 items that were explicitly asked for, such as power calculations, investigator blinding, inclusion criteria, attrition, and data were significantly greater (more than 10%) compared to Experimental Neurology. However in Journal of Neurotrauma papers with the extra rigor section, 3 of 4 rigor items that were not explicitly asked for in the template rigor documents, such as subject demographics or transparent antibody reporting were not different from Experimental Neurology. One item, reporting of the sex of subjects was significantly better in Experimental Neurology. This shows that the Journal of Neurotrauma required rigor section is effective in improving reporting, but it would be far better if sex as a biological variable and transparent reporting of reagents (items present on major checklists including NIH rigor criteria) would be included.

Mutations in MAPT, the tau gene, give rise to forms of frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17T), with abundant filamentous tau inclusions in brain cells. Some mutations that encode missense and deletion variants can give rise to a clinical picture of Picks disease and filaments made of three-repeat tau. Here we report the electron cryo-microscopy (cryo-EM) structures of tau filaments from individuals with MAPT mutations D252V, G272V, S320F and {Delta}G389-I392. The two-layered Pick fold was present in the individuals with mutations D252V and {Delta}G389-I392. By contrast, mutations G272V and S320F gave rise to a more open variant of the Pick fold, with residues 272-341 rotated by 20-25{degrees} with respect to the rest of the structure. These findings show that missense mutations within the filament core can modify the Pick fold, generating closely related structural variants. In addition, we were able to reconstitute the Pick fold and some of its variants using seeded assembly with recombinant 0N3R tau carrying 12 serine or threonine to aspartate substitutions (PAD12) and missense mutations D252V, G272V or S320F. This work provides a foundation for the development of structure-based diagnostic and therapeutic approaches.

Accurately modeling antibody-antigen interactions requires distinguishing intrinsic binding affinity ("protein-interaction") from protein biophysical properties ("protein-quality"), including folding, stability, and expression. However, high-throughput mutational measurements commonly used to train and benchmark computational models often conflate these effects, obscuring the true determinants of molecular recognition. Here, we present an experimental and analytical framework to disentangle protein-interaction effects from protein-quality effects in single-domain antibody (VHH)-antigen binding. Using a large-scale deep mutational scanning (DMS) dataset spanning four VHH-antigen complexes, with single and double mutations in both partners, we introduce control binders to quantify protein-quality changes independently of protein-interaction. This enables decomposition of experimentally measured affinity into protein-interaction and protein-quality components at scale. Leveraging the disentangled dataset, we evaluated state-of-the-art structure- and sequence-based models for protein-quality and protein-interaction prediction and show that their performance largely reflects protein-quality rather than protein-interaction effects. Our results highlight a major confounder in current datasets and suggest that accounting for protein-quality will be essential for training next-generation affinity-prediction models. Nomenclature Antibody related termsO_LIPrimary VHH: The VHH of a VHH-antigen complex for which the paratope and the epitope weremutated. C_LIO_LIControl VHH: A second VHH that binds to the same antigen as the primary VHH but has non-overlapping epitope positions and therefore does not bind to any of the mutated antigen positions. C_LI Affinity-related termsO_LIReal Affinity: "The strength of the interaction between two [...] molecules that bind reversibly (interact)" 1. In the context of antibody-antigen binding, it quantifies interactions between active proteins (which are expressed and correctly folded 2 and are therefore functionally and biologically active (see below). It is commonly quantified by the equilibrium dissociation constant, KD. C_LIO_LIObserved affinity ({degrees}KD): The interaction strength experimentally measured between two molecules. Unlike real affinity, this value is confounded by the biophysical properties of the individual binding partners, specifically their folding, stability, and expression levels. Consequently, the observed affinity often differs from the real/intrinsic affinity if a significant fraction of the protein population is inactive 3. NOTE: Unless otherwise specified, {degrees}KD is reported in - log10 space. For example, a {degrees}KD of -9 corresponds to 10-9M or 1nM. C_LIO_LIChange in observed affinity ({Delta}{degrees}KD): The shift in the observed affinity between two proteins upon mutation, reported as the log10-transformed fold change. A value of 1 reflects a 10-fold difference, a value of 2 a 100-fold difference, etc. This aggregate change resolves into two distinct biophysical components 2, 4: O_LIProtein-interaction change: The change in the intrinsic thermodynamic affinity between the two binding partners, each in its active state (i.e., the specific change in interface Gibbs free energy because both enthalpy and entropy are considered). C_LIO_LIProtein-quality change: The change in the fraction of the mutated protein population that is biologically active - meaning it is expressed, correctly folded, and stable 2, 5. O_LIFolding: The process that guides the polypeptide chain toward its native conformation, which is a prerequisite for forming a functional binding site. C_LIO_LIStability: The thermodynamic capacity to maintain the folded structure over time and under physiological conditions. Stability (decrease in Gibbs free energy from the unfolded to the folded state) ensures the binding interface remains intact and prevents competing processes such as aggregation 6. C_LIO_LIExpression: The steady-state abundance of the protein. This is largely dependent on proper folding and stability, as cellular quality control mechanisms degrade proteins that fail to fold or remain stable at functional concentrations. C_LI C_LI C_LIO_LIChange in relative affinity ({Delta}{Delta}{degrees}KD): the difference between the {Delta}{degrees}KD of the primary VHH compared to the control VHH for a given epitope mutation. C_LI Model-related termsO_LIESM-IF1 sc: Single-chain (sc) structure-conditioned inverse folding model (ESM-IF1), using the isolated monomer structure of the mutated protein: either the VHH or the antigen 7. C_LIO_LIESM-IF1 mc: Multi-chain (mc) structure-conditioned model (ESM-IF1), using the full complex structure (both antibody and antigen) 7. C_LIO_LIStability prediction score: Score that represents the predicted change in stability based on a single mutation, normally represented as {Delta}{Delta}G. C_LI

Research using model organisms to tackle questions in life sciences and biomedical sciences has been in the spotlight of scientific literature for the better part of the twentieth century. This attention has perceptibly faded over the last twenty years, at least. We set to document this process by examining the publication trends of 48 journals encompassing a broad range of topics and impact factors for eight classic model organisms. We found that the representation of model-organism research has been in continuous decline in the last three decades, with a significant acceleration since 2010. We investigated the origin of the change, from the size of research communities to the shifts in topics and in use of model organisms. While model organism communities appear stable, model organism papers are outpaced by the rest of scientific literature. Also, among papers using model organisms, we note a progressive shift toward applied research, with differences between different model organism species. The mouse, in particular, logically remains the preferred system to study diseases, while non-mouse model organisms continue to be used predominantly to dissect mechanisms of life. We reflect on the consequences of the fading representation that we measured for the future of life sciences. Fundamentally, model organisms afford a direct access to causality in life sciences and their fading from the picture may impact life sciences as a whole. More pragmatically, it will also affect funding, and thereby jeopardizes the maintenance of model organism resources such as repositories built over decades.

Parkinsons disease (PD) is the second most common neurodegenerative disease, resulting from accumulation of -synuclein (-syn) in midbrain dopaminergic neurons and progressive neuronal loss. The most relevant species of -syn, oligomers, may exert neurotoxicity in a variety of mechanisms. Accumulation of misfolded -syn in the endoplasmic reticulum (ER) lumen induces ER stress conditions that leads to activation of the Unfolded Protein Response (UPR) and its main sensor PKR-like ER kinase (PERK). PERK is critical for cell fate determination - under prolonged ER stress, it may direct cell towards pro-apoptotic pathways. Targeting of -syn aggregation or UPR by genetic and pharmacological approaches proved effective in preclinical models of PD by previous research. Thus, in the present study, we aimed to determine the potential effect of combination of small-molecule inhibitors of -syn aggregation and ER stress-mediated PERK signaling (namely anle138b and AMG44) in a novel, 3D in vitro model of PD. We demonstrate that combination of both anti-aggregation and ER stress-targeting approaches amplifies neuroprotection against PD in organoid model in terms of increased neuronal metabolic activity, decreased -syn phosphorylation and aggregation, reduced dopaminergic cell death, and restoration of proteostasis.

The enzyme nitric oxide synthase (NOS) breaks down the semi-essential amino acid L-arginine (L-Arg) in the cell to produce citrulline and nitric oxide (NO). NO is a crucial signalling molecule in cells that controls the metabolism of fats and carbohydrates. The aim of this study was to investigate two important genes in the L-Arg-NOS-NO signalling pathway, AMPK and ACC-1, as markers of the molecular mechanisms that are triggered when liver cells sense elevated L-Arg. Mouse liver epithelial insulin-sensitive BNL CL2 cells were used as a model system and cultured with 0, 400 or 800 {micro}M L-Arg. Cell growth parameters were analysed alongside qRT-PCR based analysis of target transcripts involved in lipid and glucose metabolic pathways. In a further experiment, NOS inhibitor; L-NAME (40 mM) and external NO donor; SNAP (100 {micro}M) were added and the effect on target gene expression analysed. L-Arg addition impacted culture viability and cell growth. AMP-activated protein kinase (AMPK) was regulated in response to L-Arg addition with increasing extracellular concentrations elevating AMPK mRNA and protein expressions. L-NAME decreased target gene expression in an L-Arg addition dependent manner. SNAP (100 {micro}M) addition increased target gene expression after 6 and 24 h. NO, produced as a result of L-Arg addition and the factors L-NAME and SNAP, that regulate NO bioavailability, impacted BNL CL2 cell NO/AMPK/ACC-1 signalling pathways via regulating mRNA expression and subsequently protein expression.

A method to measure telomere length in S. cerevisiae was developed based on bioluminescence resonance energy transfer (BRET). The system uses energy transfer between a luciferase-Rif2 fusion protein and fluorescently tagged Rap1. The study demonstrates that the BRET ratio correlates with the Rap1/Rif2 complex at the telomeres and thus the availability of telomeric Rap1 binding sites. This enables the measurement of telomere length in living cells. The system was able to reproduce reported deviations in telomere length in mutants lacking telomere length regulators, cells treated with telomere length modifying compounds and strains expressing inducible telomerase. The BRET ratio linearly correlated with the average number of telomeric nucleotides derived from long-read sequencing data using a novel algorithm for telomere length calculation. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/711003v1_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@1850c4dorg.highwire.dtl.DTLVardef@1ead295org.highwire.dtl.DTLVardef@1a76358org.highwire.dtl.DTLVardef@6b3183_HPS_FORMAT_FIGEXP M_FIG C_FIG