Selenium regulates T cell differentiation in experimental autoimmune thyroiditis in mice

Selenium (Se) is an essential trace element that plays an important role in thyroid physiology. Se supplementation can reduce levels of autoimmune thyroid antibodies, which may be beneficial in Hashimoto's thyroiditis (HT). However, the long-term benefits of Se supplementation for HT patients are controversial and there is no clear clinical evidence to support it, so further basic and clinical research is needed. The effect of Se on immune cells, especially T cells, in autoimmune thyroiditis (AIT) has not been elucidated. Here, we replicated a mouse model of experimental autoimmune thyroiditis (EAT) on a high-iodine diet and treated it with Se supplementation. At week 8 of the experiment, Se supplementation reduced the destruction of thyroid follicles and the infiltration rate of lymphocytes in EAT mice, and reversed the disturbance of peripheral blood thyroxine and thyroid autoantibody levels. Further examination revealed that Se had broad effects on T-cell subsets. Its effects include reducing the production of pro-inflammatory cytokines by Th1 cells, inhibiting the differentiation and production of cytokines by Th2 and Th17 cells, and upregulating the differentiation and production of cytokines by Treg cells. These changes help alleviate thyroid follicle damage during EAT. In conclusion, selenium supplementation has the potential to improve the prognosis of AIT by altering the subset differentiation and/or function of CD4+ T cells.

Leptin receptor antagonist attenuates experimental autoimmune thyroiditis in mice by regulating Treg/Th17 cell differentiation

Leptin has been found to be involved in the development and progression of many autoimmune diseases. As an organ-specific autoimmune disease, the pathogenesis of Hashimoto's thyroiditis has not been fully elucidated. It has been reported that serum leptin level is increased in Hashimoto's thyroiditis, but other studies have not shown any difference. We replicated a mouse model of experimental autoimmune thyroiditis (EAT) with a high-iodine diet and found that injection of the leptin receptor antagonist Allo-aca reduced thyroid follicle destruction and inflammatory cell infiltration in EAT mice, and thyroxine and thyroid autoimmune antibody levels. Further investigation revealed that Allo-aca promotes the differentiation of Treg cells and inhibits the differentiation of Th17 cells. We believe that Allo-aca can alter the differentiation of Treg/Th17 cells by inhibiting the leptin signaling pathway, thereby alleviating thyroid injury in EAT mice. Interfering with the leptin signaling pathway may be a novel new approach to treat treating and ameliorating Hashimoto's thyroiditis.