The corneal epithelium is the barrier that protects the inner corneal tissue from harmful factors. Delayed healing of the corneal epithelium after injury can result in fibrosis of the corneal stroma and the formation of irreversible corneal scarring, which in turn affects the patient's vision (Wilson, 2020). The ability of corneal epithelial cells to proliferate and migrate, as well as their ability to resist apoptosis induced by harmful factors, are key factors that affect the rate of healing and the maintenance of epithelial integrity (Ljubimov and Saghizadeh, 2015). At present, in order to promote the healing of the corneal epithelium, clinical methods such as medication, wearing corneal contact lenses, and surgical treatment are mainly used (Sharma et al., 2018; Soleimani and Naderan, 2020; Clare et al., 2022). However, there is still a lack of effective treatment for the delayed healing of the corneal epithelium caused by chemical damage. Therefore, more effective methods to promote corneal epithelial healing need to be investigated in order to reduce complications after corneal injury.

m6A modification is a dynamic and reversible process regulated by methyltransferases (Writers), demethylases (Erasers), and methylation recognition enzymes (Readers) (Zaccara et al., 2019). Methyltransferases, including METTL3, METTL14, WTAP, and KIAA1429, mainly catalyze m6A modification of adenosine monophosphate on mRNA (Oerum et al., 2021). Demethylases include FTO and ALKBH5, which function to demethylate bases that have undergone m6A modification (Zaccara et al., 2019). The main function of recognition enzymes is to recognize bases that undergo m6A modification, thereby activating downstream regulatory pathways such as RNA degradation and miRNA processing (Shi et al., 2019). Numerous studies have shown that m6A modification is involved in the proliferation, migration, and apoptosis of tumor cells, vascular endothelial cells, and chondrocytes (Yin et al., 2021; Li et al., 2024; Rong et al., 2023; Zhou et al., 2022). However, there has been no research on whether m6A modification is involved in the proliferation, migration, and apoptosis of corneal epithelial cells.

HSP70 is an important family of heat shock proteins (HSPs), which are abundant throughout the epithelial layer in the limbal, peripheral cornea, and central corneal region, mainly in the cytoplasm of the basal cells of the corneal epithelium and the nuclei of the pterygoid cells (Peterson et al., 2016). Ma et al. found that deltanp63α (human corneal limbal epithelial stem cell marker)-associated overexpression of HSPA1A may promote human corneal limbal epithelial progenitor cells to survive in amniotic membranes through the cytoprotective and anti-apoptotic effects of HSP70 (Ma et al., 2012). A study also found that Hsp70 may play a supportive role in promoting corneal wound healing by effectively inducing cell migration (Ko et al., 2008). During the healing process of corneal wounds, Hsp70 is present in corneal epithelial cells and regulates cellular behaviors such as epithelial cell growth, adhesion, and regeneration, thereby facilitating the repair process following corneal epithelial injury (Mushtaq et al., 2011). In addition, previous studies have demonstrated that m6A is involved in the regulation of HSP70 expression (Chen et al., 2023; Zhou et al., 2015; Ao et al., 2024). The increase in m6A levels in Hsp70 mRNA following heat shock regulates its cap-independent translation (Meyer et al., 2015). The differential expression of m6A-regulated heat shock proteins may depend on the abundance of m6A sites and target genes (Yu et al., 2018). However, there is still limited research on whether m6A in the cornea plays a role in regulating the expression of HSP70.

Therefore, this study investigated the effects of m6A and its regulatory factors on human corneal epithelial cells under both normal and pathological conditions by observing the changes in m6A during corneal epithelial repair. The aim of this study is to elucidate the role of m6A modification in the healing process of the corneal epithelium and to provide a new perspective for the treatment of delayed corneal epithelial healing.