Csi-miR-71a delivered by Clonorchis sinensis extracellular vesicles suppresses liver fibrosis by targeting Scube3 to inhibit the TGF-β/Smad and PI3K/AKT signaling pathways

Clonorchis sinensis is a major food-borne parasite that contributes to liver fibrosis in the host by activating hepatic stellate cells (HSCs) and promoting extracellular matrix deposition. Recent studies have revealed that miRNAs carried by C. sinensis-derived extracellular vesicles (EVs) have important roles in host-parasite interactions. However, their specific functions and underlying regulatory mechanisms in liver fibrosis remain largely unclear. In this study, EVs were isolated from C. sinensis excretory-secretory products and characterized by electron microscopy, nanoparticle tracking, and western blotting. Fluorescent labeling confirmed their uptake by HSC-T6 cells, suggesting direct parasite-host communication. Small RNA sequencing of EVs and HSCs isolated from infected and uninfected mice revealed that Csi-miR-71a was significantly enriched in both EVs and infected HSCs. To investigate the function of this miRNA, synthetic mimics, inhibitors, and lentiviral vectors were used in HSC-T6 cells, primary HSCs, and mouse liver tissues. Overexpression of Csi-miR-71a suppressed fibrotic markers (α-smooth muscle actin, collagen type I, and collagen type III), whereas Csi-miR-71a inhibition had the opposite effect. In a CCl4-induced mouse model, lentiviral delivery of Csi-miR-71a alleviated liver fibrosis, as shown by reduced collagen deposition and fibrotic gene expression. Bioinformatic analyses and dual-luciferase assays identified signal peptide-CUB-EGF-like domain-containing protein 3 (Scube3) as a direct target of Csi-miR-71a, and co-immunoprecipitation confirmed the interaction with transforming growth factor (TGF)-β receptor II. Scube3 silencing reduced Smad2/3 and PI3K/AKT phosphorylation. Conversely, restoration of SCUBE3 expression in Csi-miR-71a mimic-treated HSC-T6 cells rescued fibrosis-associated protein expression and reactivated both signaling pathways, supporting SCUBE3 as a major functional mediator of Csi-miR-71a activity. These findings demonstrated that Csi-miR-71a, specifically enriched in EVs from C. sinensis, suppressed liver fibrosis by targeting Scube3 to inhibit the TGF-β/Smad and PI3K/AKT pathways. Together, these results reveal a previously unrecognized miRNA-mediated mechanism by which C. sinensis modulates host fibrosis responses, providing novel insights into parasite-host molecular crosstalk and suggesting a potential regulatory target for liver fibrosis.

Abstract from PubMed (PMID 43024685). This entry was added automatically by our daily literature monitor because it matches the topics we follow; read the full paper at the original source.