3.4 TRPA1 deficiency inhibits DNCB-induced infiltration of macrophages in AD mice
In chronic AD, the increase of macrophage infiltration is closely related to the degree of skin damage and immune dysfunction. To verify the effect of TRPA1 on macrophage infiltration in DNCB-induced AD, the expression of F4/80 in the back skin was analyzed by immunofluorescence and Western blot. The results showed that the number of F4/80+ cells and its protein expression significantly increased after repeated skin stimulation with DNCB. Compared with the WT group, the number of F4/80+ cells and its protein expression in TRPA1-/- group decreased (Figure 5A-5B ).
There are two main pathways for macrophage activation, the classical M1 pathway and the alternative M2 pathway. In this study, we explored the effect of TRPA1 on the infiltration of M1 and M2 macrophages. The results showed that the expression of iNOS+ and CD206 protein induced by DNCB were significantly increased and in the TRPA1-/- group, the expression of iNOS+ and CD206 protein decreased compared with the WT group (Figure 5A ). These results suggest that TRPA1 deficiency inhibits the infiltration of M1 and M2 macrophages in the lesions.