Abstract 19164: The Role of Klf6 in Hypertensive Inflammation

Abstract

Salt-sensitivity of blood pressure (SSBP) is a major risk factor for cardiovascular morbidity and mortality in people with or without hypertension. We previously found that oxidative lipid protein modification via NADPH oxidase in antigen presenting cells (APCs) contributes to SSBP but the underlying mechanisms are not known. HIF1α, which codes glycolytic enzymes in APCs enhances expression of Kruppel like factor 6 (KLF6), promoting expression of PDGFB which binds to the PDGFB receptor to activate NADPH oxidase, leading to increased oxidative stress and activation of mTOR. We hypothesize that HIF2α contributes to SSBP through activating NADPH oxidase by enhancing KLF6. To test this hypothesis, we isolated monocytes from human participants (N =11) and treated them with either high (190 mMol/L) or normal (150 mMol/L) Na+ in vitro for 72 hours and subsequently performed bulk RNA sequencing. We found that elevated sodium increases expression of HIFα (16437 ± 1810 vs. 42233 ± 6282, p = 2.28E-05) and KLF6 (9058 ± 584.3 vs. 12817 ± 1108, p = 0.6768). Interestingly, while the PDGFB receptor was upregulated by elevated sodium ( 21.18 ± 4.600 vs. 566.3 ± 205.3, p = 3.91E-13), the ligand PDGFB was downregulated (1249 ± 215.9 vs. 610.5 ± 118.2, p = 6.11E-04). In additional experiments, we performed single cell transcriptomic analysis in on immune cells of people phenotyped for SSBP. We found that in monocytes, as salt goes up with blood pressure so does the expression of KLF6 (r = 0.3773, p = 0.3561), PDGFB (r = 0.5604, p = 0.1485), and PDGFB receptor (r = 0.4436, p = 0.2709). Our data demonstrate the HIF1α-KLF6 pathway contributes to inflammation and SSBP.