Rosacea is a chronic skin inflammation that primarily affects the area around the eyes and on the face. The development and persistence of the illness are attributed to a number of reasons, including an altered skin immunological response and increased Demodex mite populations. Elevated levels of LL-37 and higher expression of inflammatory cytokines in rosacea skin are examples of immune response modifications. Transient receptor potential vanilloid subfamily (TRPV) receptors, particularly TRPV1, play a role in cutaneous neurogenic pain and inflammation as a nociceptive cationic channel, and can be activated by a variety of rosacea trigger factors. Consequently, we investigated the TRPV1 modulation in the rosacea and among various factors, we focused on Demodex mite colonization. First we adopted mouse model of rosacea to analyze TRPV1 expression. TRPV1 transcription were increased in murine model after repeated injection of recombinant LL-37 for 4 times in 48 hours. Next, Demodex mites obtained from rosacea patients' skin were identified and counted under the light microscope. Mites were separated and compared according to the number of mites (n = 33). qRT-PCR analysis was done to compare the different inflammatory marker expressions within the samples grouped by Demodex mite number (0 = none, 1~9 = normal, > 10 = elevated). Along with IL-1b, IL-6 and IL-8, expression of TRPV1 and nerve growth factor (NGF) are significantly elevated in human samples with elevated mite count. Additionally, the application of TRPV1 antagonist (capsazepine) in human keratinocytes treated with LL37 resulted in decreased NGF levels. Our findings suggest that increased Demodex mite colonization can contribute to neurogenic inflammation in rosacea via activation of TRPV1.

LB037 - Demodex mite contributes to neurogenic inflammation in rosacea via activation of TRPV1

The scientific meeting of the European Society for Dermatological Research (ESDR) is held yearly, usually in September. With an international attendance of more than 1000 skin scientists from around the globe, the four-day event includes short oral presentations from peer-reviewed abstracts, keynote lectures from international experts, sponsored symposia, satellite programs, educational events as well as an important focus on posters, networking and building collaborations amongst scientists. For more information about this year’s meeting visit our website.