Abstract
Purpose :
We examined TNF-α-stimulated gingival MSC (GMSC)-exosomes for their neuroprotective and anti-inflammatory effects in retinal IRI. We further aim to explore the crucial factors and pathways involved in protective mechanisms of GMSC-derived exosomes.
Methods :
In this study, exosomes from the CM of GMSCs were isolated by ultracentrifugation. Exosomes from conditioned culture medium (CM) of MSCs stimulated by TNF-α were injected to cell and the vitreous of mouse model. The effects of TNF-α-stimulated gingival MSC (GMSC)-exosomes (TG-exos), in modulating inflammatory microglia and alleviating apoptosis was detected by PCR, western blot analysis, immunofluorescence staining assay.
Results :
The results showed that intraocular injection of TG-exos into mice with IRI notably reduced inflammation and cell loss than that with G-exos (GMSC-exosomes). Similar results were observed in vitro. Additionally, with the microRNA (miR) arrays, it was found that miR-21-5p acted as a crucial factor in TG-exos for neuroprotection and anti-inflammation. Following target prediction and dual luciferase assay suggested that miR-21-5p played a role by combining with programmed cell death 4 (PDCD4), which was regulated by the long non-coding RNA (lncRNA) maternally expressed gene 3 (MEG3) as a competing endogenous RNA (ceRNA).
Conclusions :
This study demonstrates a new therapeutic pathway for neuroprotection against IRI by delivering miR-21-5p-enriched exosomes through MEG3/miR-21- 5p/PDCD4 axis and paves the way for the establishment of a cell-free therapeuticapproach for glaucoma.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.