The Role Of TNFAIP3 In The Pathogenesis Of Psoriasis Vulgaris

Background:Psoriasis vulgaris is an immune-mediated inflammatory skin disorder.It affects about 0.47%of the population in China.It is difficult to totally cure this disease because of its'chronicity and recurrence.The pathogenesis of psoriasis is still unclear,which limits the exploration and development of effective treatment methods.Therefore,it exists the great theoretical value and social significance to explore the mechanism of psoriasis.Tumor necrosis factor alpha-induced protein 3(TNFAIP3),also known as zinc finger protein A20,is a protein that is widely expressed in the cytoplasm and can be negatively regulated through NF-?B signaling.TNFAIP3 plays an important role in the differentiation and function of a variety of immune cells,including B cells,T cells,dendritic cells,and macrophages.In the field of psoriasis,current studies believe that the TNFAIP3 gene polymorphism is related to the severity of psoriasis and is related to the response of tumor necrosis factor antagonists to the treatment of psoriasis.Previous studies have found that the expression level of TNFAIP3 in psoriasis skin lesions is different from that of the control group,but the results of the study are not consistent.The expression of TNFAIP3 in peripheral blood lymphocytes of psoriasis and the mechanism of action are still unclear.Therefore,this study intends to study the role of TNFAIP3 in the pathogenesis of psoriasis from the perspective of clinical specimens and mouse models of psoriasis.Also,the immunomodulatory effects of TNF-? antagonists were examined.Objects:1.We selected 23 patients with moderate to severe psoriasis vulgaris with PAS I score greater than 10 who were clinically or pathologically diagnosed in the Dermatology Clinic of Peking Union Medical College Hospital from April 2019 to June 2019.Twenty-five healthy controls(HCs)matched for age and gender were enrolled as a control group.2.BALB/c mice at 7-8 weeks of age(male,20± 2 g)were selected and shaved on their back.The mice were randomly divided into 4 groups(6-8 mice in each group):control group,IMQ group,IMQ/rat IgG1 group,and IMQ/anti-TNF-? group.A daily topical dose of 62.5 mg of 5%imiquimod cream or control Vaseline was applied to the shaved dorsal skin of the mice for six consecutive days.Mice in the IMQ/rat IgG1 group and IMQ/anti-TNF-? group were intraperitoneally injected with 200 ?g anti-TNF-? antibody or control rat IgG1 1 day before(day 0)and 3 days after the imiquimod treatment(day 3).Mice were humanely euthanized on day 7 followed by sample collection including the mouse serum,peripheral blood PBMC,skin lesions,and spleens.Methods:1.The relative expression of TNFAIP3 mRNA in the PBMC(peripheral mononuclear blood cell)of the psoriasis patients and the healthy control was determined by RT-PCR method.2.We established a mouse psoriasis model induced by imiquimod cream,and apply vaseline cream to the control group.3.We observed the skin changes of the 4 groups of mice,and recorded the modified psoriasis area and severity index(PASI)score.4.Pathological skin changes of the four groups of mice were observed by hematoxylin-eosin(HE)staining.5.We used RT-PCR to determine the relative mRNA expression of TNFAIP3 in the PBMC of the four groups of mice.6.Enzyme-linked immunosorbent assay(ELISA)was used to determine the levels of serum cytokines of the four groups of mice.7.Flow cytometry was used to detect the proportion of Th1 and Th17 cells in the spleen of the control group and psoriasis mice.8.The phosphorylation levels of JNK,ERK1/2 and P38 in the serum of the four groups of mice were determined by ELISA.Results:1.The mRNA expression level of TNFAIP3 in peripheral blood PBMC of moderate to severe psoriasis patients was significantly lower than that of the normal control group(p<0.01).2.Imiquimod-induced mouse psoriasis model was successfully established.The psoriasis treatment drug TNF-? inhibitor can inhibit the occurrence and development of psoriasis-like dermatitis in mice and inhibit the abnormal proliferation of keratinocytes and the infiltration of inflammatory cells in the mouse skin.3.The expression level of TNFAIP3 mRNA in peripheral blood PBMCs in IMQ treated mice was significantly lower than that of control mice,while TNFAIP3 expression in the IMQ/anti-TNF-? group was upregulated after treatment with TNF-? antagonists.4.The expression of Th1 and Th17 related cytokines and the proportion of Th1 and Th17 cells in the mouse spleen were significantly higher in the IMQ treated mice compared with the control group.The application of TNF-? antagonists significantly decreased the levels of Thl and Th17 cytokines related cytokines in the IMQ-induced psoriasis-like dermatitis model.5.The level of phosphorylated p38 in peripheral blood in IMQ treated mice was significantly higher than that in the control group,and TNF-? inhibitors can inhibit the activation of p38 MAPK pathway.Conclusions:1.The expression of TNFAIP3 in peripheral blood PBMC was lower in psoriasis patients and IMQ treated mice,which is closely related to the occurrence and development of psoriasis.2.The low expression of TNFAIP3 in peripheral blood PBMC of psoriasis mice is accompanied by the increase of Th1,Th17 cells and their related cytokines and the activation of p38 pathway,indicating that the regulatory role of TNFAIP3 in psoriasis is asscociated with the T cell differentiation and the p38 signaling pathway.3.TNF-? inhibitors may intervene the imiquimod-induced psoriasiform dermatitis via upregulating TNFAIP3,inhibiting Th1/Th17 differentiation and p38 pathway activation.