Abstract—Renal dopamine 2 receptor dysfunction is associated with oxidative stress and high blood pressure (BP). We have
reported that DJ-1, an oxidative stress response protein, is positively regulated by dopamine 2 receptor in the kidney.
The transcription factor nuclear factor erythroid 2–related factor 2 (Nrf2) regulates the expression of several antioxidant
genes. We tested the hypothesis that Nrf2 is involved in the renal DJ-1–mediated inhibition of reactive oxygen species
production. We have reported that silencing dopamine 2 receptor in mouse renal proximal tubule cells decreases the
expression of DJ-1. We now report that silencing DJ-1 or dopamine 2 receptor in mouse proximal tubule cells and mouse
kidneys decreases Nrf2 expression and activity and increases reactive oxygen species production; BP is also increased
in mice in which renal DJ-1 or dopamine 2 receptor is silenced. DJ-1−/− mice have decreased renal Nrf2 expression
and activity and increased nitro-tyrosine levels and BP. Silencing Nrf2 in mouse proximal tubule cells does not alter
the expression of DJ-1 or dopamine 2 receptor, indicating that Nrf2 is downstream of dopamine 2 receptor and DJ-1.
An Nrf2 inducer, bardoxolone, normalizes the systolic BP and renal malondialdehyde levels in DJ-1−/− mice without
affecting them in their wild-type littermates. Because Nrf2 ubiquitination is increased in DJ-1−/− mice, we conclude that
the protective effect of DJ-1 on renal oxidative stress is mediated, in part, by preventing Nrf2 degradation