To investigate the efficacy and mechanisms of human umbilical cord-derived MSC-derived extracellular vesicles (hucMSC-EVs) in a mouse model of desiccation-induced dry eye disease (DED).

hucMSC-EVs were enriched by ultracentrifugation. The DED model was induced by desiccating environment combined with scopolamine administration. The DED mice were divided into the hucMSC-EVs group, fluorometholone (FML) group, PBS group, and blank control group. Tear secretion, corneal fluorescein staining, the cytokine profiles in tears and goblet cells, TUNEL-positive cell, and CD4+ cells were examined to assess therapeutic efficiency. The miRNAs in the hucMSC-EVs were sequenced, and the top 10 were used for miRNA enrichment analysis and annotation. The targeted DED-related signaling pathway was further verified by using RT‒qPCR and western blotting.

Treatment with hucMSC-EVs increased the tear volume and maintained corneal integrity in DED mice. The cytokine profile in the tears of the hucMSC-EV group presented with a lower level of proinflammatory cytokines than PBS group. Moreover, hucMSC-EVs treatment increased goblet cell density and inhibited cell apoptosis and CD4+ cell infiltration. Functional analysis of the top 10 miRNAs in hucMSC-EVs showed a high correlation with immunity. Among them, miR-125 b, let-7b, and miR-6873 were conserved between humans and mice and were associated with the IRAK1/TAB2/NF-κB pathway that is activated in DED. Furthermore, IRAK1/TAB2/NF-κB pathway activation and the abnormal expression of IL-4, IL-8, IL-10, IL-13, IL-17, and TNF-α were reversed by hucMSC-EVs.

hucMSCs-EVs alleviate DED signs, suppress inflammation and restore homeostasis of the corneal surface by multitargeting the IRAK1/TAB2/NF-κB pathway via certain miRNAs.