HSA-MIR-203/MyD88 axis mediates the protective effect of hispidulin on LPS-induced apoptosis in a human renal tubular epithelial line, HK-2

Sicong Wang,Ruijin Liu,Kaijiang Yu,Qiuyuan Han

doi:10.32604/biocell.2022.013027

Abstract

Acute kidney injury (AKI), commonly occurring as complications of sepsis, cardiac surgery, and liver or kidney transplantation, is a critical care syndrome. It is well known that lipopolysaccharide (LPS) shock is a common triggering factor for AKI. This study is aimed to examine the effect of flavonoid compound hispidulin on LPS-induced AKI. For this, renal tubular epithelial cell HK-2 was treated with LPS to establish an in vitro model of AKI. The effect of hispidulin on HK-2 cell viability was examined using CCK-8 assay. Cell apoptosis was determined by TUNEL and flow cytometry. Apoptosis marker proteins were determined by using western blot. The levels of pro-inflammatory cytokines were determined by ELISA assay and qRT-PCR. The translocation of NF-κB was determined by western blot. The effect of MyD88 on the cytoprotective activities of hispidulin was examined by overexpressing MyD88 in HK-2 cells. Our results showed that hispidulin was not able to produce a cytotoxic effect on HK-2 cells at tested concentrations. However, hispidulin could protect HK-2 cells from LPS-induced cell injury. Our results also showed that hispidulin was able to attenuate LPS-induced HK-2 cell apoptosis. In addition, LPS led to an inflammatory response in HK-2 cells, evidenced by NF-κB p65 activation as well as increased expression and release of inflammatory cytokine IL-6 and TNF- α, which could be reversed by pretreatment with hispidulin. Overexpression MyD88 was found to significantly dampen the cytoprotective activities of hispidulin against LPS insult. More importantly, MyD88 was identified as a direct target of hsa-miR-203, and hispidulin was found to regulate the expression of MyD88 via upregulating hsa-miR-203. Our results showed that hispidulin attenuates LPS-induced HK-2 damage via regulating hsa-miR-203/MyD88 axis.

Highlights

Acute kidney injury (AKI), featured by a rapid decrease in renal function, has been considered as a critical care syndrome (Kölling et al, 2018)
HK-2 cells were incubated with hispidulin at 2, 5, and 10 μM for 24 h, and the cell viability was assessed via Cell counting kit-8 (CCK-8) assay
HK-2 cells were pretreated with hispidulin at indicated concentrations for 24 h before challenged with LPS at 2 μg/mL for 12 h

Summary

Introduction

Acute kidney injury (AKI), featured by a rapid decrease in renal function, has been considered as a critical care syndrome (Kölling et al, 2018). The discovery of agents that can alleviate LPS-induced renal injury is necessary (Mccoy et al, 2019). By post-transcriptionally regulate gene expression by binding to 3’-untranslated regions (3’-UTR) of target mRNAs, miRNAs play a key role in the pathogenesis of a variety of human conditions (Zhang et al, 2019). MiRNA-20a has been recently found to suppress LPS-induced HK-2 cell injury (Zhang et al, 2020). MiR-188 has been reported to augment contrast-induced acute kidney injury in vivo and in vitro (Liu, 2019)

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