Study On The ApoE^-/- Mouse Psoriasis Model Induced By Imiquimod And The Expression Of Antigen Presentation Related Genes In Psoriatic Lesions

Objective1.Using imiquimod（IMQ）to induce psoriatic dermatitis based on Apolipoprotein E knockout mice(ApoE^-/-),To investigate and analyze the associations between psoriasis and dyslipidemia,antigen presentation related genes（ERAP1、CARD14、STAT3、CD1a）,skin structure related genes（GJB2、LCE）,and psoriasis related cytokines（IL-36α、IL-36γ、IL-22）in the above animal models.To investigate the expression of related genes in ApoE^-/-mouse psoriasis induced by IMQ at the level of animal models and inflammatory molecules,and to clarify their possible mechanism of action in the occurrence and development of the disease.2.To investigate the protein expressions of antigen-presenting genes ERAP1、HLA-C and CD1a in psoriatic lesions by case-control study,and to analyze the correlation of these genes in psoriasis vulgaris.Methods1.Animal experimental research:Twelve male ApoE^-/-and C57BL/6 mice aged 6-8 weeks were fed the same high-fat diet for 16 weeks and divided into ApoE^-/-control group,ApoE^-/-+IMQ group,C57BL/6 control group and C57BL/6+IMQ group.After back shaving,mice in IMQ group were applied with5%IMQ cream locally,62.5 mg/time,to induce psoriasis mouse model,while those in control group were applied with Vaseline cream for control.The mice were sacrificed after successful model construction.Indirect enzyme-linked immunosorbent assay（ELISA）was used to detect the protein expression levels of IL-36α、IL-36γand IL-22 in mouse serum,and Real-time Quantitative nucleic acid assay（qPCR）were used to detect the mRNA expression levels of ERAP1、CARD14、LCE、GJB2、STAT3 and CD1a in skin tissues,and to observe whether there were differences among the groups.2.Clinical case Studies:Patients with psoriasis diagnosed clinically and histopathologically were divided into psoriasis vulgaris（PsV）group and generalized pustular psoriasis（GPP）group.Normal skin tissues were used as control group.Immunohistochemical staining was used to observe and compare the protein expressions of ERAP1、HLA-C and CD1a in each group.IOD values and positive cell ratios of the stained images were calculated using Image-pro plus 6.0 software,and statistical analysis was performed using SPSS 26.0 statistical software.Results1.Animal experimental research:（1）ELISA:The expression of IL-36αin ApoE^-/-+IMQ group was higher than that in ApoE^-/-control group,C57BL/6 control group and C57BL/6+IMQ group,and the expression of IL-36αin C57BL/6+IMQ group was higher than that in C57BL/6+IMQ group,with statistical significance（P<0.05）.The expressions of IL-22 and IL-36γin ApoE^-/-control group,ApoE^-/-+IMQ group,C57BL/6 control group and C57BL/6+IMQ group were not statistically significant（P>0.05）.（2）qPCR:The expression of ERAP1 in ApoE^-/-+IMQ group was higher than that in ApoE^-/-+IMQ group,and the expression of Erap1 in C57BL/6+IMQ group was higher than that in C57BL/6 control group,with statistical significance（P<0.05）.The expressions of CARD14 and STAT3 in ApoE^-/-+IMQ group were higher than those in ApoE^-/-control group,C57BL/6 control group and C57BL/6+IMQ group,and the difference was statistically significant（P<0.05）.There were no significant differences in the expressions of LCE,GJB2and CD1a in ApoE^-/-control group,ApoE^-/-+IMQ group,C57BL/6 control group and C57BL/6+IMQ group（P>0.05）.2.Clinical case Studies:（1）Immunohistochemistry:The ratio of HLA-C positive cells in PsV group was higher than that in GPP group,and the difference was statistically significant（P<0.05）.The IOD value of HLA-C in PsV group was higher than that in control group and GPP group,and the difference was statistically significant（P<0.05）.The positive cell ratio and IOD of ERAP1 in PsV group and GPP group were higher than those in control group,and the difference was statistically significant（P<0.05）.The positive cell ratio and IOD value of CD1a in PsV group were higher than those in control group,the difference was statistically significant（P<0.05）.（2）Correlation analysis:In PsV group,there was a positive correlation between HLA-C and CD1a fluorescence IOD（r_s=0.370,P=0.022）.The fluorescence IOD value of CD1a was negatively correlated with ERAP1（r_s=-0.383,P=0.018）.There was no significant difference in fluorescence IOD values between HLA-C and ERAP1（r_s=-0.012,P=0.943）.Conclusion1.The expressions of IL-36α、ERAP1、CARD14 and STAT3 were the highest in ApoE^-/-+IMQ group,suggesting that these genes and inflammatory factors may play an important role in the pathogenesis of psoriasis with abnormal lipid metabolism.2.The positive cell ratio and the average protein expression intensity IOD values of HLA-C、ERAP1 and CD1a were highly expressed in PsV group,suggesting that antigen presentation related genes HLA-C、ERAP1 and CD1a may play a role in the pathogenesis of PsV.3.The protein expression intensity of HLA-C and CD1a was positively correlated in PsV group;The expression intensity of ERAP1 and CD1a was negatively correlated in PsV group.