Abstract
Purpose :
Corneal blindness due to scarring is treated with corneal transplantation. However, there exists a global challenge of donor material shortage. Various pre-clinical studies have shown that donor corneal stromal stem cells (CSSCs) inhibited corneal inflammation, fibrosis, and scar tissue formation in acute corneal stromal wounds. This study examined whether the CSSC treatment reduced established (pre-existing) opacities in mouse corneas.
Methods :
Ex vivo cultivated human CSSCs from donor corneas (n=10) were characterized for the expression of stem cell markers, matrix metalloproteinases (MMPs), and regenerative cytokines by qPCR. Using a mouse model of established stromal opacities, CSSCs were applied topically in a fibrin gel on corneas with opacities after the removal of corneal epithelium. The scar modulatory effect was assessed up to 4 weeks post-treatment. Corneas were examined weekly with anterior segment optical coherent tomography (ASOCT) followed by 3D reconstruction of OCT images, and opacity density and volume analyses using Fiji and a customized Python-based tool. Corneas were harvested for fibrosis marker expression by qPCR. The association of scar-reducing efficiency and expression of stromal remodeling factors was assessed with multivariate analysis.
Results :
Donor CSSCs expressed stem cell markers (ABCG2 and nestin). The treatment with CSSC batches modulated stromal opacities. A batch-by-batch-related difference in opacity densities and volumes was observed. The expression of fibrosis genes (Col3a1, αSMA, fibronectin, and tenascin C) was significantly downregulated by CSSCs, which strongly expressed MMP-2 and 14 and transforming growth factor β3 (p<0.05, Kruskal-Wallis multiple comparisons). The scar-reducing efficiency was associated with MMP2/TIMP2 ratios (One-way ANOVA).
Conclusions :
Topical CSSC treatment reduced established corneal opacities. Cells expressing stromal remodeling and regenerative factors showed strong scar-reducing ability. Our work has demonstrated the potential use of ex vivo expanded human CSSCs for treating clinically relevant corneal scarring.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.