Figure 4. Genetic ablation of COUP‐TFII in adult mice attenuates injury‐induced kidney fibrosis.
- Strategy of conditional knockdown of COUP‐TFII in adult mice. A LacZ knock‐in allele is inserted into the genomic COUP‐TFII locus after the second LoxP site.
- Activation of Cre recombinase by tamoxifen (TAM) results in COUP‐TFII deletion and the expression of LacZ reporter (detected by immunostaining of β‐galactosidase (β‐Gal, red) in the UUO mice model (n = 2). Quantification of mean of 8–10 confocal images at 200× hpf. **P < 0.01; ***P < 0.001 by paired t‐test; mean ± SD.
- Using heterozygous mice (F/+; Cre/+), β‐Gal+ cells (red) increased after TAM injection in UUO kidneys, and co‐localized with COUP‐TFII+ cells (green; n = 3).
- COUP‐TFII+ cells decreased significantly in the UUO kidney in TAM‐treated homozygous (F/F;Cre/+) mice (KO group, n = 6) compared with wild‐type littermates (WT group, n = 4). Expression of αSMA (red) and collagen 1 (yellow) are also markedly reduced. Masson Trichrome staining shows less kidney fibrosis in KO compared with WT group. Quantification of mean of 8–10 confocal images per animal at 200× hpf. **P < 0.01 by unpaired t‐test, mean ± SD.