Researchers in Germany recently discovered insulin therapy could help to stimulated corneal epithelial cell migration and wound healing. When investigating the potential cellular mechanisms underlying the treatment effects, they found different concentrations of insulin had an effect on cell adhesion and increased motility, as well as regulation of the pericellular proteolytic microenvironment.

The study, presented as part of ARVO’s 2020 online meeting, enzymatically isolated human primary limbal epithelial cells from organ-cultured corneoscleral tissue. Subconfluent cell layers of five individual cell populations were incubated in serum-free medium without or with different concentrations (0.5IU to 20IU) of insulin for 24 hours.

Compared with untreated controls, insulin treatment (5IU to 20IU) significantly upregulated mRNA expression levels of its receptors, insulin receptor and insulin-like growth factor 1 receptor, as well as genes involved in cell migration.

Expression profiling revealed a set of genes that were significantly upregulated in all cell populations, including growth factors (insulin-like growth factor 1 and hepatocyte growth factor), extracellular matrix components (collagen type V and vitronectin) and proteases (matrix metalloproteinase 1 and members of the plasmin-based proteolytic cascade, e.g. PLAUR) upon exposure to 5IU insulin.

The researchers identify insulin treatment as a possible therapeutic option for patients with neurotrophic keratopathy, which  causes non-healing epithelial defects.