Effect of gp91phox ds-tat (NOX2 inhibitor [NOX2-I]) on lung NOX2 complex assembly and inflammation after intraperitoneal LPS injection. Six-day-old NOX2+/+ mouse pups were pretreated with intraperitoneal NOX2-I (10 mg/kg) 2 hours before intraperitoneal injection of LPS or saline. (A and B) Homogenized lung lysates obtained 6 hours after intraperitoneal LPS or saline injection were immunoprecipitated for gp91phox, followed by Western blotting for p67phox and gp91phox (A), analysis by densitometry shown (B). *P < 0.01 (control versus i.p. LPS); #P = 0.01 (i.p. LPS versus NOX2-I + i.p. LPS) (n ≥ 4). (C) Homogenized lung lysates were used to quantify TNF-α, KC, and IL-1β mRNA expression by real-time polymerase chain reaction 24 hours after intraperitoneal injection of NOX2-I. *P < 0.01 (control versus i.p. LPS); #P < 0.05 (i.p. LPS versus NOX2-I + i.p. LPS) (n ≥ 4). (D and E) Twenty-four hours after intraperitoneal injection of LPS or saline, mouse pup lungs were homogenized, and the clarified lysates were immunoblotted for ICAM-1 (D); densitometric quantification shown graphically (E). *P < 0.01 (control versus i.p. LPS); #P < 0.05 (i.p. LPS versus NOX2-I + i.p. LPS) (n ≥ 4). ANOVA with post hoc tests was used for analysis of data.