Abstract
Purpose :
Epithelial-mesenchymal transition (EMT) of lens epithelial cells (LECs) is responsible for the development of fibrotic cataract, which contributes to visual impairment. Recent evidence has showed that mesenchymal stem cell-derived exosomes (MSC-Exo) can attenuate EMT in several tissues. Here, we aim to investigate the effect of MSC-Exo on LECs EMT and the underlying mechanism.
Methods :
Exosomes, derived from human umbilical cord MSCs (hucMSC-Exo) were characterized by WB, NTA, and TEM. The human LEC line FHL124 was treated with TGFβ2 to induce EMT in vitro. The expression changes of EMT markers were evaluated by immunofluorescence, qPCR and WB. In addition, EdU labeling and wound healing assay were used to analyze cell proliferation and migration, respectively. Injury-induced ASC mice model was further established and treated with hucMSC-Exo. The EMT plaque volumes with/without MSC-Exo treatment were evaluated by whole mount assay of the capsule. Finally, miRNAs contained in hucMSC-Exo were identified by qPCR. Specific miRNA mimics or inhibitors were applied, and dual-luciferase reporter assay was performed to identify miRNA target genes.
Results :
Application of hucMSC-Exo suppressed the expressions of mesenchymal cell-associated genes, while increasing the expressions of epithelial cell-associated genes in LECs-EMT. The proliferation and migration activity of LECs were inhibited after hucMSC-Exo treatment. Similarly, the volume of EMT plaque in injury-induced ASC mice was reduced significantly after hucMSC-Exo treatment. Furthermore, qPCR showed that hucMSC-Exo were rich in miR-148a-3p. After transfection with miR-148a-3p inhibitor, the anti-fibrotic effect of hucMSC-Exo was offset. Furthermore, dual-luciferase reporter assay identified the direct target gene of miR-148a-3p, PRNP, which was up-regulated in LECs-EMT, while down-regulated after hucMSC-Exo treatment. The potential downstream signaling pathway of PRNP, ERK, was activated by TGFβ2 and could be inhibited by hucMSC-Exo.
Conclusions :
HucMSC-Exo carrying miR-148a-3p downregulated the expression of PRNP and its potential downstream ERK to inhibit the epithelial-mesenchymal transition of LECs, which may provide a potential therapeutic option for fibrotic cataract.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.