Identification of the role of PTP1B in acute kidney injury and its regulation via siRNA delivery with milk-derived extracellular vesicles

Acute kidney injury (AKI) is a critical condition marked by a sudden decline in kidney function, often triggered by ischemia-reperfusion (IR) injury. Its pathophysiology involves inflammation, oxidative stress, and endoplasmic reticulum (ER) stress. Recently, protein tyrosine phosphatase 1B (PTP1B) has been highlighted as a therapeutic target for ischemic disease due to its potential implication in activating ER stress. In this study, we observed significant overexpression of PTP1B in human kidney tissues during AKI. Additionally, in mouse models of AKI, we confirmed that this overexpression is associated with the upregulation of ER stress and inflammatory pathways mediated by Src. To explore the effect of PTP1B inhibition in AKI, we employed PTP1B-targeting siRNA (PTPi) delivered via extracellular vesicles derived from commercial milk (mEVs). PTPi@mEVs effectively reduced PTP1B expression in proximal tubular cells, decreasing ER stress and Src kinase activation. In an IR-AKI mouse, PTPi@mEVs alleviated renal dysfunction, reduced cell death, and restored gene expression related to inflammation, ROS, and ER stress. Histological analysis confirmed that PTP1B knockdown mitigated tight junction disruption in renal tissue. These findings underscore the therapeutic potential of targeting PTP1B to mitigate AKI symptoms, highlighting the efficacy of mEVs-mediated PTPi delivery in reducing acute inflammatory responses and renal dysfunction.