Induction effect of DNCB on atopic dermatitis BALB/c mice and its mechanism / 吉林大学学报(医学版)

ABSTRACT

Objective: To induce the atopic dermatitis (AD) by 2, 4-dinitrobenzene (DNCB) in the BALB/c mice, and to explore the possible mechanism of DNCB as hapten to induce AD. Methods: A total of 12 BALB/c mice were randomly divided into control group (n = 6) and AD model group (n = 6). The dorsal skin of the mice in AD model group was sensitized by 1.0% DNCB at days 1, 4, and 7 and the back skin of the left ears were challenged by 0. 5% DNCB at days 14, 17, 19, 22, 24, 27, and 29. The mice in control group were given substrate solution with the same volume at the same time points. The inflammation scores of the skin tissue of the mice in two groups were evaluated, the appearance changes of the ear skin of the mice in two groups were observed, the pathomorphology of the skin tissue in left ear of the mice in two groups were observed by HE staining and toluidine blue staining, the epidermal thickness of the skin tissue at lesion site of the mice in two groups was measured, and the number of mast cells in the skin tissue at lesion site of the mice in two groups was counted; the expression levels of interleukin-4 (IL-4) in the skin tissue at lesion site of the mice in two groups was detected by immunohistochemistry staining, and the levels of serum IgE was detected by ELISA method. Results: The inflammation score of the mice in AD model group was higher that in control group (P < 0. 01). The skin tissue in left ear of the mice in AD model presented as redness swelling and hardening accompaning with abnormal scratching marks; the epidermal thickness, the number of mast cells, the expression level of IL-4 in skin tissue at lesion site and the level of serum IgE of the mice in AD model group were all increased compared with control group (P < 0. 05 or P < 0. 01). Conclusion: The AD mouse can be successfully induced by 1. 0% DNCB for sensitizing and 0. 5% DNCB for chllenging in the BALB/c mice, and its mechanism may be related with the increasing of IL-4 expression level in skin tissue and IgE level in serum.