Study: Common Fatty Acid Contributes to Pain, Temperature Sensitivity in Psoriasis Plaques

Linoleic acid, a common fatty acid, can break down into compounds that contribute to increased pain and temperature sensitivity in psoriatic lesions, according to the results of a study published in JID Innovations.

The findings could potentially lead to a better understanding of how lipids interact with sensory neurons and lead to improved pain and sensitivity treatment for individuals with psoriasis.

“We noticed high levels of 2 types of lipids derived from linoleic acid in psoriatic lesions,” Santosh Mishra, associate professor of neuroscience at North Carolina State University and an author of the study, said in a statement.

“That led us to wonder whether the lipids might affect how sensory neurons in these lesions communicate. We decided to investigate whether their presence could be related to the temperature or pain hypersensitivity that many psoriasis patients report,” Mishra said.

Linoleic acid is found in nuts, seeds, and vegetable oils, and is also 1 of the predominant fatty acids found in Western diets. The fatty acid also plays a role in skin barrier function.

Investigators used mass spectrometry to create lipid profiles from the skin of psoriatic lesions. They focused on 2 oxylipids, which were linoleic acid-deprived lipids: 13 hydroxy-9,10-epoxy octadecenoate (9,13-EHL) and 9,10,13-trihydroxy-octadecenoate (9,10,13-THL).

9,13-EHL can convert into 9,10,13-THL when there is an interaction from certain enzymes.

Investigators found that when both forms bind to receptors on sensory neurons within the skin, 9,10,13-THL had a longer lasting effect than 9,13-EHL.

“We know that this lipid moves from one form to another, but don’t yet know what causes that,” Mishra said.

“We also know what protein the lipids are binding to but not where the bond occurs. Answering these questions may hopefully lead to new therapies, or dietary solutions, for some psoriasis sufferers,” Mishra said.

Additionally, investigators found that once the lipids bind to the neuronal receptors, they activate neurons expressing TRPA1 and TRPV1 receptors that are involved with pain and temperature hypersensitivity and opened communication channels to the central nervous system.

Investigators noted that these lipids did not have any effect on itch.

“It was surprising that these lipids could create hypersensitivity but not impact itch sensation, which is usually the most troublesome symptom associated with psoriasis,” Mishra said. “This most likely has to do with how the neuron is activated: a mechanism we still haven’t uncovered.”

Investigators want to further explore how the response of the association between linoleic acid and hypercreativity to temperature and pain is created. They are hopeful that the answers can lead to solutions that help relieve the symptoms of those who live with psoriasis.

The research is supported by the National Institute on Aging and the National Institutes of Health.

Reference

Common fatty acid contributes to temperature and pain sensitivity in psoriasis plaques. EurekAlert. News release. January 3, 2022. Accessed January 5, 2023. https://www.eurekalert.org/news-releases/975553