NF-κB Inhibition Ameliorates Angiotensin II–Induced Inflammatory Damage in Rats

Abstract —We recently reported that the activation of nuclear factor-κB (NF-κB) promotes inflammation in rats harboring both human renin and angiotensinogen genes (double-transgenic rats [dTGR]). We tested the hypothesis that the antioxidant pyrrolidine dithiocarbamate (PDTC) inhibits NF-κB and ameliorates renal and cardiac end-organ damage. dTGR feature hypertension, severe renal and cardiac damage, and a 40% mortality rate at 7 weeks. Electrophoretic mobility shift assay showed increased NF-κB DNA binding activity in hearts and kidneys of dTGR. Chronic PDTC (200 mg/kg SC) treatment decreased blood pressure (162±8 versus 190±7 mm Hg; P =0.02) in dTGR compared with dTGR controls. The cardiac hypertrophy index was also significantly reduced (4.90±0.1 versus 5.77±0.1 mg/g; P 95% (2.5±0.8 versus 57.1±8.7 mg/d; P fos and c- jun mRNA expression. PDTC treatment reduced c- fos but not c- jun mRNA. Immunohistochemistry showed increased p65 NF-κB subunit expression in the endothelium and smooth muscle cells of damaged small vessels, as well as infiltrating cells in glomeruli, tubules, and collecting ducts of dTGR. PDTC markedly reduced the immunoreactivity of p65. PDTC also prevented the NF-κB–dependent transactivation of the intercellular adhesion molecule ICAM-1 and inducible nitric oxide synthase. Monocyte infiltration was markedly increased in dTGR kidneys and hearts. Chronic treatment reduced monocyte/macrophage infiltration by 72% and 64%, respectively. Thus, these results demonstrate that PDTC inhibits NF-κB activity, ameliorates inflammation, and protects against angiotensin II-induced end-organ damage.