Docosanoid Signalingmodulates Corneal Nerve Regeneration: Effect on Tear Secretion, Wound Healing, and Neuropathic Pain
Journal of Lipid Research
The cornea is densely innervated,mainly by sensory nerves of the ophthalmic branch of the trigeminal ganglia (TG). These nerves are important to maintain corneal homeostasis, and nerve damage can lead to a decrease in wound healing, an increase in corneal ulceration and dry eye disease (DED), and neuropathic pain. Pathologies, such as diabetes, aging, viral and bacterial infection, aswell as prolonged use of contact lenses and surgeries to correct vision can produce nerve damage. There are no effective therapies to alleviate DED (a multifunctional disease) and several clinical trials using ω-3 supplementation show unclear andsometimesnegativeresults.Using animalmodels of corneal nerve damage, we show that treating corneas with pigment epithelium-derived factor plus DHA increases nerve regeneration, wound healing, and tear secretion. The mechanism involves the activation of a calcium-independent phospholipase A2 that releases the incorporated DHA from phospholipids and enhances the synthesis of the docosanoids, neuroprotectin D1 (NPD1) and a newresolvin stereoisomer, resolvinD6i (RvD6i).NPD1 stimulates the synthesis of brain-derived neurotrophic factor, nerve growth factor, and semaphorin 7A. RvD6i treatment of injured corneas modulates gene expression in the TG resulting in enhanced neurogenesis, decreased neuropathic pain, and increased sensitivity. Taken together, these results represent a promising therapeutic option to reestablish the homeostasis of the cornea.
Taylor and Francis Group
Pham, Thang L. and Bazan, Haydee E.P., "Docosanoid Signalingmodulates Corneal Nerve Regeneration: Effect on Tear Secretion, Wound Healing, and Neuropathic Pain" (2021). School of Medicine Faculty Publications. 205.