Abstract
BackgroundPrevious studies reported that various miRNAs participate in autoimmune diseases, but the potential regulatory mechanism of miRNAs in autoimmune thyroiditis (AIT) needs further exploration.ObjectiveThis study aimed to further verify that miR-326 contributes to AIT by regulating Th17/Treg balance through Ets-1 using lentiviral gene delivery through tail vein and thyroid injection in NOD.H-2h4 mice.Materials and MethodsFive-week-old NOD.H-2h4 mice were divided randomly into tail vein and thyroid injection groups, and each received either mmu-miR-326 sponge (LV-sponge) or lentiviral vector control. Mice were divided for tail vein injection: the therapeutic LV-ctrl, therapeutic LV-sponge, prophylactic LV-ctrl, and prophylactic LV-sponge groups. The control group was fed high-iodine water without vein injection. The thyroid infiltration of lymphocytes and serum TgAb value were investigated by thyroid hematoxylin and eosin (HE) staining and ELISA, respectively. Ets-1 and lymphocyte counts were measured by RT-PCR, western blotting, and flow cytometry. The thyroid CD4+IL-17a+ cells and CD4+Ets-1+ cells were detected by immunofluorescence, and the serum cytokines were tested by ELISA.ResultsIn the tail vein injection groups, the thyroid inflammatory score and serum TgAb titer were significantly lower in the LV-sponge groups than in the control and LV-ctrl groups while Ets-1 protein expression in mouse spleens was increased in the LV-sponge groups. Moreover, Th17/Treg ratio declined in the LV-sponge group and decreased significantly in the prophylactic LV-sponge group (P = 0.036) tested by flow cytometry. Immunofluorescence showed that, in LV-sponge groups, CD4+IL-17a+ cells were decreased significantly (P = 0.001), while CD4+Ets-1+ cells were increased significantly in the LV-sponge group (P = 0.029). The serum IL-17/IL-10 was decreased significantly in the LV-sponge group (P < 0.05). In the thyroid injection groups, the thyroid inflammatory score and serum TgAb titer in the LV-sponge group decreased significantly compared with those in the LV-ctrl group (P < 0.05). In addition, in LV-sponge groups, CD4+IL-17a+ cells were decreased, while CD4+Ets-1+ cells were increased significantly in the inhibition group evaluated by immunofluorescence. Moreover, tail vein injection of LV-sponge resulted in much lower TgAb levels in thyroiditis compared with thyroid injection.ConclusionMiR-326 targeted therapy may be a promising approach for AIT. In addition, tail vein injection may achieve a better intervention effect than thyroid injection.
Highlights
Autoimmune thyroiditis (AIT), a type of autoimmune thyroid disease (AITD), mainly includes Hashimoto’s thyroiditis (HT), atrophy thyroiditis, and Riedel thyroiditis
The results showed that the counts of T cells, B cells, cytotoxic T (Tc) cells, and helper T (Th) cells in LV-sponge groups were not different from those in the control group and lentivirus-specific control (LV-ctrl) groups, suggesting that the in vivo intervention by lentivirus had no effect on the balances of T and B cell groups and Th and Tc cell subgroups in mice (Figure 1)
In systemic sclerosis (SSc), scholars have found that microRNA-27a-3p targeting sFRP-1, a negative regulator of Wnt signaling, in dermal fibroblasts mediates fibrosis regression [25]
Summary
Autoimmune thyroiditis (AIT), a type of autoimmune thyroid disease (AITD), mainly includes Hashimoto’s thyroiditis (HT), atrophy thyroiditis, and Riedel thyroiditis. The thyroid glands of patients with AIT undergo lymphocyte infiltration and thyroid follicular destruction. Circulating serum autoantibodies such as thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TgAb) in HT patients lead to thyroid atrophy or fibrosis accompanied by hypothyroidism [1, 2]. It has been reported that environmental factors trigger the occurrence of AIT in a genetic background. Previous studies reported that various miRNAs participate in autoimmune diseases, but the potential regulatory mechanism of miRNAs in autoimmune thyroiditis (AIT) needs further exploration
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
