AURKA regulates HBV-induced hepatic stellate cell inflammation and liver fibrosis by modulating K48-linked ubiquitination and proteasomal degradation of TLR3.

Abstract

Chronic hepatitis B (CHB), caused by persistent hepatitis B virus (HBV) infection, continues to pose a major global health threat. Aurora kinase A (AURKA) has been implicated in fibrosis, yet its role in HBV-induced liver fibrosis remains unclear. This study investigated the function and mechanism of AURKA in hepatic stellate cell (HSC) activation and fibrogenesis during CHB. Bioinformatics screening of GSE83148 dataset and validation in human CHB liver specimens, LX-2 HSCs treated with conditioned medium (CM) from HBV-replicating cells, and a persistent HBV recombinant cccDNA (rcccDNA) mouse model established by tail-vein injection of Ad/rcccDNA were performed. Gene and protein expression was analyzed by quantitative PCR and immunoblotting, respectively. Cytokine levels were measured by ELISA. Mitochondrial function was assessed via ROS and JC-1 assays. Protein interactions and ubiquitination were evaluated by co-immunoprecipitation (Co-IP) and protein stability assays. In additional experiments, LX-2 cells were stimulated with purified HBV virions at varying MOIs to assess direct viral effects. AURKA was significantly upregulated in CHB patients and HBV-CM-treated LX-2 HSCs. In LX-2 HSCs, AURKA knockdown attenuated HBV-CM-induced inflammatory cytokine secretion (IL‑1β, IL‑6), mitochondrial dysfunction (mitochondrial ROS, mitochondrial membrane potential), HSC proliferation, and fibrotic marker expression (COL I, α-SMA). Mechanistically, AURKA interacted with TLR3 and was associated with its K48-linked polyubiquitination and degradation. TLR3 silencing abolished the protective effects of AURKA knockdown. In vivo, using a persistent HBV rcccDNA mouse model, AURKA knockdown ameliorated HBV-induced hepatic inflammation and fibrosis by upregulating TLR3. Notably, purified HBV virions alone were sufficient to dose-dependently induce AURKA expression and downstream fibrotic responses in HSCs. This study identifies a novel AURKA/TLR3 axis that regulates HBV-induced HSC activation and liver fibrosis, positioning AURKA as a potential therapeutic target for CHB-associated fibrosis.