A cell atlas of the regenerating human liver after portal vein embolization
In this work, we applied single-cell transcriptome sequencing on primary human liver tissue samples to study cellular processes underlying human liver regeneration. In order to study regeneration-specific cellular processes we obtained primary healthy liver tissue samples and liver tissue samples from patients that underwent a preoperative medical procedure called portal vein embolization (PVE). This medical treatment is performed to enlarge part of the liver such that a diseased portion can be removed avoiding liver insufficiency and thus we used post-PVE-derived tissues as a model to study liver regeneration in humans. This paradigm enabled us to catalog cell states related to tissue structure in two important and physiologically relevant conditions: hypertrophy and atrophy. In addition, we overcame technical challenges and provided novel protocols and pipelines for generating high quality liver cell atlases from frozen specimens showing consistency in results between fresh and frozen tissue datasets. Moreover, we established tissue-scale iterative indirect immunofluorescence imaging to enable high-dimensional spatial analysis of perivascular microenvironments and uncover cellular and histological alterations to regenerating liver lobules.