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Biology subjects

Stanelle-Bertram, S.

Publications and source records attributed to Stanelle-Bertram, S..

4 recordsLinked to original sources

Temporal Profiling of Upper-Layer Neurons Reveals Changes in the Molecular Landscape Upon Maternal Immune Activation

Neuronal differentiation is a dynamic, multi-layered process that transforms progenitor cells into functionally integrated neurons, yet the coordinated molecular programs underlying this transition remain incompletely understood. Here, we define the developmental trajectory of murine upper-layer cortical neurons using an integrated multi-omics approach combining transcriptomics and proteomics across key stages of neurogenesis. We find that neuronal identity emerges gradually through coordinated transitions from RNA processing and splicing programs toward synaptic and metabolic maturation. Integration of matched transcriptomic and proteomic datasets reveals a compact set of concordant molecular modules that define this trajectory, highlighting post-transcriptional regulation as a central driver of neuronal maturation. We further show that maternal immune activation (MIA), a model of prenatal inflammation, deranges this developmental program. MIA induces sustained upregulation of Wnt signalling pathways alongside a downregulation of synaptic regulators, without detectable global alterations in DNA methylation. These molecular changes are accompanied by defects in neuronal positioning during cortical development, linking altered molecular trajectories to functional outcomes. Together, our findings establish a temporal molecular framework of neuronal differentiation and demonstrate that prenatal environmental perturbations reshape cortical development primarily through post-transcriptional and signalling-based mechanisms.

neuroscience↗

Snapshot of in-cell protein contact sites reveals new host factors and hijacking of paraspeckles during influenza A virus infection

Influenza A virus (IAV) hijacks host cellular machinery, but many virus-IAV interactions and contacting protein sites remain uncharacterised, particularly those dependent on intact cellular architecture, such as membrane-associated or phase-separated compartments. Here, we applied in-cell cross-linking mass spectrometry (XL-MS), integrated with AlphaFold-based structural modelling and functional assays, to map protein-protein contact sites in IAV-infected human cells. This approach revealed previously unrecognised virus-host interactions linked to spatially organised processes, including the maturation pathway of HA through the membrane-bound ER- Golgi system, the novel interaction of M2 with the membrane-embedded LAT1 amino acid transporter, and the progressive disassembly of paraspeckles-phase-separated compartments in the nucleus. We validate M2-LAT1 interaction and paraspeckle disassembly in human primary lung epithelial cells and show that the paraspeckle disassembly constitutes a new and unique infection mechanism through which IAV releases RNA-binding proteins that support viral RNA replication. These findings advance the understanding of IAV manipulation of host cellular processes and illustrate how the integrative in-cell structural system biology approach captures native host-pathogen interactomes, infection pathways, and host cell perturbations.

microbiology↗

Hamsters are a model for COVID-19 alveolar regeneration mechanisms: an opportunity to understand post-acute sequelae of SARS-CoV-2

A relevant number of coronavirus disease 2019 (COVID-19) survivors suffers from post-acute sequelae of severe acute respiratory syndrome coronavirus 2 (PASC). Current evidence suggests a dysregulated alveolar regeneration in COVID-19 as a possible explanation for respiratory PASC symptoms, a phenomenon which deserves further investigation in a suitable animal model. This study investigates morphological, phenotypical and transcriptomic features of alveolar regeneration in SARS-CoV-2 infected Syrian golden hamsters. We demonstrate that CK8+ alveolar differentiation intermediate (ADI) cells occur following SARS-CoV-2-induced diffuse alveolar damage. A subset of ADI cells shows nuclear accumulation of TP53 at 6- and 14-days post infection (dpi), indicating a prolonged arrest in the ADI state. Transcriptome data show the expression of gene signatures driving ADI cell senescence, epithelial-mesenchymal transition, and angiogenesis. Moreover, we show that multipotent CK14+ airway basal cell progenitors migrate out of terminal bronchioles, aiding alveolar regeneration. At 14 dpi, presence of ADI cells, peribronchiolar proliferates, M2-type macrophages, and sub-pleural fibrosis is observed, indicating incomplete alveolar restoration. The results demonstrate that the hamster model reliably phenocopies indicators of a dysregulated alveolar regeneration of COVID-19 patients. The results provide important information on a translational COVID-19 model, which is crucial for its application in future research addressing pathomechanisms of PASC and in testing of prophylactic and therapeutic approaches for this syndrome.

pathology↗

Structures and functions linked to genome-wide adaptation of human influenza A viruses

Human influenza A viruses elicit short-term respiratory infections with considerable mortality and morbidity. While H3N2 viruses circulate since almost 50 years, the recent introduction of pH1N1 viruses presents an excellent opportunity for a comparative analysis of the genome-wide evolutionary forces acting on both subtypes. Here, we inferred patches of sites relevant for adaptation, i.e. being under positive selection, on eleven viral protein structures, from all available data since 1968 and correlated these with known functional properties. Overall, pH1N1 had more patches than H3N2 viruses, especially in the viral polymerase complex, while antigenic evolution is more apparent for H3N2 viruses. In both subtypes, NS1 had the highest patch and patch site frequency, indicating that NS1-mediated viral attenuation of host inflammatory responses is a continuously intensifying process, elevated even in the longtime-circulating subtype H3N2. We confirmed the resistance-causing effects of two pH1N1 changes against oseltamivir in NA activity assays, demonstrating the value of the resource for discovering functionally relevant changes. Our results represent an atlas of protein regions and sites with links to host adaptation, antiviral drug resistances and immune evasion for both subtypes for further study.

bioinformatics↗