%0 Journal Article %T Correlation between the Frequency of Th17 Cell and the Expression of MicroRNA-206 in Patients with Dermatomyositis %A Xinyi Tang %A Xinyu Tian %A Yue Zhang %A Wei Wu %A Jie Tian %A Ke Rui %A Jia Tong %A Liwei Lu %A Huaxi Xu %A Shengjun Wang %J Journal of Immunology Research %D 2013 %R 10.1155/2013/345347 %X It was reported that IL-17 had been detected in the inflammatory infiltrates of patients with DM (dermatomyositis). In this study, we investigated the frequency of Th17 cells and the expression of microRNA-206 (miR-206) in DM patients. Firstly, we observed that the frequency of Th17 cells and the expression of transcription factors were increased significantly in the PBMCs of DM patients. Secondly, we found that there was a positive correlation between the percentages of Th17 cells and serum level of CK in DM patients. And the serum concentrations of IL-6, IL-1¦Â, TGF-¦Â, and IL-23, the important cytokines of Th17 differentiation, were increased in DM patients. It was predicted that Kr¨¹ppel-like factor 4 (KLF4) is one of the multiple targets of miR-206. We detected the expression of miR-206 in DM patients, and it was decreased in the serum and PBMCs of DM patients. The augmented expression of KLF is accompanied by the attenuated expression of miR-206. Furthermore, a negative correlation between the percentages of Th17 cells and the expression of miR-206 in DM patients has been found. Taken together, these findings suggest the attenuated expression of miR-206, and the augmented frequency of Th17 cells in DM patients. 1. Introduction DM (dermatomyositis) is a subtype of inflammatory myopathies, which is a rare autoimmune disease of skeletal muscle. Patients with DM typically experience the symmetric proximal muscle weakness, electromyographic and muscle alteration, characteristic skin lesion, and elevation of muscle enzymes such as creatine kinase (CK) or lactate dehydrogenase (LDH). Therefore, these clinical symptoms are current diagnostic criteria for DM [1, 2]. Although the pathogenic mechanism of DM is still unclear, it was considered as a CD4+T cells driven disease [3, 4]. On the basis of cytokine expression, CD4+ helper T cells were classified into Th1, Th2, regulatory T cells, and Th17 cells [5]. Early study demonstrated that Th17 cells participate in host defense against extracellular bacteria and fungi. Furthermore, it was observed that Th17 cells are also involved in the process of several inflammatory and autoimmune diseases, such as autoimmune arthritis, Crohn¡¯s disease, multiple sclerosis, psoriasis, and Hashimoto¡¯s thyroiditis [6¨C12]. Recent study elucidated that some proinflammatory cytokines such as IL-6, IL-1 , TGF- , and IL-23 are critical factors functioning during the process of Th17 cells differentiation [13¨C16]. It was reported that IL-17, a key cytokine of Th17 cells, had been detected in the inflammatory infiltrates of patients with %U http://www.hindawi.com/journals/jir/2013/345347/