GATA2 promotes oxidative stress to aggravate renal ischemia-reperfusion injury by up-regulating Redd1

Abstract

Renal ischemia-reperfusion injury (RIRI) is a common pathophysiological process, and it is also an important cause of acute renal failure. Therefore, finding an effective therapeutic target for RIRI is extremely urgent. In our study, we constructed hypoxia-reoxygenation (HR) model in vitro and a renal ischemia-reperfusion (IR) model in vivo. Elevated levels of serum creatinine (Cr), blood urea nitrogen (BUN) tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and malondialdehyde (MDA) along with the decreased levels of superoxide dismutase (SOD) and glutathione (GSH) proved that kidney function was damaged after IR, and pathological changes of renal tissues were observed using HE staining and TUNEL staining. The protein of Redd1 expression level was detected to be upregulated after IR by western blot (WB). However, transfection of short hairpin RNA of Redd1 (sh-Redd1) alleviated the HR injury on LLC-PK1 cells, as evidenced by increased cell viability, proliferation and decreased cell apoptosis; additionally, the accumulation of ROS was inhibited. Sh-Redd1 also alleviated IR injury in the mouse model. Subsequently, GATA2 was proved to be upregulated in IR and HR models and was the transcription factor of Redd1. Knockdown of GATA2 efficiently mitigated the oxidative stress induced damages in vivo and in vitro, while these mitigations were reversed by transfection of Redd1 overexpression plasmid. In conclusion, our study clarified the possible underlying mechanism of protecting RIRI.