Purpose: Increasing evidence suggested that microRNAs (miRs) are implicated in the regulation of the inflammatory response and autophagy in multiple diseases. The present study aimed to explore the effect of miR-223-3p on inflammation and autophagy in fungal keratitis (FK).
Methods: An FK mouse model was established, and primary corneal stromal cells were isolated by inoculation with Fusarium solani. The expression of miR-223-3p was determined by quantitative RT-PCR. Subsequently, the target gene of miR-223-3p was identified by a dual-luciferase reporter assay. The levels of miR-223-3p were altered by transfecting miR agomir/antagomir to evaluate its effects. Slit-lamp biomicroscopy and hematoxylin and eosin staining were employed to detect corneal damage. The levels of autophagy were assessed by immunofluorescence, Western blotting, mRFP-GFP-LC3 fluorescence microscopy, and electron microscopy. In addition, inflammation was demonstrated by determining the proinflammatory mediators IL-1β and TNF-ɑ.
Results: Our data suggested that miR-223-3p was increased and that autophagic flux was impaired in mouse FK. Then, we confirmed that autophagy-related gene 16L1 (ATG16L1) was a potential target of miR-223-3p and that this miR negatively regulated the expression of ATG16L1. The inhibition of miR-223-3p attenuated inflammation in FK, reduced P62 expression, and increased the ratio of LC3-II/LC3-I, whereas the overexpression of miR-223-3p displayed the opposite results.
Conclusions: Taken together, miR-223-3p might regulate autophagy via targeting ATG16L1 in experimental F. solani keratitis and is associated with the inflammatory response. MiR-223-3p might be a potential therapeutic target for FK.