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Katsura, K. A.

Publications and source records attributed to Katsura, K. A..

3 recordsLinked to original sources

A novel mouse model of rare neurodevelopmental disorder, TBCK Syndrome

TBCK Syndrome is a rare Mendelian disorder caused by variants in the TBCK gene. Although symptoms affect multiple organ systems, hallmark features include intellectual and developmental disability, craniofacial differences, hypotonia, and premature death. At the cellular level, TBCK has been implicated in mTOR signaling, autophagy, mitophagy, and mRNA trafficking; however, the mechanisms underlying disease onset and progression remain unclear. To address this gap, we characterized a mouse model of TBCK Syndrome. These mice lack exon 5 of the TBCK gene, resulting in a whole-body knockout of Tbck, modeling the most severe known variant. We performed a comprehensive battery of developmental assays, along with microcomputed tomography and histological analyses, which revealed systemic alterations consistent with those observed in affected individuals. Notably, phenotypic changes arising from Tbck loss emerge early and are detectable in the brain, indicating a primary neurodevelopmental origin of disease pathology. Rigorous characterization of this Tbck-deficient mouse establishes the first in vivo platform to investigate disease mechanisms and provides a foundation for preclinical evaluation of gene and targeted pharmacological therapy strategies. Summary StatementThis study establishes a rigorously validated animal model recapitulating systemic features of TBCK Syndrome, enabling targeted investigation of disease biology and preclinical assessment of candidate therapies.

genetics↗

Unique mineralization pattern revealed in TBCK syndrome mouse model

TBCK syndrome is a severe degenerative leukoencephalopathy with multisystem involvement. Neurodevelopmental, craniofacial, and pulmonary challenges are among the topmost effects on these children. TBCK has been implicated in endo-lysosomal regulation, RNA transport, and mTOR-associated pathways, all of which are critical for the development of mineralized tissue. Although craniofacial abnormalities can be clinically apparent, conventional imaging approaches may overlook subtle defects in mineral quality. Here, we apply our multimodal framework to investigate the mineralization of enamel, dentin, and alveolar bone in a Tbck knockout mouse model. This is the first time our multimodal framework will be applied to a genetic condition. Using micro-computed tomography (microCT), histology, nanoindentation, energy-dispersive spectroscopy, and Raman spectroscopy, we identify tissue- and stage-dependent mineral effects undetected by microCT alone. Tbck loss resulted in differences in enamel and dentin element compositions as early as secretory and transition stages, while mechanical properties remained undetected until maturation stage. Notably, Tbck knockout enamel exhibited reduced calcium and phosphorus content, along with increased carbon content during early mineralization, consistent with the retained organic matrix. Additionally, marked and opposing alterations in magnesium and iron levels began at the secretory stage. Together, these findings define a previously unrecognized mineralization signature associated with TBCK deficiency and establish multimodal hard-tissue analysis as a sensitive approach for detecting early craniofacial phenotypes in rare genetic disorders.

developmental biology↗

Multi-modal characterization of rodent tooth development

Craniofacial tissues undergo hard tissue development through mineralization and changes in physicochemical properties. This study investigates the mechanical and chemical properties of developing enamel, dentin, and bone in the mouse mandible. We employ a multi-modal, multi-scale analysis of the developing incisor and first molar at postnatal day 12 by integrating micro-computed tomography (microCT), nanoindentation (NI), energy dispersive spectroscopy (EDS), and Raman spectroscopy. Our findings demonstrate distinct patterns of mechanical, elemental, and chemical changes across mineralized tissues. These results suggest that mineral composition drives mechanical properties across different craniofacial hard tissues. Integrating multi-modal characterization of mineralized tissues opens new opportunities for investigating structure-function relationships in craniofacial biology and genetics.

developmental biology↗