Abstract
ABSTRACTHypertension (HTN) involves genetic variability in the renin-angiotensin system and characterizing this variability will help advance precision antihypertensive treatments. We previously reported that angiotensinogen (AGT) mRNA is endogenously bound by mir-122-5p and that rs699 A>G significantly decreases reporter mRNA in the functional mirSNP assay PASSPORT-seq. TheAGTpromoter variant rs5051 C>T is in linkage disequilibrium (LD) with rs699 A>G and increasesAGTtranscription. We hypothesized that the increasedAGTby rs5051 C>T counterbalancesAGTdecrease by rs699 A>G, and when these variants occur independently, would translate to HTN-related phenotypes. The independent effect of each of these variants is understudied due to their LD, therefore, we usedin silico, in vitro, in vivo, and retrospective clinical and biobank analyses to assess HTN andAGTexpression phenotypes where rs699 A>G occurs independently from rs5051 C>T.In silico, rs699 A>G is predicted to increase mir-122-5p binding strength by 3%. Mir-eCLIP assay results show that rs699 is 40-45 nucleotides from the strongest microRNA binding site in theAGTmRNA. Unexpectedly, rs699 A>G increasesAGTmRNA in a plasmid cDNA HepG2 expression model. GTEx and UK Biobank analyses demonstrate that liverAGTexpression and HTN phenotypes were not different when rs699 A>G occurs independently from rs5051 C>T, allowing us to reject the original hypothesis. However, both GTEx and ourin vitroexperiments suggest rs699 A>G confers cell-type specific effects onAGTmRNA abundance. We found that rs5051 C>T and rs699 A>G significantly associate with systolic blood pressure in Black participants in the UK Biobank, demonstrating a 4-fold larger effect than in White participants. Further studies are warranted to determine if the altered antihypertensive response in Black individuals might be due to rs5051 C>T or rs699 A>G. Studies like this will help clinicians move beyond the use of race as a surrogate for genotype.
Publisher
Cold Spring Harbor Laboratory