Effect of amniotic-membrane-derived lumican on corneal epithelial cells in a chemical burn murine model

Abstract

Purpose : Amniotic-membrane-derived (AMD) lumican has significant proliferative and migratory effects, rendering it a promising alternative for epithelialization treatments. The aim of the present study was determining the effect of AMD lumican on corneal epithelial cells in a chemical burn murine model.

Methods : Lumican extracted from the amniotic membrane (AM) was stored at -20 °C until the corneal chemical burn model was performed in C57BL6 mice using 99% ethanol. Post-burn, mice were treated with topical AMD lumican (4 and 8 ng/mL), sodium hyaluronate (SH), and protease inhibitor (PI) vehicle every 4 hours for 4 days. Daily clinical assessments were conducted for epithelial integrity, and tissue collection enabled histological evaluation. Epithelial integrity was calculated as the percentage of wound closure.

Results : Wound closure was significantly higher (p<0.05) at 24 hours with 4 ng/mL AMD lumican than with 8 ng/mL AMD lumican. However, no significant difference was observed between SH and 4 ng/mL AMD lumican, as well as between SH and 8 ng/mL AMD lumican. In contrast, at 48 hours, SH significantly increased wound closure to 89.3% (p<0.05), surpassing 4 ng/mL AMD lumican (57.6%) and 8 ng/mL AMD lumican (39.6%). At 72 hours, complete wound healing occurred with 4 and 8 ng/mL AMD lumican and SH. The PI vehicle was significantly inferior (p<0.05) to 4 and 8 ng/mL AMD lumican and SH at all readings, achieving only 70.2% wound closure at 96 hours.

Histologically, 4 ng/mL AMD lumican exhibits well-defined basal layers and enhanced maturation, evidenced by smaller nuclei and elongated cells in superficial layers, while 8 ng/mL AMD lumican showed incomplete maturation, with zones of 2-3 layers, mostly basal. SH accelerates reepithelialization but lacks adequate maturation; nuclei are more basal in the superficial strata, indicating a less advanced maturation state. The protease inhibitor vehicle performed inferiorly.

Conclusions : At 4 ng/mL, AMD lumican shows superior wound closure and histological maturation, surpassing 8 ng/mL. Despite sodium hyaluronate's accelerated reepithelialization, maturation is less advanced. These results highlight AMD lumican's potential, especially at lower concentrations, in enhancing corneal healing processes.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.

 

Figure 1. 4 ng/mL AMD lumican promotes corneal wound closure from 24 hours.

 

Figure 2. Histological findings at 96 hours.