Circular RNA circRSF1 binds to HuR to promote radiation-induced inflammatory phenotype in hepatic stellate cells.
10.12122/j.issn.1673-4254.2023.01.06
- Author:
Pei Tao ZHOU
1
;
Bing Lin CHENG
2
;
Yi Ning SUN
1
;
De Hua WU
1
;
Yu Han CHEN
1
Author Information
1. Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China.
2. First School of Clinical Medicine, Southern Medical University, Guangzhou 510515, China.
- Publication Type:Journal Article
- Keywords:
HuR;
circular RNA;
hepatic stellate cells;
inflammatory phenotype;
radiation
- MeSH:
Humans;
Hepatic Stellate Cells/radiation effects*;
Interleukin-6;
NF-kappa B;
NF-KappaB Inhibitor alpha;
Phenotype;
RNA;
RNA, Circular/metabolism*;
Tumor Necrosis Factor-alpha;
ELAV-Like Protein 1/metabolism*
- From:
Journal of Southern Medical University
2023;43(1):46-51
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVE:To investigate whether circular RNA circRSF1 regulates radiation-induced inflammatory phenotype of hepatic stellate cells (HSCs) by binding to HuR protein and repressing its function.
METHODS:Human HSC cell line LX2 with HuR overexpression or knockdown was exposed to 8 Gy X-ray irradiation, and the changes in the expression of inflammatory factors (IL-1β, IL-6 and TNF-α) were detected by qRT-PCR. The expressions of IκBα and phosphorylation of NF-κB were detected with Western blotting. The binding of circRSF1 to HuR was verified by RNA pull-down assay and RNA-binding protein immunoprecipitation (RIP). The expressions of inflammatory factors, IκBα and the phosphorylation of NF-κB were detected after modifying the interaction between circRSF1 and HuR.
RESULTS:Knockdown of HuR significantly up- regulated the expressions of IL-1β, IL-6 and TNF-α, decreased IκBα expression and promoted NF-κB phosphorylation in irradiated LX2 cells, whereas overexpression of HuR produced the opposite changes (P < 0.05). Overexpression or knockdown of circRSF1 did not significantly affect the expression of HuR. RNA pull-down and RIP experiments confirmed the binding between circRSF1 and HuR. Overexpression of circRSF1 significantly reduced the binding of HuR to IκBα and down-regulated the expression of IκBα (P < 0.05). Overexpression of circRSF1 combined with HuR overexpression partially reversed the up-regulation of the inflammatory factors, down-regulated IκBα expression and increased phosphorylation of NFκB in LX2 cells, while the opposite effects were observed in cells with knockdown of both circRSF1 and HuR (P < 0.05).
CONCLUSION:circRSF1 reduces IκBα expression by binding to HuR to promote the activation of NF-κB pathway, thereby enhancing radiation- induced inflammatory phenotype of HSCs.
