Hsa-miR-494-3p attenuates gene HtrA3 transcription to increase inflammatory response in hypoxia/reoxygenation HK2 Cells

The occurrence of cardiac surgery-associated acute kidney injury (CSA-AKI) increases hospital stay and mortality. MicroRNAs has a crucial role in AKI. This objective of the current study is to explore the function of hsa-miR-494-3p in inflammatory response in human kidney tubular epithelial (HK2) cells with hypoxia/reoxygenation. According to KDIGO standard, patients after cardiac surgery with cardiopulmonary bypass were divided into two groups: AKI (n = 10) and non-AKI patients (n = 8). HK2 were raised in the normal and hypoxia/reoxygenation circumstances and mainly treated by overexpression ofmiR-494-3p and HtrA3. The relationship between miR-494-3p and HtrA3 was determined by dual-luciferase reporter assay. Our result showed that Hsa-miR-494-3p was elevated in the serum of patients with CSA-AKI, and also induced in hypoxic reoxygenated HK2 cells. Hsa-miR-494-3p also increased a hypoxia-reoxygenation induced inflammatory response in HK2 cells. Moreover, as a target gene of miR-494-3p, overexpression of HtrA3 downregulated the hypoxia-reoxygenation induced inflammatory response in HK2 cells. Overexpression of hsa-miR-494-3p-induced inflammatory response was inhibited by overexpression of HtrA3. Collectively, we identified that hsa-miR-494-3p, a miRNA induced in both circulation of AKI patients and hypoxia-reoxygenation-treated HK2 cells, enhanced renal inflammation by targeting HtrA3, which may suggest a possible role as a new therapeutic target for CSA-AKI.