AZITHROMYCIN REGULATES ANXA1-SUPPRESSED NOTCH1/NF-ΚB PATHWAY TO INHIBIT M1 MACROPHAGE POLARIZATION AND ATTENUATES LPS-INDUCED AKI.

Background

Acute kidney injury (AKI) is a common and severe form of renal dysfunction, characterized by inflammation and damage to tubular epithelial cells. Azithromycin (AZM) possesses anti-inflammatory and immunomodulatory properties. In this study, we aim to elucidate the underlying functional roles of AZM in lipopolysaccharide (LPS)-induced AKI.

Methods

C57BL/6 mice (7 weeks old) were used to construct the AKI models in vivo . The serum creatinine (Scr) level, blood urea nitrogen (BUN) levels, tubular damage score, and NGAL-positive expression were examined using Scr and BUN assay kits, hematoxylin and eosin staining, and immunohistochemistry, respectively. The reverse transcription-quantitative polymerase chain reaction (qRT-PCR) and western blot were performed to detect the levels of target genes. The cell viability was examined using cell counting kit-8 (CCK8). The interleukin (IL)-6, IL-1β, tumor necrosis factor-alpha (TNF-α), and IL-10 levels were analyzed using corresponding enzyme-linked immunosorbent (ELISA) detection kits. The macrophage polarization was detected using western blot and flow cytometry.

Results

AZM reduced Scr level, BUN levels, tubular damage score, and NGAL-positive expression rate in LPS-induced AKI model in vivo . AZM repressed IL-6, IL-1β, TNF-α, inducible nitric oxide synthase (iNOS), and CD86 levels and promoted IL-10 and Arginase-1 levels in LPS-induced AKI group. Additionally, AZM suppressed LPS-induced M1 macrophage polarization in vitro . AZM expedited ANXA1 expression and inhibited notch receptor 1 and nuclear factor kappa B subunit 1 expression in vivo and in vitro . Furthermore, AZM alleviated inflammation and M1 macrophage polarization through ANXA1 upregulation.

Conclusion

AZM remits LPS-induced AKI by regulating M1 macrophage polarization via regulating ANXA1 and notch receptor 1/nuclear factor kappa B subunit 1 pathway. These findings may accelerate the translation of clinical drugs for the treatment of LPS-associated AKI.