LAUSR

Aims Gluaredoxin1 (GRX1) is an important protein of the cellular antioxidant defense system, but its role in renal epithelial cell injury caused by ischemia remains unclear. In this study, we aimed to gain insight into the role of GRX1 in HK‐2 cells with oxygen glucose deprivation (OGD) injury, which served as an in vitro cell model of renal epithelial cell ischemic injury. We investigated the underlying regulation of GRX1, DJ‐1, and HSP70 as well as the role of the GRX1/DJ‐1/HSP70 signaling pathway in this model. Materials and methods The protein and mRNA expressions were measured by Western blot and qRT‐PCR assays, respectively. GRX1 was overexpressed by transfection of pcDNA.3.1‐GRX1 and DJ‐1 was inhibited by transfection with DJ‐1 siRNA. Cell apoptosis, caspase‐3 activity, lactate dehydrogenase (LDH) leakage, or superoxide dismutase (SOD) content was tested by the related detection kit. Reactive oxygen species (ROS) level was detected via carboxy‐H2DCF‐DA. Key findings We found that GRX1 was distinctly down‐regulated in HK‐2 cells after incubation under the OGD condition. GRX1 overexpression markedly constrained cell apoptosis, caspase‐3 activity, LDH leakage, and the ROS level, while SOD content was elevated. GRX1 up‐regulation increased DJ‐1 and HSP70 protein expression, while DJ‐1 inhibition significantly offset the effect of GRX1 overexpression on HSP70, indicating that GRX1 could regulate HSP70 via control of DJ‐1. Moreover, we observed that HSP70 inhibition removed the constraints imposed by GRX1 overexpression on ROS level, LDH leakage, and caspase‐3 activity. Significance Overall, this study showed that GRX1 minimizes cell injury and apoptosis in HK‐2 cells under OGD conditions via regulation of DJ‐1 and HSP70 expression. HighlightsGRX1 is decreased in HK‐2 cells after OGD injury.GRX1 overexpression inhibits OGD‐induced oxidative stress and LDH leakage in HK‐2 cells.GRX1 overexpression suppresses OGD‐induced apoptosis.GRX1 regulates HSP70 via controlling DJ‐1 expression.GRX1 protects HK‐2 cells from OGD injury via regulation of HSP70.