Abstract
Purpose :
Previously we identified that the miR-183/96/182 cluster (miR-183C) modulates corneal response to Pseudomonas aeruginosa (PA) infection by regulating corneal nerve function and innate immunity1-3.Local application of anti-miR-183C in a prophylactic regimen causes a transient, reversible reduction of corneal nerve density and protects against PA keratitis4. This study is to test whether topical application of anti-miR-183C alone in a therapeutic regimen has similar effects on corneal nerves and PA keratitis.
Methods :
8 weeks old, female C57BL/6 mice were used. Under anesthesia, the cornea of the left eye was scarified by three 1-mm incisions using a 25 5/8-gauge needle. 5.0 × 106 CFU PA (strain 19660; ATCC) in 5 μl was topically delivered. Six or 24 hours after infection and twice daily thereafter, 5 μl of anti-miR-183C or negative-control oligoribonucleotides (NC ORN) in sterile saline (8 μM/each) was topically applied to the infected cornea for 5 days. To test the effect of anti-miR-183C alone on corneal nerves, anti-miR-183C or NC ORNs were topically applied to the cornea 24 hours after a mock infection and twice daily thereafter. At 5 days post (mock) infection (dpi), immunofluorescence (IF) of flat-mounted corneas with bIII-tubulin antibody was done and corneal nerve density was determined.
Results :
Topical application of anti-miR-183C resulted in a significant reduction of corneal nerve density. To test whether anti-miR-183C-induced reduction of corneal nerves causes permanent changes to corneal nerves, after the last topical application, another group of anti-miR-treated mice were held for another week without any treatment. Our result showed that their nerve density was fully recovered. Preliminary data on PA-infected corneas showed that topical application of anti-miR-183C significantly reduced the severity of the disease at 3 dpi (p<0.05); at 5 dpi, anti-miR-183C treated eyes had slightly decreased severity, however, didn’t pass the statistical threshold (p=0.09).
Conclusions :
Topical application of anti-miR-183C causes transient and reversible corneal nerve density reduction and has a therapeutic potential against PA keratitis. Further studies to optimize the treatment regimen and uncover the molecular mechanisms of the therapeutic effect are warranted.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.