Temporal dynamics of metabolic acquisition in grafted engineered human liver tissue

Abstract

Liver disease affects millions globally and end-stage liver failure is only cured by organ transplant. Unfortunately, there is a growing shortage of donor organs and disparities in equitable access to transplants among different populations. Less than 10% of global transplantation needs are currently met, highlighting the demand for alternative therapies. Engineered liver tissue grafts that supplement organ function could address these demands. While engineered liver tissues built from human hepatocytes, endothelial cells, and fibroblasts encased in hydrogel have been successfully engrafted in rodent models previously, the extent to which these tissues express human liver metabolic genes and proteins remains unknown. Here, we built engineered human liver tissues and characterized their engraftment, expansion, and metabolic phenotype at sequential stages post-implantation by RNA sequencing, histology, and host serology. Expression of metabolic genes was observed at weeks 1-2, followed by cellular organization into hepatic cords by weeks 4-9.5. Furthermore, grafted engineered tissues exhibited progressive spatially restricted expression of critical functional proteins known to be zonated in the native human liver. To our knowledge, this is the first report of engineered human liver tissue zonation after implantation in vivo, which could have important translational implications for this field.