MIER1-FLAG ChIP-seq Analysis in Liver at 0 h and 24 h after 70% Partial Hepatectomy

To explore how Mier1 influence liver regeneration, we performed chromatin immunoprecipitation followed by sequencing in liver tissues at 0 h and 24 h after 70% partial hepatectomy (PHx). Due to a lack of available MIER1 antibody for ChIP-seq analysis, exogenous liver expression of MIER1-FLAG under TBG promoter was executed using AAV vectors, and ChIP-seq was conducted using FLAG antibody. Liver tissues from animals receiving empty vectors were also collected for ChIP-seq with FLAG antibody as negative control to remove possible non-specific binding signals from FLAG antibody. We observed in total 9310 sites bound by MIER1 in total, with a majority of these binding sites around the transcription start sites or present in introns or exons. Further analysis combining the results from RNA-seq revealed a significant set of genes involved in cell cycle, DNA replication and chromosome organization, that were bound by MIER1 and upregulated after MIER1 loss in liver tissues 24 hours after surgery, indicating a direct functional regulation of these genes via MIER1. Overall design: For the ChIP-seq analysis, chromatin was prepared from 3 biological replicates of animals in each group. Exogenous liver expression of a MIER1-FLAG under a liver-specific TBG promoter was executed using AAV vectors (AAV-MIER1-FLAG) and ChIP-seq was conducted using FLAG antibody. Liver tissues infected with AAV-LUCIFERASE viruses were used as control. Liver tissues were collected for analysis at 0 h and 24 h after 70% partial hepatectomy.