3.5 | AAV9-mediated restoration of PSTPIP2 increased renal dysfunction while promoting renal injury and PANoptosis in AAI-treated PSTPIP2-KI mice
To further elucidate the function of PSTPIP2, PSTPIP2 depression was rescued in PSTPIP2-KI mice using an AAV9-packaged PSTPIP2 depression plasmid (Figure 7A, B). We observed that restoring PSTPIP2 expression increased BUN levels, serum CRE levels, and renal damage (Figure 7C, D). Furthermore, IHC staining and western blotting analyses showed that restoration of PSTPIP2 induced GSDMD-N, pMLKL, and cleaved caspase-3 production and programmed cell death in AAI-induced PSTPIP2-KI mice (Figure 7E, 8A). These data indicate that PSTPIP2 plays a key role in the occurrence and development of AKI.
To confirm our hypothesis that PSTPIP2 mediates FK-228-mediated suppression of AAI-induced PANoptosis, PSTPIP2 was knocked down by transfection of small interfering RNA targeting PSTPIP2 into mTECs. FK-228-mediated suppression of AAI-induced epithelial cell PANoptosis was abolished by PSTPIP2 knockdown (Figure 8B, C). Hence, PSTPIP2 primarily functions by inhibiting the PANoptosis of mTECs in AKI. Therefore, the FK-228-mediated induction of PSTPIP2 and PSTPIP2-mediated suppression of AAI-induced epithelial cell PANoptosis suggests that FK-228 mediates its effect through PSTPIP2.