Therapeutic Effects of Q-Switched 1064 nm Nd:YAG Laser on Rosacea in a Mouse Model: Inflammation and Angiogenesis...

Rosacea is a chronic inflammatory skin condition with a complex pathogenesis involving immune dysregulation and angiogenesis. Q-switched 1064 nm neodymium:yttrium-aluminum-garnet (QSNY) laser has been demonstrated as an effective treatment for rosacea; however, studies investigating histological changes following QSNY treatment are limited. This study aims to evaluate the therapeutic effects of QSNY and explore its underlying mechanisms.

A rosacea-like mouse model was established by intradermal injection of LL37 into BALB/c mice. Hematoxylin and eosin (H&E) staining, along with immunohistochemical staining for myeloperoxidase (MPO) and CD31, were performed to assess inflammation and angiogenesis. mRNA expression levels of rosacea-associated markers were analyzed using real-time quantitative PCR (RT-qPCR) on RNA extracted from skin lesions.

QSNY treatment significantly reduced skin erythema and inflammatory cell infiltration in a rosacea-like mouse model. The number of CD31- and MPO-positive cells were notably decreased following QSNY treatment. Additionally, the mRNA expression levels of rosacea-associated genes, including Toll-like receptor 2 (TLR2), kallikrein 5 (KLK5), cyclic adenosine monophosphate (cAMP), elevated interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), vascular endothelial growth factor (VEGF)-1, and VEGF-2 were downregulated.

QSNY effectively mitigates the rosacea phenotype by suppressing inflammation and angiogenesis, highlighting its potential as a therapeutic strategy for rosacea.