IL-6 mediated renal tubular cell senescence via GATA2/ SERPINE1 pathway

Abstract

Background Acute kidney injury due to crush syndrome is a major life-threatening complication characterized by high morbidity and mortality. The role of senescence in the progression of acute kidney injury is receiving increasing attention. Our previous study has shown that remote ischemic postconditioning can attenuate kidney cell senescence and serum IL-6 from ischemia-reperfusion injury after crush injury. This raises the question of what role IL-6 plays in the progression of CS-AKI. The aim of this study was to investigate the role of IL-6 in CS-AKI. Methods Hk-2 cells were treated with 150uM ferrous myoglobin to mimic CS-AKI at the cellular level. Cells were harvested after 24 hours or treated with 100ug/ml tocilizumab for another 24 hours. RNA sequencing was performed on myoglobin and tocilizumab treated cells. The cell cycle and the percentage of senescent cells were detected by flow cytometry. The expression levels of SERPINE1, GATA2, p53, p21 were detected by real-time PCR and Western blot. The binding effect of SERPINE1 and GATA2 was verified by dual luciferase gene reporter assay. Results RNA sequencing revealed genes down-regulated by tocilizumab in HK-2 cells, including GATA2 and SERPINE1. qPCR and Western blotting confirmed that GATA2, SERPINE1, p53 and p21 expression decreased after tocilizumab treatment. The dual luciferase gene reporter verified that GATA2 acts on the promoter of SERPINE1 (PAI-1) to initiate SERPINE1 transcription. Conclusions In a word, IL-6 activates the p53/ P21 pathway through GATA2/SERPINE1, which triggers senescence in CS-AKI and then promotes the progression of AKI (Fig. 1 graphical abstract).