Abstract
Purpose :
Sulfur mustard (SM), a chemical warfare agent, can cause severe corneal inflammation and permanent damage in vision in exposed individuals. We have demonstrated that topical treatment of HDL NPs can attenuate inflammation resulting from chemical burns. We also have shown that systemic treatment with vitamin D3 can attenuate skin inflammation induced by UV irradiation. In this study, we tested the potential of topical application of HDL NPs and vitD3 as novel therapeutics in ocular injuries induced by nitrogen mustard (NM), which is an analog of SM and can mimic perturbations caused by SM.
Methods :
Mouse corneas were exposed to 0.5% NM for 1min. Corneas were treated 1hr post wounding, topically with HDL NPs, or HDL NP complexed with vitamin D3 daily for 4 weeks. To evaluate corneal clarity, mouse corneas were imaged for haze scoring. To determine epithelial integrity, corneas were stained with fluorescein and imaged. RT-qPCR was performed to examine expression of pro-inflammatory genes (e.g., Il1b, Ccl2, Inos). Whole mount staining using CD31 was conducted to visualize vessel egress into the cornea.
Results :
NM exposure caused perturbations in the anterior segment including corneal haze, epithelial cell death, severe inflammation (e.g., increased expression of Il1b, Ccl2, Inos), extensive corneal neovascularization, and conjunctivalization (e.g., goblet cells in cornea) in the central cornea. This suggests a compromise in the limbal epithelial stem cell niche and can lead to limbal epithelial stem cell deficiency. After NM injury, topical treatment with HDL NPs (1μM) significantly attenuated NM-induced detrimental effects, such as corneal haze and increased expression of pro-inflammatory genes. Interestingly, HDL NP- Vit D3 treatment further reduced: (i) the amount of corneal fluorescein staining; (ii) degree of haze; and (iii) pro-inflammatory cytokine and chemokine expression. This indicates that Vit D3 in combination with HDL NPs have a synergistic effect in the alleviation of NM-induced corneal damage.
Conclusions :
We have established a mouse model mimicking SM injured cornea. Our findings strongly suggest that topical delivery of HDL NPs and HDL NP-Vit D3 to the cornea and limbus have vast treatment potential for corneal mustard keratopathy.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.