Therapeutic potential of mesenchymal stem cell-derived apoptotic vesicles in liver fibrosis: targeting the IGFBP3/PI3K-AKT axis via miR-409-3p.

backgroundHepatic fibrosis is a progressive pathology driven by hepatic stellate cell (HSC) activation and excessive extracellular matrix deposition. While mesenchymal stem cell (MSC) therapies show promise, their clinical translation is hindered by the inherent safety constraints of live cell transplantation. MSC-derived apoptotic vesicles (MSC-ApoVs), a structurally distinct class of extracellular vesicles, emerge as a compelling cell-free alternative. However, their specific therapeutic efficacy and mechanistic targets in hepatic fibrosis remain elusive.

methodsMSC-ApoVs were isolated from human umbilical cord MSCs and stringently characterized to exclude non-vesicular contaminants. Their anti-fibrotic efficacy was evaluated in vitro using TGF-β1-activated LX-2 cells and in vivo within a CCl₄-induced murine fibrosis model. To elucidate and functionally validate the underlying mechanisms, we integrated transcriptomic profiling (RNA-seq), dual-luciferase reporter assays, and dual-directional pharmacological interventions. Furthermore, human clinical liver biopsies were analyzed to determine the clinico-pathological relevance of the identified targets.

resultsWe demonstrated that MSC-ApoVs were efficiently internalized by HSCs, significantly blunting TGF-β1-induced activation, proliferation, and migration, alongside a marked reduction in fibrotic markers (α-SMA, MMP2, and Collagen-I). Transcriptomic screening identified Insulin-like Growth Factor Binding Protein 3 (IGFBP3) as a crucial pro-fibrotic mediator. Mechanistically, MSC-ApoV-enriched miR-409-3p directly targeted and downregulated IGFBP3, thereby restricting the PI3K-AKT signaling cascade-a dependency unequivocally validated by targeted rescue and blockade assays. In vivo, systemic MSC-ApoV administration robustly ameliorated CCl₄-induced hepatic fibrosis and restored liver function. Crucially, clinical analyses revealed a strong positive correlation between elevated IGFBP3 expression and the severity of human fibrotic progression.

conclusionsThis study delineates a novel cell-free therapeutic paradigm, demonstrating that MSC-ApoVs mitigate hepatic fibrosis largely through the miR-409-3p-mediated silencing of the IGFBP3/PI3K-AKT axis. By integrating robust in vitro, in vivo, and clinical evidence, these findings highlight MSC-ApoVs as a highly efficacious and translatable alternative to traditional live stem cell therapies for hepatic fibrosis.