Biology subjects

Janusauskas, J.

Publications and source records attributed to Janusauskas, J..

3 recordsLinked to original sources

bioRxiv2025

Organotypic Timelapse recording with Transcriptomic Readout (OTTR) links cell behaviour to cell identity in human tissues

Linking dynamic cellular behaviour to molecular states in intact human tissue remains challenging because during live imaging only limited molecular information can be captured while high-dimensional molecular measurements are destructive. Here we describe Organotypic Timelapse recording with Transcriptomic Readout (OTTR), which integrates week-long live imaging of sparsely labelled organotypic slice cultures with highly multiplexed in situ spatial transcriptomics. We applied OTTR to primary human glioblastoma and fetal cortical tissues. Using sparse labelling, we tracked the migration, proliferation, and lineage of tens of thousands of individual cells per sample. Following live imaging, precision resectioning and alignment allowed us to perform spatial transcriptomics on the very same tissue, thereby preserving the link between dynamic cell behaviours and transcriptomic states. We used OTTR to quantify cell-type specific migration patterns, lineage trees and the behaviour of cells near vasculature. OTTR provides a powerful, broadly applicable method for investigating the complex interplay between cell behaviour and molecular state in human tissues.

molecular biology↗

bioRxiv2023

Glioblastoma is spatially organized by neurodevelopmental programs and a glial-like wound healing response

Glioblastoma is the deadliest brain cancer, characterized by large cellular diversity whose complexity and organizing principles are only starting to be uncovered. Both neurodevelopment-like and mesenchymal-like cell states have been described in glioblastoma1-8, with the latter being strongly implicated in malignancy and disease progression8-11. However, the nature of these mesenchymal-like cell states remains unresolved. Here, we performed deep single-cell RNA sequencing of rare glioblastoma cases where tissue could be sampled from tumor core to macroscopically normal cortex. We discovered that previously defined mesenchymal-like tumor cell states instead represented a wound response that was shared across both malignant and non-malignant cell types and was spatially confined to the tumor bulk. Using glioblastoma organoids, we showed that the wound response transcriptional state could be reversibly induced in vitro by hypoxia and human plasma. We used multiplex single-molecule spatial transcriptomics12 on a large patient cohort to show that the activation of wound response states was associated with hypoxia, and organized by distance to perivascular niches. Our findings help reconceptualize the cellular landscape of glioblastoma, wherein a reactive wound-response tissue state shared by all cells in the tumor bulk is superimposed on a fundamentally neurodevelopmental and glial tumor.

cancer biology↗

bioRxiv2022

Scalable in situ single-cell profiling by electrophoretic capture of mRNA

Methods to spatially profile the transcriptome are dominated by a trade-off between resolution and throughput. Here, we developed a method named EEL FISH that can rapidly process large tissue samples without compromising spatial resolution. By electrophoretically transferring RNA from a tissue section onto a capture surface, EEL speeds up data acquisition by reducing the amount of imaging needed, while ensuring that RNA molecules move straight down towards the surface, preserving single-cell resolution. We applied EEL on eight entire sagittal sections of the mouse brain and measured the expression patterns of up to 440 genes to reveal complex tissue organisation. Moreover, EEL enabled the study of challenging human samples by removing autofluorescent lipofuscin, so that we could study the spatial transcriptome of the human visual cortex. We provide full hardware specification, all protocols and complete software for instrument control, image processing, data analysis and visualization.

neuroscience↗