Understanding the molecular basis of the regenerative response following hepatic injury holds promise for improved treatments of liver diseases. Here, we report an innovative method to profile gene expression specifically in the hepatocytes that regenerate the liver following toxic injury. We utilize the Fah–/– mouse, a model of hereditary tyrosinemia, which conditionally undergoes severe liver injury unless fumarylacetoacetate hydrolase (FAH) expression is reconstituted ectopically. We employ translating ribosome affinity purification followed by high-throughput RNA sequencing (TRAP-seq) to isolate mRNAs specific to repopulating hepatocytes. We uncover novel upstream regulators and important signaling pathways to be highly enriched in genes changed in regenerating hepatocytes. Specifically, we identify glutathione metabolism — particularly the gene Slc7a11 encoding the cystine/glutamate antiporter (xCT) — to be massively upregulated during liver regeneration. Furthermore, we show that Slc7a11 overexpression in hepatocytes enhances, and its suppression inhibits, repopulation following toxic injury. TRAP-seq allows cell type-specific expression profiling in repopulating hepatocytes and suggests xCT as a potential therapeutic target for supporting antioxidant responses during liver regeneration.
Amber W. Wang, Kirk J. Wangensteen, Yue J. Wang, Adam M. Zahm, Nicholas G. Moss, Noam Erez, Klaus H. Kaestner