Deletion of Antigen-Presenting Cells in Lipopolysaccharide-Induced Acute Kidney Injury (AKI) Affects the Exacerbation and Repair in AKI.

The pathogenesis of acute kidney injury (AKI) is complex and involves various immune and inflammatory responses. Antigen-presenting cells such as macrophages and dendritic cells (DCs) were recently reported to have diverse functions in AKI depending on the pathogenesis and disease phase. Herein, we intraperitoneally administered liposomal clodronate (LC) to lipopoly-saccharide (LPS)-induced AKI model mice in order to deplete antigen-presenting cells (e.g., macrophages and DCs). After the LPS injection, the mice were divided into LC-treated (LPS + LC) and saline-treated groups (LPS), and the immune responses of macrophages and DCs in the acute and recovery phases were evaluated. The LPS + LC-treated group exhibited significantly suppressed renal macrophages and DC infiltration at 18 h and improved survival at 120 h after LPS injection. Via the depletion of macrophages and DC infiltrations, the serum and renal tissue inflammatory cytokines/chemokines were suppressed at 18 h and reversed at 120 h. Tubular kidney injury molecule-1 expression was decreased at 18 h and increased at 120 h. These findings indicate that LC administration suppressed tubular and interstitial injury in the acute phase of AKI and affected delayed tissue repair in the recovery phase. They are important for understanding innate and acquired immune responses in the therapeutic strategy for LPS-induced AKI.