Objective To observe the expression of miR-142-5p and forkhead transcription protein O subgroup 3 (FOXO3) in CD4⁺ T cells of experimental autoimmune uveitis (EAU) model rats, and preliminarily explore the targeting relationship between the two and the effect on EAU impact.Methods Ten Lewis rats were randomly divided into model group and control group. Rats in the model group wree induced an EAU animal model by adoptive immunization. Twenty days after immunization, CD4⁺ T cells were extracted from the eyeballs and draining lymph nodes of rats in the control group and model group, and divided into control group, model group, mimic-negative control (NC) group, miR-142-5p-mimic group, and small interference (si)-NC group, si-FOXO3 group for in vitro experiments. The miR-142-5p-mimic group and si-FOXO3 group were transfected with miR-142-5p-mimic and si-FOXO3, respectively. Twenty-five Lewis rats were randomly divided into model group, mimic-NC transfected group, miR-142-5p-mimic transfected group, si-NC transfected group, and si-FOXO3 transfected group. The above-mentioned in vitro experimental groups were injected with cells respectively. Slit lamp microscopy and EAU score were performed on 4, 8, 12, 16, 20 days after immunization; on 20 days after immunization, hematoxylin-eosin staining was performed for histopathological grading. Real-time fluorescence quantitative polymerase chain reaction was used to detect the relative expression of miR-142-5p and FOXO3 mRNA in CD4⁺ T cells and eye tissues of rats in each group, and helper T cell 17 (Th17) marker interleukin (IL)-17, IL-22, retinoic acid-related orphan receptor gamma (ROR gamma) relative expression level in the supernatant. Bioinformatics website and dual luciferase was used to predict the targeting relationship between miR-142-5p and FOXO3. One-way analysis of variance or t test was used for comparison between groups.Results All rats in the model group showed symptoms of EAU to varying degrees, and the symptoms became worse with time. Compared with the control group, the relative expression of miR-142-5p mRNA in CD4⁺ T cells of the model group increased, and the relative expression of FOXO3 mRNA decreased. The differences were statistically significant (t=7.374, 10.423; P=0.002, 0.001). Compared with the mimic-NC group, the relative expression of miR-142-5p mRNA in the CD4⁺ T cells of the miR-142-5p-mimic group increased, and the difference was statistically significant (t=6.540, P=0.003). Compared with the model group, mimic-NC group, and si-NC group, the relative expression of IL-17, IL-22, and RORγ mRNA in CD4⁺ T cells in the miR-142-5p-mimic group and si-FOCO3 group increased significantly. The difference was statistically significant (F=26.110, 6.292, 5.269, 55.660, 10.490, 11.430; P＜0.05). Compared with the mimic-NC transfected group, the relative expression of miR-142-5p mRNA in the ocular tissues of the miR-142-5p-mimic transfected rats increased significantly, and the difference was statistically significant (t=6.690, P＜0.05). Compared with the transfected si-NC group, the relative expression of FOXO3 mRNA in the eye tissue of the transfected si-FOXO3 group was significantly decreased, and the difference was statistically significant (t=17.751, P＜0.05). Rats in the mimic-NC transfected group, miR-142-5p-mimic transfected group, si-NC transfected group, and si-FOXO3 transfected group prolonged with time after immunization, and the EAU scores showed an upward trend. The EAU score and histopathological grade of rats in the miR-142-5p-mimic transfected group were higher than those in the mimic-NC transfected group, and the difference was statistically significant (t=5.633, 6.286; P＜0.05). The EAU score and histopathological grade of the rats in the transfected si-FOXO3 group were higher than those in the transfected si-NC group, and the difference was statistically significant (t=6.852, 6.635; P＜0.05). FOXO3 has a targeting relationship with miR-142-5p.Conclusions In EAU rat CD4⁺ T cells, the expression of miR-142-5p is up-regulated, while the expression of FOXO3 is down-regulated. miR-142-5p targets the expression of FOXO3 to promote the development of Th17 cell-related inflammatory factors.

Citation： Li Yuan, Qin Tingyu, Guo Long, Li Shuzhen, Hou Xiwu. miR-142-5p target regulation of forkhead transcription protein O subfamily 3 mediateing helper T cell 17 cell inflammation reaction promotes the development of autoimmune uveitis. Chinese Journal of Ocular Fundus Diseases, 2021, 37(7): 533-541. doi: 10.3760/cma.j.cn511434-20201203-00602 Copy