SAT017 Investigating The Spatial Regulation Mediated By Constitutive Androstane Receptor

Disclosure: A. Asokakumar: None. S. Anakk: None. Xenobiotic nuclear receptor, Constitutive Androstane Receptor (CAR/NR1i3), is extensively studied in the liver for its detoxification functions. In addition, CAR is also involved in controlling metabolic processes, protein synthesis, immune functions, and cellular proliferation. We examined if CAR achieves these wide ranges of functions by the spatial distribution of labor within the liver. Although previous studies have shown that CAR transcriptionally regulates many genes involved in these pathways, their spatial control is yet to be examined. For instance, the liver is divided into three zones (pericentral, periportal and midzonal) and whether CAR is expressed equally in these zones remains unknown. However, CAR has not been studied at the protein levels due to the lack of reliable antibody. We generated a Flag-tagged CAR mouse model using CRISPR Cas that will enable us to investigate CAR protein expression, localization and its interactions with other proteins. The transgenic FLAG-CAR model will also allow us to monitor its transition between the cytoplasm and nucleus or between different liver zones upon activation. Further, we have generated single-cell RNA sequencing data from individual liver cells in both sexes of WT mice with and without CAR activation. We classified the hepatocytes, the major liver cell population, into different zones based on known biomarkers. Currently, we are investigating if these hepatocytes from different zone activate different CAR target genes. Our initial analysis revealed that CAR target genes are highly expressed in the central and midzonal regions. Next, we will examine the CAR target genes expression in different liver zones based on their functions. In the future, we aim to visualize the CAR protein and its target protein expression based on zonation. Overall, this study will help us to understand CAR localization and its target regulation both at transcriptional and translational levels. Presentation: Saturday, June 17, 2023