[Growth Factor Concentration in Keratocyte Supernatant after Incubation with Human Serum In Vitro]

Application of serum eye drops is an alternative treatment option for therapy-resistant corneal epithelial defects. In case of persisting epithelial defects, cytokines, which are secreted from stromal keratocytes, may play a role in epithelial wound healing. Our aim was to analyze fibroblast growth factor basic (FGFb), hepatocyte growth factor (HGF), keratinocyte growth factor (KGF) and transforming growth factor β1 (TGF-β1) concentration in the supernatant of keratocytes, after incubation with human serum (HS).

Serum eye drops of 10 patients were prepared using the standards of the LIONS Eye Bank Saar-Lor-Lux, Trier/Westpfalz, and were stored at - 80 °C. Primary human keratocytes were isolated from human corneoscleral rings using collagenase A (1 mg/ml) (n = 1) and were cultured in DMEM/Ham's culture medium with 10% fetal bovine serum (FBS). Thereafter, keratocyte cultures were incubated in 15 or 30% HS (in DMEM/F14 without FBS) and FGFb, HGF, KGF and TGF-β1 concentration was determined with an enzyme-linked immunoabsorbent assay (ELISA) from the supernatant of the culture after 24 hours. We used 15 or 30% HS without keratocytes (under the same storage conditions) as controls.

HGF concentration was, for both HS concentrations, significantly higher in the supernatant of keratocytes, than in HS controls (without keratocytes) following 24 hours (p < 0.01). FGFb concentration was significantly increased in 30% HS with keratocytes compared to 30% HS without keratocytes after 24 hours (p < 0.01). TGF-β1 and KGF concentrations remained unchanged through keratocytes.

HGF and FGFb concentrations increase in the supernatant of keratocytes, 24 hours after incubation with human serum. These concentration changes may play a role in wound healing of epithelial defects.