Abstract: 【Abstract】 Objective To determine the expression of miRNA-148a-3p in CD4⁺ T lymphocytes in peripheral blood of patients with psoriasis vulgaris, and to explore its role in occurrence of psoriasis vulgaris. Methods Totally, 20 patients with psoriasis vulgaris and 20 healthy controls were enrolled from Guangzhou Institute of Dermatology between July 2017 and April 2018. Peripheral venous blood samples were obtained from these subjects, and CD4⁺ T lymphocytes were isolated from these peripheral blood samples by magnetic cell sorting system. Real-time quantitative PCR （RT-PCR） was performed to determine the expression of miRNA-148a-3p in CD4⁺ T lymphocytes in the peripheral blood. Potential target genes of miRNA-148a were predicted by using bioinformatics software, and verified by using a dual-luciferase reporter system. Western blot analysis was conducted to determine the protein expression of Bcl-2 interacting mediator of cell death （Bim, the potential target gene of miRNA-148a-3p） in the CD4⁺ T lymphocytes of the subjects. Statistical analysis was carried out with SPSS 20 software by two sample-t test for comparing the means of normally distributed data, and by Pearson correlation analysis for analyzing the correlation of two variables. If the data were not normally distributed, Mann Whitney U test was used for comparing means between two groups, and Spearman correlation analysis for analyzing the correlation of two variables. Results The miRNA-148a-3p expression in the CD4⁺ T lymphocytesin the psoriasis vulgaris group （18 cases, 5.61 ± 1.66） was significantly higher than that in the healthy control group （12 cases, 1.00 ± 0.26; U = 12, P < 0.05）, and was positively correlated with the psoriasis area severity index （PASI） score （r = 0.93, P < 0.001）. Bim was predicted to be one of the potential target genes of miRNA-148a-3p by bioinformatics software, which was also verified by using a dual-luciferase reporter system. The protein expression of Bim in the CD4⁺ T lymphocytes was significantly lower in the psoriasis vulgaris group （11 cases, 0.69 ± 0.07） than in the healthy control group （8 cases, 0.93 ± 0.06; t = 4.38, P < 0.01）, and the protein expression of Bim in the patients with psoriasis vulgaris was negatively correlated with PASI score （r = -0.774, P < 0.01）. Conclusion miRNA-148a-3p is overexpressed in CD4⁺ T cells in the peripheral blood of patients with psoriasis vulgaris, which may regulate the protein expression of Bim, leading to abnormal activation of CD4⁺ T cells, and then participate in the occurrence and development of psoriasis.

Key words: Psoriasis, MicroRNAs, CD4?positive T-lymphocytes, microRNA-148a-3p, Bim