Abstract
Purpose:
TNF-α-stimulated protein 6 (TSG-6) is a well-known anti-inflammatory protein. However, the direct effect of TSG-6 on corneal wound healing in the absence of an inflammatory background is unknown. We here investigated the effect of TSG-6 on proliferation of immortalized corneal limbal epithelial cells (HCLEs) by Oris™ Cell Migration Assay.
Methods:
An established in vitro epithelial wound-healing model was utilized in which a 1 mm diameter unique cell seeding stopper made a round wound in the center of a monolayer of confluent HCLEs. HCLEs were labeled with CellTracker Green BODIFY. Study group was comprised of HCLEs, in which 1 μg/ml TSG-6 was added to culture media, control group not given TSG-6. Wound closure was evaluated by time-lapse inverted microscopy for 24 hours. At the end of 24 hours, dead cells were stained with Red Propidium iodide (PI). The number of live HCLEs was counted in the area of wound in different time points. Dead cells were counted at the end of 24 hour.
Results:
Wound closure in the condition containing HCLEs alone took more than 24 hours, whereas the addition of TSG-6 decreased this time significantly to 14 hours. Likewise, the number of live cells without TSG-6 (1175±46.741) was significantly lower than with TSG-6 (1929±96.23, p<0.0001). In addition, number of dead cells without TSG-6 (15.26±1.007) was statistically significant higher than with TSG-6 (10.81±0.62, p=0.0004).
Conclusions:
TSG-6 promotes wound closure of corneal epithelial cells in vitro by increasing viability, proliferation, and decreasing apoptosis. Further studies are needed to dissect the molecular mechanisms of TSG-6, which increases proliferation and decreases apoptosis in corneal wound healing.