Down-regulation of long noncoding RNA LINC00472 alleviates sepsis-induced acute hepatic injury by regulating miR-373-3p/TRIM8 axis

Abstract

Background: The long noncoding RNAs (lncRNAs) have been confirmed to be involved in sepsis-induced organ injury. Here, we first investigated the functional role and the underlying mechanism of lncRNA LINC00472 in sepsis-induced acute hepatic injury (AHI).

Methods: Human liver THLE-3 cells were treated with lipopolysaccharide (LPS) to mimic sepsis-induced AHI in vitro; intraperitoneal injection of LPS in rats were used as an in vivo model of AHI induced by sepsis. The expressions of LINC00472, miR-373-3p, and TRIM8 mRNA were detected by qRT-PCR. The effects of LINC00472 and miR-373-3p on the viability of THLE-3 cells were assessed by CCK-8 assay. Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were performed to determine the binding relationship between LINC00472 and miR-373-3p as well as between miR-373-3p and TRIM8. The expressions of apoptosis-related proteins and TRIM8 were detected by Western blot; the levels of ALT, AST, TNF-α, IL-6, and IL-10 in the serum of rats were measured using ELSA assay.

Results: LINC00472 and TRIM8 were significantly upregulated in liver tissues and THLE-3 cells in sepsis-induced AHI models, while miR-373-3p was downregulated. Silencing of LINC00472 promoted cell viability and suppressed cell apoptosis in LPS-treated THLE-3 cells, whereas upregulation of LINC00472 had the opposite effect. Moreover, LINC00472 served as a sponge for miR-373-3p and negatively regulated its expression. miR-373-3p mimics could promote THLE-3 cell viability and suppress cell apoptosis. Additionally, TRIM8 was a direct target of miR-373-3p, which was downregulated in LINC00472-silenced cells and upregulated by the miR-373-3p inhibitor. Further, the co-transfection of miR-373-3p inhibitor reversed the effects of LINC00472 knockdown on cell viability and apoptosis. Downregulation of LINC00472 in rats restored the levels of ALT, AST, IL-6, IL-10, and TNF-α.

Conclusion: Downregulation of LINC00472 ameliorates sepsis-induced AHI by regulating the miR-373-3p/TRIM8 axis.

Keywords: Acute hepatic injury; LINC00472; Sepsis; TRIM8; miR-373-3p.