Figure 9. Schematic model depicts the mechanism by which Numb promotes TIF.
In wild type mice, the expression of Numb in TECs is induced after UUO or UIRI. Increased Numb expression leads to G2/M arrest of proximal tubular cells through stabilizing p53 protein, which in turn induces the expressions of TGF-β1 and CTGF and potentiates renal fibrosis. Tubule-specific knockout Numb reduces the number of proximal tubular cells arrested at G2/M phase (empty arrow), attenuates TIF induced by UUO or UIRI.