Biology subjects

Isono, M.

Publications and source records attributed to Isono, M..

2 recordsLinked to original sources

bioRxiv2025

Lipids Are Involved in Heterochromatin Condensation: A Quantitative Raman and Brillouin Microscopy Study

Chromatin, a fundamental component of eukaryotic genomes, is categorized into euchromatin and heterochromatin, which play distinct roles in gene regulation. Although these two chromatin states are distinguished by their degree of condensation, quantitatively measuring the degree of chromatin condensation, as well as the physical properties of chromatin in living cells, remains challenging. In this study, label-free in situ quantitative imaging was performed using a Raman-Brillouin microscope to visualize the spatial distribution of molecular concentration and viscoelasticity within the nuclear environment of a living cell. A quantitative concentration distribution image of each intracellular biomolecule was obtained by combining Raman imaging with multivariate curve resolution analysis, using a water Raman band as an internal standard. Simultaneous Raman-Brillouin imaging enables the quantitative visualization of viscoelasticity within a cell. Using this approach, we found that, in addition to DNA, heterochromatin is enriched in lipids and that lipids play a critical role in heterochromatin formation, determining its mechanical properties. These findings provide new insights into the mechanism of heterochromatin formation and its chemical and physical properties, leading to a comprehensive understanding of gene regulation and nuclear organization.

biophysics↗

bioRxiv2022

Single-nucleus ATAC-seq elucidates major modules of gene regulation in the development of non-alcoholic fatty liver disease

We investigated the progression of non-alcoholic fatty liver disease (NAFLD) from fatty liver to steatohepatitis using single-nucleus and bulk ATAC-seq on the livers of rats fed a high-fat diet (HFD). Rats fed HFD for 4 weeks developed fatty liver, and those fed HFD for 8 weeks further progressed to steatohepatitis. We observed an increase in the proportion of inflammatory macrophages, consistent with the pathological progression. Utilizing machine learning, we divided global gene regulation into modules, wherein transcription factors within a module could regulate genes within the same module, reaffirming known regulatory relationships between transcription factors and biological processes. We identified core genes--central to co-expression and protein-protein interaction--for the biological processes discovered. Notably, a large part of the core genes overlapped with genes previously implicated in NAFLD. Single-nucleus ATAC-seq, combined with data-driven statistical analysis, offers insight into in vivo global gene regulation as a combination of modules and assists in identifying core genes of relevant biological processes. Summary blurbThis study uncovers cell type-specific global gene regulation in NAFLD progression, identifying core genes and shedding light on the diseases molecular mechanisms.

genomics↗