Bailey, C. S. L. | bioRxiv Science

bioRxiv2023

LiverZap: A chemoptogenetic tool for global and locally restricted hepatocyte ablation to study cellular behaviours in liver regeneration

The liver restores its mass and architecture after injury. Yet, investigating morphogenetic cell behaviours and signals that repair tissue architecture at high spatiotemporal resolution remains challenging. We developed LiverZap, a tuneable chemoptogenetic liver injury model in zebrafish. LiverZap employs formation of a binary FAP-TAP photosensitiser followed by brief near-infrared illumination inducing hepatocyte-specific death and recapitulating mammalian liver injury types. The tool enables local hepatocyte ablation and extended live imaging of regenerative cell behaviours, critical for studying cellular interactions at the interface of healthy and damaged tissue. Applying LiverZap, we show that targeted hepatocyte ablation in a small region-of-interest is unexpectedly sufficient to trigger Liver Progenitor-like Cell (LPC)-mediated regeneration, challenging the current understanding of LPC activation. Associated dynamic bilary network rearrangement and E-cadherin relocalisation suggest modulation of cell adhesion as an integral step of LPC-mediated liver regeneration. This precisely targetable live cell ablation model will enable addressing of key regeneration paradigms.

cell biology↗

bioRxiv2019

The effect of Rosovitine on mPSM explants: a real time analysis

Previously we showed, using fixed tissue techniques, that treatment of chick embryos with a family of pharmacological inhibitors yields increased levels of NICD, an increased NICD half life and longer segments (Wiederman et al., 2015). Here we measure the effect of one of the pharmacological perturbations (Roscovtine) using a real time reporter of the somitogenesis clock. After processing the reporter signal using empirical mode decomposition, we measure the oscillator period in mPSM explants and find, in agreement with the previous study, that the period of the segmentation clock increases upon Roscovitine treatment. However, we also make the novel discovery that the differentiation rate of the mPSM tissue also increases upon Roscovitine treatment. Returning to the previous study, we find that the measured increases in somite size and oscillator period are only consistent with the clock and wavefront model if the wavefront velocity also increased.

developmental biology↗