Alpha-NETA, as a CMKLR1 Small Molecule Antagonist, Protects againstRenal Ischemia Reperfusion Injury in Mice

Background: Ischemia-reperfusion (IR) injury is one of the major causes of acute kidney injury (AKI). Chemerin chemokine-like receptor 1 (CMKLR1) has been reported to be involved in the progression of IR injury. Here, we investigated the protective role of CMKLR1 antagonist, α-NETA, in IR mouse model, and dissected the underlying regulatory mechanism. Methods: IR injury mouse model was established to evaluate the protective effects of α-NETA on IR injury. Kidney injury-associated parameters and functions were examined to evaluate the renal function of Sham, IR, and IR+ α-NETA mice. Renal morphological changes and apoptosis were determined by PAS and TUNEL staining in IR and α-NETA treated mice. ELISA, RT-qPCR, and western blot were performed to examine the inflammatory responses and expression of CMKLR1. Results: α-NETA administration attenuated IR-induced renal tubular injury and epithelial cell apoptosis in IR injury mice. Kidney injury-related cystatin C, kidney injury molecule-1, neutrophil gelatinaseassociated lipocalin, and renal morphology were significantly improved. Mechanistically, α-NETA suppressed the inflammatory responses by inhibiting the expression of CMKLR1, and then protected the IR-induced renal damage and restored renal function. Conclusion: CMKLR1 plays an important role in renal ischemia-reperfusion injury, targeting CMKLR1 by using the small molecule inhibitor α-NETA is a potential treatment strategy for AKI.