3.4 | Epithelial cell-specific overexpression of PSTPIP2 ameliorates AAI-induced AKI in mice
To understand the function of PSTPIP2, we established a mouse model of PSTPIP2-KI, specifically in the renal proximal tubules (Figure 5A). The mice were genotyped using PCR (Figure 5C). We treated PSTPIP2-KI mice for follow-up experiments (Figure 5B). AAI induced a significant increase in BUN and Cr levels, markers of kidney injury, in wild-type mice. However, in PSTPIP2-KI mice, there was no alteration in kidney function (Figure 5D). Macroscopically, PSTPIP2 can significantly improve renal function, which is related to the improved preservation of kidney morphology. Histological analysis with HE staining revealed a significant decrease in tissue damage in PSTPIP2-KI mice compared with that in wild-type mice (Figure 5E). Therefore, we biochemically characterized the activation of key PANoptotic proteins (GSDMD-N, pMLKL, and cleaved caspase-3) in the kidneys of AAN mice. We found decreased activation of these molecules in the kidneys of PSTPIP2-KI mice compared with that of wild-type mice treated with AAI (Figure 5F, 6A). To confirm whether the downregulation of PANoptosis is driven by the renoprotection of PSTPIP2, an overexpressed PSTPIP2 cell culture model was established. This indicates that pstpip2 overexpression downregulates AAI-induced PANoptosis in AAN. In support of this hypothesis, we found that the robust activation of PANoptotic markers was reduced in the overexpressing PSTPIP2 mTECs compared with that in control cells during AAI treatment (Figures 6B, C).