The role and mechanism of PKM2 in the development of LPS-induced acute kidney injury

Abstract

A previous study suggested that pyruvate kinase M2 (PKM2) plays a vital role of metabolic reprogramming in the regulation of the innate inflammatory response, while PKM2 is a sensitive biomarker for nephrotoxicity. In this study, we investigated the role and mechanism of PKM2 in development of LPS-induced acute kidney injury. The AKI model of mice was established using LPS. The serum levels of blood urea nitrogen (Bun), creatinine (Cr), and Cystatin C (CysC) were identified using the enzyme-linked immunosorbent assay (ELISA). Hematoxylin and Eosin staining (H&E) was employed to assess pathological changes in kidney tissues of LPSinduced AKI model. Immunohistochemical staining and Western blot analysis were carried out to determine the expression of apoptosis-related factors at protein levels. We found that Bun, CysC, and Cr were significantly increased in the LPS group compared with the control group. The histopathological assay showed model swollen tubular epithelial cells and the presence of vacuolar degeneration in the LPS-induced AKI. In addition, expression levels of PKM2 significantly increased in the LPS group compared with the control group at both protein and mRNA levels (P<0.01). The inhibition of PKM2 by shikonin notably suppressed the expression of HIF-1α and apoptosis-related factors such as BNIP3, Bax, and Caspase-3, while the inhibition of PKM2 by shikonin significantly improved the histopathological symptoms of LPS-induced AKI. This study demonstrated the potential role of PKM2 in LPSinduced AKI and identified PKM2 as a promising therapeutic target in the treatment of AKI.