Abstract
Purpose :
Previously, studies in our Lab have shown that the treatment with a galectin-3 inhibitor, GB1265, reduces corneal fibrosis. To detect the impact of GB1265 treatment specifically on fibrosis-related genes, we analyzed differentially expressed genes by Nanostring technology using the fibrosis panel.
Methods :
Corneal fibrosis was induced by alkali-burn injury in C57B/6 mice. Vehicle alone or GB1265 (10µl of 10mg/ml in vehicle) were topically applied to the eye twice per day from day 1 until day 14. Corneal opacity was scored by slit lamp examination at day 7 and 14 post-injury. On day 14, corneas were harvested, isolated RNA was processed for Nanostring analysis using a mouse fibrosis panel that profiles 770 genes across 51 annotated pathways. Differentially expressed genes were analyzed using nCounter gene expression platform analysis. Subset of genes involved in fibrosis pathway were confirmed by Q-PCR and immunohistochemical staining.
Results :
Of the 770 genes in the panel, 230 genes were not expressed above background, 9 genes were not expressed in all replicates (n = 3), 128 genes were not affected by GB1265 treatment. Of the remaining 540 genes, 11.5% were differentially expressed in GB1265-treated corneas compared to vehicle-treated corneas (fold change >2.0; false discovery rate q <0.05). Of the 55 differentially expressed genes in the inhibitor treated group, 52 were downregulated, and 3 were upregulated. MMP-9 and -12, Collagen I and V, LOXL-1 and -2 and Itgb3 were among the significantly downregulated genes. Pathway analysis of differentially expressed genes revealed that three fibrosis-related pathways i.e. TGFβ pathway, Th17 differentiation, and collagen biosynthesis were downregulated whereas none of the pathways were upregulated in the GB1265-treated corneas.
Conclusions :
Our data indicated that galectin-3 inhibitor plays an important role in reducing corneal fibrosis by downregulating fibrosis-related genes in the corneas treated with GB1265. This leads us to conclude that GB1265 is an effective galectin-3 inhibitor and could be a potential candidate for developing a new drug to halt the progression of fibrosis after injury.
This is a 2021 ARVO Annual Meeting abstract.