Targeted disruption of CTCF binding near the Ren gene alters gene expression and plasma renin activity in response to dietary salt

• Published in: Physiology (Bethesda, Md.) Md.), 2023-05, Vol.38 (S1)
• Main Authors: Vanden Avond, Mark, Grzybowksi, Michael, Kurth, Theresa, Greene, Andrew, Liang, Mingyu, Cowley, Allen, Geurts, Aron
• Format: Article
• Language: English
• ISSN: 1548-9213; 1548-9221
• DOI: 10.1152/physiol.2023.38.S1.5732569

Abstract only Hypertension is the leading risk factor for cardiovascular disease and impacts one in three adults globally. One genetic mechanism that may affect blood pressure regulation and alter hypertension risk in the general population is the disruption of chromatin conformation by common genetic variation. CCCTCF-binding factor (CTCF) has many important functions including regulating the conformation of chromatin by binding to specific DNA sequences and can thereby alter gene expression. The renin locus has multiple CTCF motifs surrounding the renin gene and cellular expression of CTCF is critical for proper renin expression. Despite these important functions, the role that local chromatin conformation plays to regulate normal renin expression including its response to stimuli such as dietary salt intake and in the downstream regulation of blood pressure is unknown. We hypothesize that disruption of local chromatin conformation can alter gene expression, intermediate physiological mechanisms, and blood pressure. A mutant rat model was created using CRISPR-Cas9 in the genetic background of the Dahl salt-sensitive (SS) rat with a disruption to the CTCF binding motif located within an intron of Golt1a near the Ren gene which we have previously demonstrated an interaction with the renin proximal promoter. Here we report the preliminary characterization of this model for renin expression and plasma renin activity (PRA). Chromatin immunoprecipitation-qPCR showed a reduction in CTCF binding at the Golt1a locus in our mutant model compared to wild-type (WT), confirming our mutation resulted in a disruption in CTCF binding in vivo. An expected reduction (p