Effects of Mdivi-1 on imiquimod-induced psoriasis-like skin inflammation in mice
To investigate the effect of mitochondrial division inhibitor 1(Mdivi-1)on imiquimod(IMQ)-induced psoriasis-like skin inflammation in mice and its mechanism,female 8-week-old C57BU6 mice were recruited and randomly divided into control group,IMQ model group,IMQ+Mdivi-1 experiment group.IMQ was used to induce the psoriasis-like skin inflammation model in mice.The mice in the experiment group were injected intraperitoneally(i.p.)with Mdivi-1,and the mice in the control group and model group were injected with the same volume of solvent.The mice were sacrificed on the 7th day for sampling.Psoriasis area and severity index(PASI)score was used to evaluate the severity of skin lesions in each group;the reactive oxygen species(R0S)content in skin tissue was detected by fluorescence staining of frozen section;HE staining was used to observe the histomorphologic change of skin lesions;immunohistochemical staining was used to detect the expression of dynamin-related protein 1(Drp1)in the skin of mice;Western blot was used to detect the protein levels of Drp1,NLRP3 and IL-1β in the skin tissues of mice in each group;and the expressions of IL-17A and IL-18 in mouse serum were detected by ELISA.Data showed that the model group had typical psoriatic lesions such as erythema,scale and thickening,and the Mdivi-1 group demonstrated obvious reduction of the lesions.The PASI score of the experiment group was significantly lower than that of the model group.HE staining indicated that the epidermal thickness of the back skin in the treatment group was significantly lower than that in the model group,and Munro microabscess was significantly reduced.R0S fluorescence staining indicated that ROS content in the experiment group was significantly lower than that in the model group;immunohistochemical results showed that the expression of Drp1 protein in the experiment group was significantly lower than that in the model group;Western blot results showed that the expression levels of Drp1,NLRP3 and IL-1 β in the experiment group were significantly lower than those in the model group;ELISA results indicated that the expressions of IL-17A and IL-18 in serum of mice in the experiment group were lower than those in the model group.Taken together,Mdivi-1 can reduce mitochondrial damage and ROS production by inhibiting the expression of Drp1,thereby reducing the production of NLRP3 inflammasome,down-regulating IL-1 β,IL-18 and IL-17A,and alleviating the IMQ-induced psoriasis-like skin inflammation in mice.