Loss of canonical splicing factor SRSF1 in hepatocytes results in acute liver injury and regeneration

Post-transcriptional gene regulatory mechanisms (PTGRM) contribute profoundly to liver development and physiology. Alternative splicing is one of the earliest mechanisms of gene regulation acting on nascently transcribed mRNA. This process is mediated by a large class of proteins known as splicing factors. SRSF1 is a canonical splicing factor with roles in both constitutive and alternative splicing. While its biochemical activities have been studied extensively, its role in tissue physiology are not well defined. In this study we investigate the role of SRSF1 in liver physiology using hepatocyte-specific knock-out mice models. Hepatocyte-specific knock-out of SRSF1 was achieved in two ways; 1) SRSF1 floxed mice were crossed with AlbCre transgenic mice and 2) SRSF1 floxed mice were injected with AAV8-TBG-iCre viral vector. The latter model allowed for investigating acute changes in hepatocyte upon ablation of SRSF1. Both models exhibit acute liver injury with severe cellular damage, inflammation and lipid accumulation. Utilizing high-throughput transcriptome profiling on purified hepatocytes, we find acute loss of SRSF1 triggers activation of the p53 pathway and splicing dysregulation of genes involved in mRNA metabolism. Continuous hepatic injury in this model eventually triggers a regenerative response resulting in the upregulation of genes involved in proliferation and repopulation of the tissue parenchyma.