Abstract
Purpose :
Corneal transparency is vital for proper vision and often the epithelium is wounded during infection or ocular surface disorders that lead to vision loss. Failure in timely wound healing of corneal epithelium leads to corneal ulceration that makes restitution of vision difficult. Therefore, an efficient wound healing process is required to maintain corneal integrity and vision. Host defense peptides (HDP) are widely studied as a potent alternative to treat microbial infections. We have recently shown that calgranulin C, a HDP, can efficiently inhibit P. aeruginosa and reduce bacterial burden in vivo. The therapeutic potential will be elevated further if the peptide exhibits accelerated corneal wound healing along with the antibacterial property. In this study, we aim to determine the role of calgranulin C in wound healing both in vitro and in vivo using a standardized murine model of corneal wound healing. Our purpose is to understand the downstream signaling pathways involved in the process.
Methods :
Human corneal epithelial cells were used for in vitro wound closure model. Briefly, a scratch was made mimicking the wound with a sterile P200 pipette tip on a confluent cell layer and treated with the peptide. Cells were observed and imaged at different time points and wound closure was measured using Image J software. In vivo, corneas of C57BL/6 mice were scratched with 26-gauge needles, and treated with peptide for different time points. The corneas were imaged 24 h post-wounding using fluorescein dye and wound closure was followed. The signaling pathways involved in the process was determined by quantitative PCR, immunoblot and immunocytochemistry assays.
Results :
We found that calgranulin C along with its antimicrobial property significantly increased cellular migration and proliferation of corneal cells in vitro and facilitated wound closure at early time points compared to control. Accelerated healing of corneal wound in vivo was also observed in corneas treated with the peptide compared to sham treated control. The peptide activated EGFR and MAPK signaling pathways in corneal epithelial cells to facilitate wound healing. Increased expression of several cytokines like TGFβ, CXCL5 and CXCL10 was also observed in presence of the peptide.
Conclusions :
These findings provide new insights about the wound healing property of calgranulin C that can be further explored for developing novel therapies for corneal wounds.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.