Central European Institute of Technology – Masaryk University

The proline-rich region of the tubulin-associated unit (TAU) protein is of substantial interest in understanding neurodegenerative diseases due to its interaction with bridging integrator 1 (BIN1). The associated gene BIN1 is substantially associated with the development of Alzheimer's disease. Previous studies have underlined the importance of the conformation of the proline-rich region of TAU and the effect of its phosphorylation. In this study, we investigate the change in compactness between a four times phosphorylated TAU fragment (210-240) compared to the unphosphorylated (non-P) form using computational means. We apply our Ensemble Reconstruction from Fragments (ERF) approach to create two unbiased conformational ensembles from which a reweighted ensemble is derived that agrees with observables from nuclear magnetic resonance experiments. The resulting shift of the radius of gyration indicates a preference for relatively compact conformations for the non-P form, while the restraints derived from the experimental data do not substantially influence the compactness of the phosphorylated peptide.

This work investigates aperiodic bursts of neuronal activity, referred to as neuronal avalanches, which are thought to support flexible information processing in Lewy body (LB) disease. We compared avalanche-derived features across LB disease phenotypes (prodromal dementia with LB and Parkinson's disease, PD), with healthy controls (HC). Based on the premise that focal neurodegeneration alters whole-brain dynamics, we examined whether the "richness" of brain dynamics was associated with clinical symptoms and with the microstructural integrity of catecholaminergic nuclei - the right caudal locus coeruleus (rcLC) and the substantia nigra pars compacta (SNpc). The sample comprised 30 HC, 56 cognitively normal individuals with core clinical features of dementia with LB (CN-CCF), 34 individuals with mild cognitive impairment with LB (MCI-LB), and 30 advanced PD patients. Neuronal avalanches were extracted from source-reconstructed resting-state EEG and described by their count, the number of unique spatial patterns (flexibility), hemispheric symmetry of flexibility, and avalanche transition matrices. LC and SNpc integrity were assessed using neuromelanin-sensitive MRI and free-water diffusion imaging, respectively. Lewy body disease groups exhibited increased flexibility relative to HC, which was, in prodromal groups, associated with cognitive fluctuations and REM sleep behavior disorder symptoms, but not parkinsonism. Flexibility was negatively related to rcLC integrity, which was lowest in MCI-LB. These findings suggest that elevated flexibility reflects dysregulated brain dynamics linked to malignant non-motor features of LB diseases and to the caudal LC involvement.

ObjectiveDrug‐resistant epilepsy (DRE) is defined as the failure of two antiseizure medications (ASMs) to achieve complete seizure control, affecting approximately 30% of epilepsy patients. In some cases, additional ASMs and surgical approaches are also unsuccessful. Ultra‐Refractory Epilepsy (URE) is a newly described entity, characterized by the failure of six distinct epilepsy treatment strategies, including ASMs, surgical resection, and neurostimulation techniques. This study aimed to analyze demographic and clinical data of URE patients managed at the Brno Epilepsy Center, a member of the European Reference Network (ERN)—EpiCARE.MethodsWe conducted a retrospective cohort study with a prospective follow‐up component. Adult patients hospitalized for epilepsy at the Brno Epilepsy Center between 2017 and 2023 were retrospectively identified, and their outcomes were prospectively assessed in February 2025 through medical record review and structured telephone interviews. URE patients were identified, and their demographic and clinical data were analyzed.ResultsIn this study, 1034 patients' charts were reviewed, and 62 patients (6%) met the criteria for URE. In the URE cohort, the median age of epilepsy onset was 9 years (range 1–60 years), and the median age at the time of evaluation was 35 years (range 21–67 years). The median seizure frequency was nine seizures per month (range 1–900), with 26 (42%) of patients experiencing extremely high seizure frequencies (>20 seizures/month). Structural etiology was the most common cause (29 [47%] patients). Among the cohort, 57 (92%) patients received a combination of ASMs, surgical resection, or neurostimulation, while only 5 (8%) patients were managed exclusively with ASMs.SignificanceURE represents an extreme therapeutic challenge within epilepsy centers. The high seizure burden and limited treatment response in this population highlight the urgent need for novel therapeutic strategies and further research into this newly defined entity.Plain Language SummaryUltra‐refractory epilepsy (URE) is a newly described form of extremely difficult‐to‐treat epilepsy. In our study of 62 patients, all had already failed at least six different treatment attempts, including medications, brain surgery, or nerve stimulation. Most patients continued to have frequent seizures despite all available therapies, and only a small minority achieved long‐term seizure freedom. These findings show that URE is a severe condition with a major unmet medical need, highlighting the importance of developing new treatment strategies.

We have recently identified transcription factor c-Myb as a negative prognostic factor in osteosarcoma (OSA) patients associated with metastatic disease. Transcriptomic analysis identified creatine kinase B (CKB) as one of the most deregulated genes in OSA cell lines with depleted MYB. CKB is a component of the creatine/phosphocreatine system that plays a key role in maintaining cellular energy homeostasis and energy transport to sites with high demand. This study was therefore conducted to investigate the functional significance of CKB in OSA. Deregulation of CKB by c-Myb in OSA cells was analyzed using gain-of-function/loss-of-function approach. Transactivation of the CKB promoter by c-Myb was assessed using a reporter assay. CRISPR/Cas9, RNAi and cyclocreatine were used to inhibit the expression/activity of CKB in OSA cells. Cell growth, colony-forming capacity, cell migration, chemosensitivity in vitro and metastatic capacity in vivo was examined. CKB protein effectors were identified using liquid chromatography-mass spectrometry (LC-MS) in data-independent acquisition-parallel accumulation serial fragmentation mode. CKB was validated as c-Myb target in OSA cell lines. Depletion of CKB using CRISPR/Cas9 resulted in slower migration of OSA cells in vitro and reduced metastatic capacity in immunodeficient mice. siRNA and cyclocreatine inhibited OSA cell migration as well but in this case, cell proliferation was also reduced. A total of 8474 protein groups were quantified, with 147 downregulated and 143 upregulated protein groups associated with the CKB knockout phenotype. The deregulated proteins were enriched for those associated with cell migration and motility. N-cadherin, an established regulator of cell migration, was identified as a target of CKB signaling and its role in OSA cell migration and metastasis was confirmed. c-Myb - CKB - N-cadherin axis was identified as pathway regulating OSA cell migration and metastasis.

The final chapter is comparative. It analyses Central European executive dualism, emphasising presidents during international crises of war. It focuses on the impact of presidential activism on the functioning of the executive in difficult times. In doing so, it draws on the theoretical perspective introduced in the second chapter. The result is an original typology of Central European presidents based on their activism and role within executive dualism, especially in relation to prime ministers.

Voice-based health technologies are growing rapidly, but they lack standardized terminology, which hinders interdisciplinary collaboration, research quality, and clinical translation. The objective of this work is to develop universally accepted definitions in the rapidly evolving field of vocal biomarkers, as part of the VOCAL (Vocal Biomarker Guidelines for Ontology, Classification, Application, and Logistics) initiative, a structured, international consensus-based framework that aims to provide standards, and guidelines. VOCAL is a rigorous, international, multi-stage consensus-building study conducted in 2024-2025. Multi-institutional collaboration between representatives from the Bridge2AI-Voice Consortium (North America) and the eVoiceNet Network (European Union), culminating in an in person workshop at the 2025 Bridge2AI Voice Symposium. A group of 24 international experts in medicine, clinical research, speech and language, audio signal processing, statistics, methodology, regulation, ethics. VOCAL's iterative process involved five rounds of review, feedback, and an in-person workshop at the international 2025 Bridge2AI Voice Symposium, ensuring the incorporation of diverse perspectives and achieving a robust agreement on the proposed definitions. Consensus-based definitions for vocal biomarkers, spanning from broad concepts (biomarker, digital biomarker, vocal biomarker) to domain-specific measures (cardio-respiratory acoustic, voice, speech/articulatory, cognitive/language). A hierarchical continuum model of vocal biomarkers was established. We first distinguished between the concepts of vocal measures and vocal biomarkers. We then defined terms from broad, overarching concepts (Level 0: Biomarker, Digital Biomarker, Vocal Biomarker) to more specific physiological and cognitive domains (Level 1: Cardio-Respiratory Acoustic; Level 2: Voice; Level 3: Speech/Articulatory; Level 4: Cognitive/Language, including linguistic and paralinguistic subtypes). This work provides a shared vocabulary that is essential for fostering communication through interdisciplinary collaboration, improving the quality and efficiency of research and development, and ensuring the ethical, reliable, and scalable deployment of future voice-based health technologies. It lays foundational groundwork for upcoming guidelines and standards, which are crucial for advancing the field of vocal biomarkers into widespread clinical utility.

BackgroundInflammatory bowel diseases (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), are chronic conditions characterized by periods of clinical remission and relapse. Pediatric cases (pIBD) often have a more complicated disease course, where approximately 30% will develop a relapse within a year of diagnosis. Identifying prognostic markers for pIBD is important to optimize treatment and improve long-term outcomes. Our aim was to analyze the tissue microbiome, identify microbial prognostic markers, and validate their predictive power in non-invasive fecal samples.ResultsTissue and fecal microbiome were characterized from a prospective cohort comprising 33 therapeutically naïve pCD and 23 pUC patients, and 26 non-IBD pediatric controls, using amplicon 16S rRNA gene sequencing. Disease relapse was monitored for one year. At diagnosis, relapsing pCD patients exhibited a significantly decreased alpha diversity and altered beta diversity in tissue compared to non-relapsing pCD patients. Specific taxa were differentially abundant in relapsing pCD, with Barnesiella being the most depleted genus in tissue samples. Receiver Operating Characteristic (ROC) analysis identified Barnesiella (AUC = 0.818), Butyricimonas, and Collinsella as individual microbial tissue markers discriminating pCD relapse. Combining Barnesiella with the weighted Pediatric Crohn’s Disease Activity Index (wPCDAI) further enhanced the specificity and sensitivity of the ROC analysis (AUC = 0.872 in tissue, 0.852 in feces), suggesting potential for non-invasive prognostic markers from stool.ConclusionsTissue and fecal microbial markers can predict relapse in pCD patients with high prognostic power, providing a basis for precision medicine and personalized treatment strategies in pIBD.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13099-025-00766-5.

Rift Valley fever virus (RVFV) is an arbovirus from the Phenuiviridae family that can cause severe disease in humans and livestock, with outbreaks resulting in substantial economic losses. Despite the availability of attenuated vaccines for animals, there is no approved preventive or therapeutic agent for human RVFV infections. Moreover, the safety and efficacy of the current veterinary vaccines remain uncertain. The RVFV L protein, a 250 kDa polymerase, plays a key role in viral replication and transcription, containing endonuclease, RNA-dependent RNA polymerase (RdRp), and cap-binding domains. Structurally conserved across related viruses and functionally analogous to the influenza virus polymerase, the L protein is a compelling antiviral target. In our study, we screened a library of polymerase inhibitors and identified several compounds with inhibitory activity against the RVFV polymerase. We validated their effect using both live virus assays and a minigenome luciferase reporter system. Resistance mutants were generated, and key mutations conferring resistance to the inhibitors were identified and characterized. Some of these key mutations were structurally analyzed via cryo-electron microscopy, using a new structure of the apo form of wild-type RVFV L protein resolved at 3.5 Å. This structure provides critical insights into how the mutations can influence inhibitor binding and RVFV polymerase function. These findings provide insight into how these mutations may confer resistance by affecting inhibitor binding and polymerase activity.

Abstract BACKGROUND Astrocytoma, IDH-mutant, is the most common primary brain tumor in young adults, with peak incidence between 30 and 40 years of age. It is defined by mutations in the IDH1 or IDH2 genes and the absence of 1p/19q codeletion, and it frequently harbors alterations in ATRX and TP53. Rarely, astrocytoma, IDH-mutant, amay exhibit primitive neuronal differentiation, morphologically resembling “small round blue cell” tumors or large anaplastic embryonal-like cells. METHODS We analyzed 18 cases of astrocytoma, IDH-mutant, with primitive neuronal differentiation. In 11 cases where both the primitive neuronal and glial components were available, macrodissection was performed by a pathologist. Each component was subjected to separate genetic (next-generation sequencing) and epigenetic (DNA methylation profiling) analyses. Morphological and immunophenotypic features were also evaluated. RESULTS The primitive neuronal component was characterized by absent or markedly reduced GFAP expression, positivity for neuronal markers, a high Ki-67 proliferation index, and frequent TTF1 expression. This component also exhibited distinct epigenetic signatures and copy number alterations compared to the glial component. All tumors were high-grade, with extensive copy number variations, frequent MYCN amplification, and RB1 loss. DISCUSSION Astrocytoma, IDH-mutant, with a primitive neuronal component expands the morphological spectrum of IDH-mutant astrocytomas and presents a significant diagnostic challenge. Recognition of this rare subtype is critical due to its aggressive biological behavior. This work was supported by Masaryk University in Brno, Czech Republic, under Grant MUNI/A/1621/2024, the Ministry of Health, Czech Republic, grant project no. NU23-03-00100 and by the project National Institute for Cancer Research (Programme EXCELES, ID Project No. LX22NPO5102) - Funded by the European Union - Next Generation EU.

Familial hypercholesterolemia (FH) is a disorder of cholesterol metabolism characterized by elevated LDL-cholesterol levels. The most common cause of FH is pathogenic variants in the LDL receptor (LDLR) gene. To shed light on the functional impact of selected LDLR variants, we functionally characterized 16 LDLR genetic variants alongside 10 control variants. We performed in vitro assays based on transient expression of WT and mutant LDLRs in LDLR-deficient Chinese hamster ovary cells. We used flow cytometry to analyze the relative amount of LDLRs expressed on the cell surface and the relative amount of internalized LDL. In addition, we analyzed the expression and maturation of LDLR protein by Western blotting. Of the 16 studied variants, two variants (p.(Asn272Thr) and p.(Arg574Leu)) did not exhibit a defect in LDLR function, one variant (p.(Ala540Thr)) exhibited a defect in LDL binding and/or internalization despite normal LDLR cell surface expression, and the remaining 13 variants had a detrimental effect on both LDLR cell surface expression and LDL internalization. The information presented in this study contributes to the clinical classification of LDLR variants and a more precise diagnosis of FH patients, highlighting the type of defect each variant produces.