CRISPR‐Cas9 Gene Editing Yields a Novel Rat Model of Cardiometabolic Disease

Abstract

Despite strong evidence that the Metabolic Syndrome (MetS) and its defining features (central obesity, dyslipidemia, hypertension, hyperglycemia) are highly heritable, the genetic etiology is complex and relatively few causative genes are known. For this reason, we employ the Lyon Hypertensive (LH) rat, a well‐characterized polygenic inbred MetS model. Previous genetic and computational approaches identified a novel gene (C17h6orf52) as a putative master regulator of gene expression and oxidative phosphorylation with pleiotropic effects on body weight and blood pressure regulation.In this study, two different frameshift mutations were generated independently by CRISPR‐Cas9 gene editing, producing either a 5 base pair deletion or a 10 base pair insertion in exon 2 of C17h6orf52, and females from the resulting mutant rat strains, designated M1 and M2, respectively, were characterized (Table 1). Herein, mutations in C17h6orf52 are shown to significantly increase blood pressure and serum cholesterol in vivo, despite no significant changes in body composition or body weight in LH‐derived female rats.Either mutation appears to cause modest, but significant or nearly significant, increases in blood pressure on a 0.3% NaCl diet. M1−/− females exhibit significantly increased systolic and diastolic blood pressure, while M2−/− females' systolic and diastolic blood pressure is more moderately elevated. This effect is potentiated when animals are administered a high salt diet. Finally, although neither total nor low‐density lipoprotein (LDL) cholesterol is changed in the M1 female rats with respect to their wildtype control, M2 females develop higher serum cholesterol, as well as significantly higher LDL cholesterol.The differences in phenotype between the M1 and M2 mutations were unexpected. Preliminary data indicates that 5 base pair deletion present in the M1−/− rats results in two distinct splicing variants that may be contributing to the observed phenotype differences. Nevertheless, these data suggest that C17h6orf52 is protective against cardiometabolic risk factors, given that C17h6orf52 mRNA is more highly expressed in MetS‐susceptible LH rats than MetS resistant Lyon Normotensive (LN) rats, and the mutation confers a greater burden of MetS features on an already obese and hypertensive rat. The continued study of this rat model of Metabolic Syndrome has the potential to functionally validate an uncharacterized regulatory gene, and provide novel targets for pharmacological intervention in the treatment of obesity.Support or Funding InformationR01HL089895, R21DK089417, T32GM008629, 14GRNT20410043This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.