310 nm UV-LEDs attenuate imiquimod-induced psoriasis-like skin lesions in C57BL/6 mice and inhibit IL-22-induced STAT3 expression in HaCaT cells.

Abstract

Ultraviolet light-emitting diodes (UV-LEDs) are a novel light source for phototherapy. This study aimed to evaluate the therapeutic effects of UV-LEDs on psoriasis. Importantly, 310 nm UV-LEDs have not been studied in psoriasis in vitro and in vivo. Effects due to 310 nm UV-LED and 311 nm narrowband ultraviolet B (NBUVB) irradiation were compared for suppressing IL-22-induced activation of STAT3 expression using cell viability assay, western blotting, and immunocytochemistry. C57BL/6 mice were topically treated with imiquimod (IMQ) for 6 consecutive days and degenerative changes were observed. Test groups were irradiated with a 310 nm UV-LED and 311 nm NBUVB. Phenotypic observations, histopathological examinations, and ELISA were conducted with skin and blood samples. STAT3-dependent IL-22 signalling and effects in keratinocytes are negatively regulated by the 310 nm UV-LED, which significantly ameliorated IMQ-induced psoriasis-like dermatitis development and reduced Th17 cytokine levels (IL-17A, IL-22) in serum and dorsal skin. Histopathological findings showed decreases in epidermal thickness and inflammatory T-cell infiltration in the UV-LED-irradiated groups. Quantitative PCR confirmed a UV radiation energy-dependent decrease in IL-17A and IL-22 mRNA levels. The results demonstrated that UV-LEDs had anti-inflammatory and immunoregulatory effects. So, UV-LED phototherapy inhibits psoriasis development by suppressing STAT3 protein and inflammatory cytokines and could be useful in treating psoriasis.

• Authors: Tae-Rin Kwon, Sung-Eun Lee, Jong Hwan Kim, You Na Jang, Su-Young Kim, Seok Kyun Mun, Chan Woong Kim, Jungtae Na, Beom Joon Kim
• Journal: Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology (Photochem Photobiol Sci) Vol. 19 Issue 8 Pg. 1009-1021 (Aug 01 2020) ISSN: 1474-9092 [Electronic] England
• PMID: 32584352 (Publication Type: Journal Article)

Chemical References

• Antineoplastic Agents
• Interleukins
• STAT3 Transcription Factor
• STAT3 protein, human
• Imiquimod

Topics

• Animals
• Antineoplastic Agents (pharmacology)
• HaCaT Cells
• Humans
• Imiquimod (pharmacology)
• Inflammation (chemically induced, pathology, therapy)
• Interleukins (metabolism)
• Mice
• Mice, Inbred C57BL
• Psoriasis (chemically induced, pathology, therapy)
• STAT3 Transcription Factor (biosynthesis)
• Skin (drug effects, pathology)
• Ultraviolet Rays
• Interleukin-22