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

Qian Gong,Zhi-Ming Shen,Zhe Sheng,Shi Jiang,Sheng-Lin Ge

doi:10.1038/s41598-021-81113-x

Abstract

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.

Highlights

Acute kidney injury (AKI) is a common and serious complication of hospitalized patients, which results in oliguria, anuria and elevated creatinine, and apparently increases the mortality of hospitalized p atients[1,2,3]
standard26 [serum creatinine increased by more than 0.3 mg/dL (26.5 mmol/L) within 48 h after cardiac surgery or more than 1.5 times higher than the preoperative baseline within 7 days after cardiac surgery]26, patients after cardiac surgery with cardiopulmonary bypass were divided into two groups: AKI and non-AKI patients (Fig. 1A)
The negative regulation mechanism of hsa-miR-494-3p on transcription factor 3 (ATF-3, a protein that protects kidney against stress response) protein synthesis has been clearly studied. miR-494-3p can be detected in renal tissue and urine, and it is upregulated during ischemia–reperfusion injury, which significantly inhibits the activation of ATF3, promoting the production of inflammatory mediators IL-6, MCP-1 and P-selectin in AKI model

Summary

Introduction

Acute kidney injury (AKI) is a common and serious complication of hospitalized patients, which results in oliguria, anuria and elevated creatinine, and apparently increases the mortality of hospitalized p atients[1,2,3]. CPB is considered to be the main cause of AKI after cardiac surgery, and ischemia–reperfusion injury is considered the main pathway of CPB associated-kidney injury[5,6,7,8]. Cardiac surgery-associated acute kidney injury (CSA-AKI) patients are the ideal AKI study population because the time of damage is known, and CPB provides a non-physiological condition of ischemia and hypothermia, it is a high risk factor for kidney damage. Upregulation of hsa-miR-494-3p promotes acute kidney injury by negatively regulating ATF3 protein synthesis, because ATF3 plays a protective role in renal ischemia–reperfusion injury[25]. The network regulation of hsamiR-494-3p on renal injury is the same complex as on cancer It is unclear whether hsa-miR-494-3p affects the severity of kidney injury by regulating other proteins, so we try to further study hsa-miR-494-3p on this point

Methods

Results

Conclusion