Figure 2.

Epoxyeicosatrienoic acid (EET) administration or pharmacological inhibition of soluble epoxide hydrolase attenuates renal interstitial fibrogenesis during unilateral ureteral obstruction (UUO). Male C57BL/6 mice were subjected to either UUO or sham operation and then administered with the combination of 11,12-EET + 14,15-EET (15 µg/kg/day, using an osmotic pump) for 7 days. For the pharmacological inhibition of soluble epoxide hydrolase, t-TUCB (0.4 mg/mouse/day) or vehicle was administered by oral gavage beginning 24 h before UUO. The kidneys were harvested at 7 days after the operation. A: kidney sections were subjected to Sirius red staining and immunohistochemical staining using anti-collagen type I (Col I; brown) and anti-α-smooth muscle actin (α-SMA) antibodies. Hematoxylin stain (blue color) was used for counterstaining. Pictures of the cortex were taken. Scale bars = 50 μm. B: kidneys were subjected to Western blot analysis using anti-α-SMA antibody. GAPDH was used as a loading control. Band density was measured using ImageJ software. C: mRNAs were extracted from kidney tissues using RNA extraction solution as described in materials and methods. The mRNA level of transforming growth factor (TGF)-β was measured and normalized using the GAPDH level. Data are presented as means ± SD; n = 6. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001. One-way or two-way ANOVA followed by a Tukey’s post hoc multiple comparison test was used to determine significance. t-TUCB, 4-[[trans-4-[[[[4-(trifluoromethoxy)phenyl]amino]carbonyl]amino]cyclohexyl]oxy]benzoic acid.