Abstract
Purpose :
The aim of this study was to investigate the effects of mesenchymal stem cells derived exosomes on the ultrastructure of corneal epithelium and function of the tear film in a dry eye mouse model.
Methods :
Twenty four healthy adult male BALB/c mice were selected in this study and divided into four groups randomly (A,B,C and D),with each group consisting of 6 mice.The dry eye model was induced by eye drop of 0.1% benzalkonium chloride and established in group A, group B and group C. Group D served as the normal control without any treatment. The A group was given 0.025ug/ml mesenchymal stem cells derived exosomes eye drop, while the B group was given PBS eye drop ,each treatment was performed three times a day for 7 consecutive days and the C group did nothing as the model control. The Schirmer I test, tear break-up time (BUT), corneal fluorescein staining (FL) and rose bengal staining, Lissamine Green staining were evaluated before therapy and on day 1,4,7 after dropping eyes. The corneas samples of all mice were collected on day 7 for hematoxylin and eosin staining,and ultrastructure of corneal epithelial cells was examined by transmission electron microscopy(TEM).
Results :
There were no statistical changes in tear volume, BUT, FL and rose bengal staining, Lissamine Green staining before therapy among A,B,C three groups (P＞0.05).Before therapy, the mean tear volume of group A was 2.92 mm,which increased to 5.25 mm at 1 week with exosomes eye drop in group A, and the number of corneal chondriosome/desmosomes was obviously increased in group A and the morphological features of microvilli and desmosomes were normal which is close to those at baseline in the normal control group D. Significantly less tear volume, shorter tear break-up time, higher corneal fluorescein staining score, shorter and flattened, disordered corneal epithelial microvilli, and looser intercellular desmosomes were observed in group B and C .
Conclusions :
The exosomes derived from mesenchymal stem cells have improved corneal epithelial ultrastructure and tear film function in this model.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.