Inhibition of miR-665-3p Enhances Autophagy and Alleviates Inflammation inFusarium solani-Induced Keratitis

Abstract

PURPOSE. Accumulated evidence has shown that microRNAs (miRNAs) are closely related with the regulation of autophagy, which plays vital roles in fungal keratitis (FK). Microarray data showed elevated expression of miR-665-3p in mouse corneal tissues after infection with Fusarium solani (F. solani). Here, we investigated the effect of miR-665-3p in regulating autophagy in experimental F. solani keratitis and determined the potential molecular mechanisms involved. METHODS. In this article, we established an in vivo mouse model of FK and an in vitro model of corneal stromal cells by inoculating with F. solani. We divided them into the following six groups: control, chloroquine (CQ), rapamycin (Rapa), miR-665-3p antagomir (ant-665), miR-665-3p agomir (miR-665), and the negative control group (miR-NC). The levels of autophagy were detected by electron microscopy, Western blotting, and immunofluorescence. Then, we used a dual-luciferase reporter assay to determine the binding of miR-665-3p to the autophagy-related gene (ATG)5 3'UTR. Detection of IL-1β protein levels and hematoxylin and eosin (H&E) staining of corneal tissues were used to observe the effect of miR-665-3p on inflammation in FK. RESULTS. Here, we showed that inhibition of miR-665-3p expression in FK upregulated autophagy and alleviated inflammation. Nevertheless, the opposite results were found by overexpressing miR-665-3p. Additionally, ATG5 was a direct target gene for miR-665-3p. CONCLUSIONS. Together, our data demonstrated that miR-665-3p might be involved in F. solani keratitis of mice by regulating autophagic pathways and inflammation.

MiR-223-3p Regulates Autophagy and Inflammation by Targeting ATG16L1 in Fusarium solani–Induced Keratitis

“…1 C). We further analyzed our previous results of a miR chip on mouse fungal keratitis 17 and displayed differentially expressed miRs between fungal keratitis and the control by a volcano plot (adjusted P ≤ 0.05, |log 2 Fold-change| ≥ 2) ( Fig. 1 D).…”

“… 18 Consistent with this, we also validated an increase of miR-223-3p level in a mouse model infected with F. solani . 17 At present, the precise function of miR-223-3p in FK is still vague.…”

“…Of note, previous studies found that the levels of miR-223-3p were obviously increased in F. solani –infected mouse corneal tissues. 17 , 18 Nonetheless, the potential mechanism and biological role of miR-223-3p in FK have not been well revealed.…”

“… 21 Our previous findings also suggested that autophagy plays an indispensable role during the occurrence of FK. 17 However, the upstream pathway of autophagy in FK is unclear; thus, we attempted to identify key upstream regulators of autophagy. More recently, the regulatory influence of miR-223-3p on autophagy has attracted increasing attention.…”

Exosomes and autophagy in ocular surface and retinal diseases: new insights into pathophysiology and treatment

“…In Fusarium solani fungal keratitis (FK) mouse models, miR-223-3p might regulate autophagy via targeting ATG16L1 and was associated with the inflammatory response, which might be a potential therapeutic target [ 70 ]. Another study has demonstrated that the expression of miR-665-3p in the cornea was upregulated and autophagy flux was impaired when infected with Fusarium solani, thus miR-665-3p inhibitors might activate autophagic pathways and inhibit inflammation to cure FK [ 71 ]. The autophagy level in mice corneas increased after fumigatus infection, especially at 3 days.…”