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Sone, M.

Publications and source records attributed to Sone, M..

8 recordsLinked to original sources

Progressive Lineage Restriction of Bergmann Glia-like Progenitors during Postnatal Cerebellar Development

Bergmann glia-like progenitors (BGLPs) are transient astroglial progenitors in the postnatal cerebellum, but how their lineage potential changes during development remains incompletely understood. Our previous electroporation-based study suggested that P0 BGLPs possess broader lineage potential than P6 BGLPs. Here, we performed recombination-based lineage tracing by cerebellar surface application of tamoxifen to Ai9/+; GlastCreERT2/+ mice and temporally analyzed the progeny of BGLPs labeled at P0, P3, P6, and P8. We found that BGLPs undergo progressive lineage restriction during postnatal development. P0 BGLPs gave rise to Bergmann glial cells (BGs), inner granule cell layer astrocytes (IGL astrocytes), white matter astrocytes (WM astrocytes), and molecular layer inhibitory neurons (ML-INs), confirming our previous electroporation-based findings. In contrast, P3 BGLPs generated BGs, IGL astrocytes, and WM astrocytes, whereas P6 BGLPs generated BGs and IGL astrocytes, and P8 BGLPs generated predominantly BGs. Thus, BGLP lineage output was progressively restricted from four progeny categories at P0 to a predominantly BG-restricted output by P8, suggesting that BGLPs dynamically adjust their cellular output during postnatal cerebellar maturation. Additional temporal analyses suggested that ML-INs are unlikely to be generated directly from P0 BGLPs, but may arise indirectly through astrocyte-like progenitors (AsLPs) and inhibitory neuron progenitors (INPs). These findings identify postnatal BGLPs as a useful in vivo model for studying progressive lineage restriction and stage-specific cellular supply during cerebellar development.

developmental biology↗

Xenium-based spatial transcriptomic screening identifies candidate mRNAs localized in neuronal and glial processes of the adult mouse cerebellum

Subcellular mRNA localization contributes to local protein synthesis and functional compartmentalization in polarized cells, including neurons and glial cells. Although process-localized mRNAs have been identified by in situ hybridization, reporter-based analyses, and compartment-based transcriptomic approaches, systematic screening of such mRNAs within intact brain tissue while preserving tissue architecture remains challenging. Here, we developed a Xenium-based spatial transcriptomic screening strategy to identify candidate mRNAs localized in neuronal and glial processes in the adult mouse cerebellum. We focused on the molecular layer, which is densely occupied by Purkinje cell dendrites, Bergmann glial radial processes, and granule cell parallel fibers, but contains relatively few cell bodies. Using a Xenium Prime 5K dataset from adult mouse cerebellar sections, we first identified 199 genes whose transcripts were enriched in the molecular layer. By further focusing on DAPI-negative, process-rich regions and reducing contributions from molecular layer cell bodies, we extracted 126 candidate process-localized genes. Comparison with Allen Brain Atlas in situ hybridization data supported molecular layer localization with process-like patterns for 28 of 32 evaluable candidates. Integration with a published adult cerebellar single-nucleus RNA-seq atlas provided information on the possible cellular origins of these candidates. Gene Ontology analysis revealed enrichment of terms related to intracellular transport, cell projection structures, and synaptic function. These findings support the usefulness of a Xenium-based spatial transcriptomic first-screening strategy for identifying candidate process-localized mRNAs in intact brain tissue and provide a resource for studying RNA localization in cerebellar neuronal and glial processes.

Molecular Biology↗

Comprehensive transcriptomic and proteomic profiling of mTOR-related epilepsy

Malformations of cortical development (MCDs) are a major cause of drug-resistant epilepsy (DRE) in children. A subset of MCDs, including focal cortical dysplasia type II, tuberous sclerosis complex, and hemimegalencephaly, shares characteristic histopathological features and somatic mutations in genes within the PI3K-AKT-mTOR signaling cascade, and is termed mTORopathies. However, the molecular mechanisms that drive epileptogenesis and consequent uncontrollable seizures in these disorders remain poorly understood. Here, we performed integrated genomic, transcriptomic, and proteomic analyses of 60 surgical brain specimens from 42 patients with MCDs and 18 with mesial temporal lobe epilepsy. Targeted genomic sequencing identified 19 somatic mutations in PI3K-AKT-mTOR pathway genes, including novel variants in AKT3 (L51H) and MTOR (A512T). RNA sequencing comparing mTORopathy brains with controls, along with cross-validation using an independent public dataset, identified 287 consistently differentially expressed genes that were consistently altered. Downregulated genes were enriched in oxidative phosphorylation (OXPHOS) and mitochondrial metabolic pathways, whereas upregulated genes were associated with gliogenesis and cellular senescence. Proteomic profiling identified 44 differentially expressed proteins, including significant reductions in OXPHOS-related proteins (COX5B, NDUFS4, GOT2, RAB27B, and DKK3). Our study provides a patient-matched, multi-omics dataset of human mTOR-related epilepsies from a single-institution cohort. Integrated analyses across transcriptomic and proteomic layers highlight impairment of OXPHOS as a molecular hallmark of mTORopathies, Integrated transcriptomic and proteomic analyses identified impaired OXPHOS as a molecular hallmark, potentially contributing to focal hypometabolism in mTORopathy. These findings offer mechanistic insights into epileptogenesis and provide a valuable resource for understanding molecular pathologies and developing mechanism-based therapies for mTOR-related epilepsy.

neuroscience↗

Single-cell-resolved spatial multi-omics identifies mTOR-driven neuronal and astroglial pathogenicity underlying epileptogenic focal cortical dysplasia

Focal cortical dysplasia type II (FCDII) is a malformation of cortical development caused by somatic mutations in the mTOR signaling pathway. Two hallmark pathological cell types in FCDII, dysmorphic neurons (DNs) and balloon cells (BCs), arise as a result of somatic mutations in the mTOR signaling pathway and are implicated in the pathophysiology of drug-resistant epilepsy. However, how these somatic mutations reshape cell states within the human cortex remains poorly understood. Here, we integrate imaging-based spatial transcriptomics (iST), single-nucleus RNA sequencing, and proteomics of surgically resected FCDIIb tissue to define the transcriptional and proteomic profiles of DNs and BCs. Spatial mapping of iST data resolved transcriptional signatures in histologically validated DNs and BCs within FCDIIb sections. Integrative omics analysis further revealed that DNs show upregulation of PI3K-AKT-mTOR and p53-CROT metabolic programs accompanied by suppression of synaptic signaling, whereas BCs exhibit transcriptional signatures of reactive astrocytes with increased phagocytic and immune-like activity. These data delineate cell-type-specific consequences of somatic mTOR pathway mutations at single-cell resolution and reveal previously unrecognized metabolic and immunoregulatory mechanisms contributing to epileptogenesis in drug-resistant epilepsy. Our study establishes a spatial multi-omics framework for dissecting human cortical malformations and highlights potential therapeutic targets for drug-resistant epilepsy.

neuroscience↗

MEIS1 is Required for Establishing Bergmann Glia-Specific Properties in the Developing Cerebellum

Compared to normal multipolar astrocytes, Bergmann glial cells (BGs), specifically differentiated astrocytes in the cerebellum, possess unique unipolar morphology and additional cellular functions. However, the molecular mechanisms that confer BG-specific properties onto normal multipolar astrocytes remain unknown. Here, we show that the transcription factor, MEIS1, is involved in BGs acquiring their unique characteristics. Targeted disruption of Meis1 in the whole cerebellum or astroglial lineage cells resulted in a marked reduction of BGs accompanied by an increase in multipolar astrocytes in mice. Postnatal deletion of Meis1 in Bergmann glia-like progenitors (BGLPs), which produce both BGs and multipolar astrocytes, suppressed their differentiation into BGs while promoting into multipolar astrocytes. Single-cell RNA sequencing, immunohistochemistry, and ChIP-Atlas analyses indicated that MEIS1 directly upregulates expression of BG-specific genes, including Vimentin and Zeb2, which are known to contribute to the correct localization and the unipolar process formation of BGs. These findings suggest that MEIS1 promotes the endowment of BG-specific properties to astrocytes by controlling the expression of BG-specific genes, thereby ensuring proper differentiation of BGLPs into BGs.

developmental biology↗

Identification of genes supporting cold resistance of mammalian cells: lessons from a hibernator

Susceptibility of human cells to cold stress restricts the use of therapeutic hypothermia and long-term preservation of organs at low temperatures. In contrast, cells of mammalian hibernators possess remarkable cold resistance, but little is known about the molecular mechanisms underlying this phenomenon. In this study, we conducted a gain-of-function screening of genes that confer cold resistance to cold-vulnerable human cells using a cDNA library constructed from the Syrian hamster, a mammalian hibernator, and identified Gpx4 as a potent suppressor of cold-induced cell death. Additionally, genetic or pharmacological inhibition of Gpx4 in a hamster cell line under prolonged cold culture led to cell death, which resembles ferroptosis characterized by accumulation of lipid peroxide and ferrous iron dependency. Genetic disruption of other ferroptosis-suppressing pathways, namely biopterin synthesis and mitochondrial or plasma membrane CoQ reduction pathways, accelerated cold-induced cell death under Gpx4 dysfunction. Collectively, ferroptosis-suppressing pathways protect the cells of a mammalian hibernator from cold-induced cell death and the augmentation of these pathways renders cold resistance to cells of non-hibernators, including humans.

cell biology↗

Novel Thyroid-Specific Autoantibodies in Patients with Immune-Related Adverse Events Involving the Thyroid Gland

AimsProgrammed cell death-1 (PD-1) blockade therapy frequently results in immune-related adverse events involving the thyroid gland (thyroid irAEs). Although clinical features of thyroid irAEs are known, the mechanisms remain unclear. Here, we conducted a pilot study to investigate mechanisms of thyroid irAE development from the perspective of autoantibodies. MethodsWe performed immunoprecipitation-based assays using sera of 3 patients who developed thyroid irAEs with PD-1 blockade therapy by nivolumab and HEK293T cell lysates, including overexpressed proteins of interest (NKX2-1, PAX8, FOXE1, and HHEX; thyroid-specific transcriptional factors). The pellets were analyzed by western blot to detect the HiBit tag attached to the C-terminus of the proteins. ResultsRelevant changes to NKX2-1 bands were not seen in all 3 patients, but PAX8 bands were augmented in patient 2 with lung cancer and patient 3 with renal cell carcinoma. In addition, FOXE1 bands were augmented in patient 1 with malignant melanoma and patient 3, and a HHEX band was augmented in patient 3. Thus, we revealed novel thyroid-specific autoantibodies, PAX8Ab, FOXE1Ab, and HHEXAb. Expression patterns of the antigens recognized by these antibodies were not identical to the primary sites, so autoimmune responses in thyroid irAE may originate from the thyroid gland, and not the malignancy. Considering that TPOAb rather than TgAb is often negative in patients with thyroid irAEs, other mechanisms such as cytotoxic T cell and antigenicity of thyroglobulin may be involved. ConclusionsAlthough the significance of these novel autoantibodies needs further examination, the present study provides new insights for thyroid autoimmunity.

immunology↗

AUTS2 regulation of synapses for proper synaptic inputs and social communication.

Impairments in synapse development are thought to cause numerous psychiatric disorders. Autism susceptibility candidate 2 (AUTS2) gene has been associated with various psychiatric disorders, such as autism and intellectual disabilities. Although roles for AUTS2 in neuronal migration and neuritogenesis have been reported, its involvement in synapse regulation remains unclear. In this study, we found that excitatory synapses were specifically increased in the Auts2-deficient primary cultured neurons as well as Auts2 mutant forebrains. Electrophysiological recordings and immunostaining showed increases in excitatory synaptic inputs as well as c-fos expression in Auts2 mutant brains, suggesting that an altered balance of excitatory and inhibitory inputs enhances brain excitability. Auts2 mutant mice exhibited autistic-like behaviors including impairments in social interaction and altered vocal communication. Together, these findings suggest that AUTS2 regulates excitatory synapse number to coordinate E/I balance in the brain, whose impairment may underlie the pathology of psychiatric disorders in individuals with AUTS2 mutations.

neuroscience↗