Abstract P086: Superoxide but Not Hydrogen Peroxide Increases Nuclear Translocation of Transcription Factor Sp3 and AT1 Receptor Expression in the Renal Cells [Session Title: Poster Session 1- Trainee Onsite Poster Competition and Reception]

Age-associated oxidative stress causes up-regulation of renal AT1 receptor function (AT1R) and hypertension in aging Fischer Brown Norway (FBN) rats. Here we studied the mechanism of up-regulation of renal AT1R, and further tested superoxide Vs hydrogen peroxide (H2O2) specificity in this phenomenon. We found that transcription factor Sp3 plasmid increased (Control vs Sp3: 0.1165 ± 0.01 vs 0.3810 ± 0.03) while Sp3 siRNA decreased (Control siRNA vs Sp3 siRNA: 1.11 ± 0.25 vs 0.64 ± 0.06) the levels of AT1 receptor protein in human kidney (HK2) cells. Whereas transcription factor NF-kB p-65 plasmid did not affect AT1 receptor protein levels in these cells (Control vs NF-kB: 0.25 ± 0.025 vs 0.31 ± 0.035). DDC, a superoxide prodrug, but not H2O2 treatments increased nuclear levels of Sp3 and NF-kB proteins in HK2 cells [(Control vs DDC, vs H2O2,vs H2O2 + tempol): Sp3 (0.50 ± 0.08 vs 1.28 ± 0.21 vs 0.68 ± 0.14 vs 1.04 ± 0.30 densities); NF-kB (0.4025 ± 0.13 vs 1.808 ± 0.54 vs 0.4950 ± 0.15 vs 0.6375 vs ± 0.18 densities)]. Tempol treatment, a superoxide scavenger, attenuated DDC-mediated nuclear accumulation of Sp3 (DDC vs DDC + tempol: 1.28 ± 0.21 vs 0.52 ± 0.12 densities) and NF-kB (DDC vs DDC + tempol: 1.808 ± .54 vs 0.43 ± 0.18 densities]. In addition, DDC but not H2O2 increased AT1 receptor mRNA expression, measured by RT-qPCR [(Control vs DDC, vs H2O2):...
Source: Hypertension - Category: Cardiology Authors: Tags: Session Title: Poster Session 1- Trainee Onsite Poster Competition and Reception Source Type: research