ATP7B gene therapy of autologous reprogrammed hepatocytes alleviates copper accumulation in a mouse model of Wilson's disease

Background and aims: Wilson's disease (WD) is a rare hereditary disorder due to ATP7B gene mutation, causing pathologic copper storage mainly in the liver and neurological systems. Hepatocyte transplantation showed therapeutic potential; however, this strategy is often hindered by a shortage of quality donor cells and by allogeneic immune rejection. In this study, we aimed to evaluate the function and efficacy of autologous reprogrammed, ATP7B gene-restored hepatocytes using a mouse model of WD.

Approach and results: Sufficient liver progenitor cells (LPCs) were harvested by reprogramming hepatocytes from ATP7B^-/- mice with small molecules, which exhibited strong proliferation and hepatic differentiation capacity in vitro. After lentivirus-mediated mini ATP7B gene transfection and redifferentiation, functional LPC-ATP7B-derived hepatocytes (LPC-ATP7B-Heps) were developed. RNA Sequencing data showed that, compared with LPC-green fluorescent protein-Heps (LPC-GFP-Heps) with enrichment of genes that were mainly in pathways of oxidative stress and cell Apoptosis, in LPC-ATP7B-Heps under high copper stress, copper ion binding and cell proliferation pathways were enriched. LPC-ATP7B-Heps transplantation into ATP7B^-/- mice alleviated deposition of excess liver copper with its associated inflammation and fibrosis, comparable with those observed using normal primary hepatocytes at 4 months after transplantation.

Conclusions: We established a system of autologous reprogrammed WD hepatocytes and achieved ATP7B gene therapy in vitro. LPC-ATP7B-Heps transplantation demonstrated therapeutic efficacy on copper homeostasis in a mouse model of WD.