Biology subjects

Ozeki, Y.

Publications and source records attributed to Ozeki, Y..

4 recordsLinked to original sources

bioRxiv2026

Adolescent prodromal phenotypes of psychiatric disorders: insights from a novel DISC1-perturbed monkey model

Neurodevelopmental deficits frequently lead to mild but significant adolescent social and cognitive changes, representing prodromal manifestations of adult-onset psychiatric disorders in a cross-disease manner. Although experimental medicine utilizes animal models to address the mechanisms, rodent brains lack critical structures for human higher brain functions such as the dorsolateral prefrontal cortex. To fill this translational gap, we generated monkeys with an impaired DISC1 gene locus, targeting the multifunctional protein essential for neurodevelopment and involved in transdiagnostic mental health risks. Here we analyze the F0 animals by minimizing mosaicism. At ages equivalent to human adolescence, these monkeys exhibited blunted responsiveness to social stimuli and increased internal drives, mirroring altered social behaviors in the prodromal stage in humans. Resting-state functional MRI data indicated disrupted global functional connectivity and reorganization of network topology, marked by a shift in the dominance of brain hubs from prefrontal regions to sensory areas. This primate model provides a unique platform for studying psychiatric disorders, such as schizophrenia, across the developmental trajectory.

neuroscience↗

bioRxiv2024

Functional genomics reveals the mechanism of hypoxic adaptation in nontuberculous mycobacteria

Mycobacterium intracellulare is a major etiological agent of the recently expanding Mycobacterium avium-intracellulare complex pulmonary disease (MAC-PD). Therapeutic regimens that include a combination of macrolides and antituberculous drugs have been implemented with limited success. To identify novel targets for drug development that accommodate the genomic diversity of M. avium-intracellulare, we subjected eight clinical MAC-PD isolates and the type strain ATCC13950 to genome-wide profiling to comprehensively identify universally essential functions by transposon sequencing (TnSeq). Among these strains, we identified 131 shared essential or growth-defect-associated genes by TnSeq. Unlike the type strain, the clinical strains showed increased requirements for genes involved in gluconeogenesis and the type VII secretion system under standard growth conditions, the same genes required for hypoxic pellicle-type biofilm formation in ATCC13950. Consistent with the central role of hypoxia in the evolution of M. intracellulare, the clinical MAC-PD strains showed more rapid adaptation to hypoxic growth than the type strain. Importantly, the increased requirements of hypoxic fitness genes were confirmed in a mouse lung infection model. These findings confirm the concordant genetic requirements under hypoxic conditions in vitro and hypoxia-related conditions in vivo, and highlight the importance of using clinical strains and host-relevant growth conditions to identify high-value targets for drug development.

microbiology↗

bioRxiv2022

Super-resolution vibrational imaging based on photoswitchable Raman probe

Super-resolution vibrational microscopy is a promising tool to increase the degree of multiplexing of nanometer-scale biological imaging, because the spectral linewidth of molecular vibration is about 50 times narrower than that of fluorescence. However, current techniques of super-resolution vibrational microscopy still suffer from various limitations including the need for cell fixation, high power loading or complicated frequency-modulated detection schemes. Herein we utilize photoswitchable stimulated Raman scattering (SRS) to develop a method that we call reversible saturable optical Raman transitions (RESORT) microscopy, which overcomes these limitations. We first describe a new kind of photoswitchable Raman probe designated DAE620 and then we employ a standard SRS detection scheme to validate its signal activation and depletion characteristics when exposed to low-power (microwatt level) continuous-wave laser light. By harnessing the SRS signal depletion of DAE620 through a donut-shaped beam, we demonstrate super-resolution vibrational imaging of mammalian cells with excellent chemical specificity and spatial resolution beyond the optical diffraction limit. Our results indicate RESORT microscopy to be an effective tool with high potential for multiplexed super-resolution imaging of live cells.

bioengineering↗

bioRxiv2020

Virtual-freezing fluorescence imaging flow cytometry

By virtue of the combined merits of flow cytometry and fluorescence microscopy, imaging flow cytometry (IFC) has become an established tool for cell analysis in diverse biomedical fields such as cancer biology, microbiology, immunology, hematology, and stem cell biology. However, the performance and utility of IFC are severely limited by the fundamental trade-off between throughput, sensitivity, and spatial resolution. For example, at high flow speed (i.e., high throughput), the integration time of the image sensor becomes short, resulting in reduced sensitivity or pixel resolution. Here we present an optomechanical imaging method that overcomes the trade-off by virtually "freezing" the motion of flowing cells on the image sensor to effectively achieve 1,000 times longer exposure time for microscopy-grade fluorescence image acquisition. Consequently, it enables high-throughput IFC of single cells at >10,000 cells/s without sacrificing sensitivity and spatial resolution. The availability of numerous information-rich fluorescence cell images allows high-dimensional statistical analysis and accurate classification with deep learning, as evidenced by our demonstration of unique applications in hematology and microbiology.

cell biology↗