USP10 from Human Umbilical Cord Mesenchymal Stem Cells-Derived Extracellular Vesicles Mediates SCL7A11 Deubiquitination in Epithelial Cells: A Key to Anti-ferroptosis and Anti-fibrosis in Pulmonary Fibrosis

Objective: Pulmonary fibrosis (PF) is a lethal lung disease distinguished by deteriorating pulmonary function. This study investigated whether human umbilical cord mesenchymal stem cells (HUMSCs) alleviate PF in mice by suppressing Ferroptosis through Ubiquitin-Specific Protease 10 (USP10)-mediated deubiquitination of solute carrier family 7 member 11 (SLC7A11).

Methods: A bleomycin (BLM)-induced PF mouse model was established and treated with HUMSCs or Erastin. In vitro, BEAS-2B cells were challenged with BLM and co-cultured with HUMSCs, with further manipulations using si-SLC7A11, si-USP10, or oe-USP10. USP10 expression in the characterized HUMSCs-derived extracellular vesicles (EVs) were measured by western blot techniques. Lung edema, histopathology, fibrosis, Collagen deposition, and hydroxyproline were assessed. Ferroptosis, cell viability, cell death, lipid peroxidation, SLC7A11/USP10 expression, and fibrosis were analyzed by CCK-8, Lactate Dehydrogenase, BODIPY 581/591 C11 staining, RT-qPCR, and western blot assays. USP10-SLC7A11 interaction, SLC7A11 ubiquitination, and protein stability were evaluated using Co-immunoprecipitation and cycloheximide chase assay.

Results: BLM-induced PF mice exhibited aggravated lung injury, enhanced fibrosis and Ferroptosis, and reduced Glutathione Peroxidase 4, SLC7A11, and USP10 expression. USP10 was enriched in HUMSCs-EVs. HUMSCs significantly upregulated USP10, attenuated PF, and suppressed Ferroptosis in vivo and in vitro. USP10 knockdown or SLC7A11 downregulation reversed the protective effects of HUMSCs. Mechanistically, BLM-induced downregulation of USP10 increased SLC7A11 ubiquitination and reduced its protein stability. In vivo experiments validated that HUMSCs-mediated USP10/SLC7A11 mitigated BLM-induced PF in mice by inhibiting Ferroptosis.

Conclusions: HUMSCs-EVs ameliorate BLM-induced PF by inhibiting Ferroptosis through USP10-mediated deubiquitination of SLC7A11, highlighting a novel therapeutic mechanism for MSC-based therapy in PF.