Down-regulation of miR-143-3p and decrease of Treg cells in CIA mice
To further confirm our findings, CIA model mice, which has a similar pathological mechanism to that of human RA[20,31], were successfully established to evaluate the relationship between miR-143-3p and Treg cells in vivo. Compared to those in WT mice, the arthritis score, paw swelling, histopathologic scores, TRAP-positive multinucleated cells, and inflammatory cytokine expression in CIA mice markedly increased (Figure 3-4). While a notable decline in the expression of miR-143-3p was detected in the splenic CD4+T cells of CIA mice (Figure 3A). As reported in previous studies[32], the differentiation of Treg cells both in blood and spleen and the expression of Foxp3 in spleen and axillary lymph nodes (ALNs) markedly decreased in CIA mice compared to the control (Figure 5). These results suggest a possible positive effect of miR-143-3p on Treg differentiation and RA pathogenesis.