Lipid Accelerates Corneal Wound Healing, Study Finds

the The lipid dioleoyl-phosphatidylglycerol (DOPG) accelerates healing of corneal epithelial wounds, according to a study published in Investigative Ophthalmology & Visual Science.

“Blindness from corneal etiologies is a serious global issue limiting the productivity and quality of life of approximately 4.9 million people around the world,” researchers said. “Although corneal wounds generally heal rapidly, in a subset of patients, these wounds heal slowly (so-called refractory corneal wounds) or recur, particularly in patients with other comorbidities such as diabetes.”

They hypothesized the functions of corneal epithelial cells and keratinocytes, which make up the epidermis, may be regulated by similar mechanisms, due to the fact that both cell types express many of the same genes and proteins. DOPG also naturally helps skin wounds heal.

The investigators used co-immunoprecipitation, immunohistochemistry, and scratch wound healing assays in vitro to determine how the aquaporin-3 (AQP3)/phospholipase D2 (PLD2)/phospholipid phosphatidylglycerol (PG) signaling pathway functions in corneal epithelial cells.

“DOPG accelerated scratch wound closure of immortalized corneal epithelial cells in culture by about 40%, comparable to the approximately 60% stimulation observed with the positive control, epidermal growth factor,” the authors said.

The researchers grew human cornea cells in a laboratory from dishformalin-fixed human corneas supplied by the Georgia Eye Bank. The 3 methods of testing revealed:

• Human corneas showed AQP3 immunoreactivity that localized primarily to corneal epithelial cell borders
• AQP3 and PLD2 partially co-localize in human corneal limbal epithelial cells and human cornea
• AQP3 and PLD2 co-immunoprecipitate from immortalized human corneal epithelial cells
• DOPG enhances scratch wound healing of immortalized corneal epithelial cells in vitro

These findings indicate “a topical application of DOPG, possibly even adding it to existing eye drop products, could one day aid healing of this important protective barrier after injury as well as after common eye procedures like cataract surgery,” the authors explained in a press release.

The investigators also found the response to DOPG was biphasic, in that a higher concentration resulted in a lower rate of wound healing compared with a lower concentration. There should be future investigations and clinical trials in order to determine optimal DOPG concentration to stimulate wound healing.

“We demonstrate that a particular PG species, DOPG, which shows the greatest efficacy in stimulating the proliferation of slowly dividing epidermal keratinocytes, was able to enhance scratch wound healing of corneal epithelial cells in vitro,” the researchers concluded.

Reference

Bollag WB, Olala LO, Xie D, et al. Dioleoylphosphatidylglycerol accelerates corneal epithelial wound healing. Invest Ophthalmol Vis Sci. 2020;61(3):29. doi: 10.1167/iovs.61.3.29.