MSCs helped reduce scarring in the cornea after fungal infection when combined with anti-fungal treatment

Background Fungal Keratitis (FK) is an infective keratopathy with extremely high blindness rate. The damaging effect of this disease is not only the destruction of corneal tissue during fungal infection, but also the cornea scar formed during the healing period after infection control, which can also seriously affect a patient’s vision. The purpose of the study was to observe the effect of umbilical cord mesenchymal stem cells (uMSCs) on corneal scar formation in FK. Methods The FK mouse model was made according to a previously reported method. Natamycin eye drops were used for antifungal treatment 24 h after modeling. There are four groups involved in the study, including control group, FK group, vehicle inj FK group and uMSCs inj FK group. Mice in uMSCs inj FK group received repeated subconjunctival injections of uMSCs for 3 times at the 1d, 4d and 7d after FK modeling. At 14d, 21d and 28d after trauma, clinical observation, histological examination, second harmonic generation and molecular assays were performed. Results The uMSCs topical administration reduced corneal scar formation area and corneal opacity, accompanying with decreased corneal thickness and inflammatory cell infiltration, following down-regulated fibrotic-related factors α-SMA, TGFβ1, CTGF, and COLI and finally inhibited phosphorylation of TGFβ1/Smad2 signaling pathway during FK corneal fibrosis. Conclusion The results confirmed that uMSCs can improve corneal opacity during the scar formation stage of FK, and exert anti-inflammatory and anti-fibrotic effects.