Contribution of itch-associated scratch behavior to the development of skin lesions in Dermatophagoides farinae-induced dermatitis model in NC/Nga mice

Abstract

Recently, we have reported that the pathophysiological features of dermatitis induced by the repeated application with Dermatophagoides farinae (Df) extract ointment in NC/Nga mice were similar to those observed in the patients with atopic dermatitis. In the present study, we first examined whether the application of Df in other mouse strains could induce dermatitis. The repeated application of Df body (Dfb) ointment to the barrier-disrupted back of ICR, C57BL/6, and Balb/c mice did not cause any apparent skin lesions, although transient increase in serum immunoglobulin E (IgE) levels during antigen application was observed. On the other hand, in NC/Nga mice, dermatitis scores and serum IgE levels increased remarkably, and then these changes sustained for at least 10 days after stopping of antigen elicitation. Using NC/Nga mice, we investigated the contribution of scratching behavior to the development and maintenance of Dfb-induced dermatitis. In correlation with the increase in scratching behavior, erythema, hemorrhage, edema, scarring, erosion and excoriation were observed. Cutting off the hind toenails of mice exhibiting chronic skin lesions dramatically alleviated the dermatitis. From these findings, the onset of skin lesions and its chronically sustained course in Dfb-induced dermatitis in NC/Nga mice were closely associated with increased scratching behavior.

The Inhibitory Effect of S-777469, a Cannabinoid Type 2 Receptor Agonist, on Skin Inflammation in Mice

“…In addition, a single dose of S-777469 suppressed the nerve fiber sprouting into the epidermis 24 h after the administration of mite antigen in a mouse model of atopic dermatitis (data not shown). Moreover, we reported that cutting of toenails suppressed mite antigeninduced skin inflammation in NC/Nga mice [34] . Therefore, it is possible that the anti-inflammatory effects of S-777469 are partially mediated by the inhibition of pruritus.…”

Effects of Anti-inflammatory and Rehmanniae radix Pharmacopuncture on Atopic Dermatitis in NC/Nga Mice

“…The subclinical macroscopic observations were made using the methods of Yamamoto et al [18]. The total clinical skin score for the AD-like lesions on the NC/Nga mice was defined as the sum of individual scores, graded as 0 (none), 1 (mild), 2 (moderate), or 3 (severe), for each of four signs and symptoms (erythema/hemorrhage, scarring/ dryness, edema, excoriation/erosion) on the back skin.…”

Protective effects of Opuntia humifusa cladode extracts against biostir AD-induced atopic dermatitis in NC/Nga mice

“…Representative images were also captured using a handscope (X50; AT Trading). In the final week of the experimental period, clinical evaluation was performed with the unaided eye using the Yamamoto et al (15) method, which is a standard method for evaluation of atopic dermatitis. Skin was evaluated according to the 4 categories of erythema/hemorrhage, dryness/scaling, edema, and excoriation/erosion.…”

“…Observations were made over the course of 3 weeks with a 1 week interval. Clinical skin scores (15) were measured for experimental and control group mice. Representative images were also captured using a handscope (X50; AT Trading).…”