Figure 6.

NADPH oxidase 4 (Nox4) mediates gadolinium-induced renal fibrosis. A: gadolinium concentrations from the flash-frozen renal cortex. Inductively coupled plasma mass spectroscopy was performed. B: Nox4 deficiency abrogated gadolinium-based contrast agent-induced renal pathology. Top, gadolinium-based contrast agent treatment induced mesangial expansion, glomerulomegaly, and an increase in interstitial cellularity (cyan arrow). Periodic acid-Schiff (PAS) staining was performed. Middle, fibronectin. Immunohistochemistry was performed. Bottom, collagen type IV. Immunohistochemistry was performed. Calibration bars = 0.05 mm. C: deficiency of Nox4-abrogated gadolinium-induced renal cortical reactive oxygen species. Confocal microscopy was performed. DHE, dihydroethidium. Overall magnification: ×200. D: gadolinium-based contrast agent-induced renal fibronectin accumulation was abrogated by the absence of Nox4. Immunoblot analysis was peformed. The accompanying bar chart depicts the pixel densities of fibronectin relative to the loading control, GAPDH. Analysis of variance and Tukey honestly significant difference by post hoc testing (***P < 0.001 from first lane, ###P < 0.001 from second lane, †††P < 0.001 from third lane, respectively).