Podocyte Quantification via WT1 Immunohistochemistry

Wilms tumor type 1 (WT1), a transcription factor, encodes a zinc finger protein that is associated with the development of renal failure, and located in podocyte nuclei, and is identified as a highly expressed specific marker in mature podocytes [31 (link)]. The podocyte number was estimated by staining WT1 in renal samples with immunohistochemistry as described previously [32 (link)]. In brief, the 4 μm paraffin-embedded sections of the renal cortex were stained with rabbit polyclonal WT1 antibody (1 : 100; ab180840; Abcam Cambridge, MA) overnight at 4°C. Then, the sections were incubated with an HRP-conjugated secondary antibody (Bioss, Beijing, China) for 1 h at room temperature. Subsequently, the sections were incubated with streptavidin HRP (Bioss, Beijing, China). The number of WT1-positive cells in 30 randomly selected glomeruli was recorded, and the mean value per glomerulus was calculated. The results were displayed as cells/glomerulus.