Silencing METTL3 and YTHDF2 increases HSP70 expression and promotes corneal epithelial healing

Abstract

Delayed healing of corneal epithelial injury can cause irreversible scarring and severely affect vision. Outstanding progress has been made in recent years regarding corneal epithelial repair. However, studies investigating the role of N6-methyladenosine (m6A) in this process remain limited. The main objective of this study was to explore the role of m6A modification and its regulators in the healing of the corneal epithelium. In this study, we used the C57BL/6 mouse corneal alkali burn model as an in vivo model and human corneal epithelial cells (HCECs) as an in vitro subject. Small interfering RNA (siRNA) was used to downregulate the expression of YTHDF2, METTL3, and FTO in HCECs. We evaluated the effects of downregulating m6A modification regulators on the proliferation, migration, and apoptosis of HCECs under basal conditions and following IL-1β stimulation. The results suggest that m6A and its regulators are involved in the healing process of the corneal epithelium. Following corneal alkali burns, m6A levels were elevated, while the expression of METTL3, FTO, and YTHDF2 was reduced. In HCECs stimulated with IL-1β, m6A levels were significantly increased, and the expression of FTO and YTHDF2 was decreased. Silencing METTL3 and YTHDF2 enhanced the proliferation and migration of HCECs by increasing HSP70 expression, thereby facilitating corneal epithelial healing. In contrast, silencing FTO may impede corneal epithelial healing by promoting apoptosis in HCECs and inhibiting their proliferation and migration. This study offers a novel perspective on the treatment of delayed corneal epithelial healing.