Developing and identifying effective medications and targets for treating hepatic fibrosis is an urgent priority. Our previous research demonstrated the efficacy of artesunate (ART) in alleviating liver fibrosis by eliminating activated hepatic stellate cells (HSCs). However, the underlying mechanism remains unclear despite these findings. Notably, endocytic adaptor protein (NUMB) has significant implications for treating hepatic diseases, but current research primarily focuses on liver regeneration and hepatocellular carcinoma. The precise function of NUMB in liver fibrosis, particularly its ability to regulate HSCs, requires further investigation. This study aims to elucidate the role of NUMB in the anti-hepatic fibrosis action of ART in HSCs. We observed that the expression level of NUMB significantly decreased in activated HSCs compared to quiescent HSCs, exhibiting a negative correlation with the progression of liver fibrosis. Additionally, ART induced senescence in activated HSCs through the NUMB/P53 tumor suppressor (P53) axis. We identified NUMB as a crucial regulator of senescence in activated HSCs and as a mediator of ART in determining cell fate. This research examines the specific target of ART in eliminating activated HSCs, providing both theoretical and experimental evidence for the treatment of liver fibrosis.
Hepatic Stellate Cells/cytology* ; Liver Cirrhosis/genetics* ; Artesunate/pharmacology* ; Cellular Senescence/drug effects* ; Membrane Proteins/genetics* ; Animals ; Humans ; Nerve Tissue Proteins/genetics* ; Tumor Suppressor Protein p53/genetics* ; Male ; Mice

Senescence of activated hepatic stellate cells (aHSCs) is a stable growth arrest that is implicated in liver fibrosis regression. Senescent cells often accompanied by a multi-faceted senescence-associated secretory phenotype (SASP). But little is known about how alanine-serine-cysteine transporter type-2 (ASCT2), a high affinity glutamine transporter, affects HSC senescence and SASP during liver fibrosis. Here, we identified ASCT2 is mainly elevated in aHSCs and positively correlated with liver fibrosis in human and mouse fibrotic livers. We first discovered ASCT2 inhibition induced HSCs to senescence in vitro and in vivo. The proinflammatory SASP were restricted by ASCT2 inhibition at senescence initiation to prevent paracrine migration. Mechanically, ASCT2 was a direct target of glutaminolysis-dependent proinflammatory SASP, interfering IL-1α/NF-κB feedback loop via interacting with precursor IL-1α at Lys82. From a translational perspective, atractylenolide III is identified as ASCT2 inhibitor through directly bound to Asn230 of ASCT2. The presence of -OH group in atractylenolide III is suggested to be favorable for the inhibition of ASCT2. Importantly, atractylenolide III could be utilized to treat liver fibrosis mice. Taken together, ASCT2 controlled HSC senescence while modifying the proinflammatory SASP. Targeting ASCT2 by atractylenolide III could be a therapeutic candidate for liver fibrosis.