Ebosin Ameliorates Psoriasis-Like Inflammation of Mice miR-155 Targeting on IL-17 Pathway.

Psoriasis is a recurrent autoimmune skin disease with aberrant regulation of keratinocytes and immunocytes. There is no universally accepted single treatment available for psoriasis, and the establishment of a common treatment option to control its signs and symptoms is urgently needed. Here, we found Ebosin, a novel exopolysaccharide isolated from sp. 139 by our lab, not only could ameliorate inflammation in LPS-induced keratinocytes through IKK/NF-kapaB pathway, but also attenuate psoriatic skin lesions and reduce inflammatory factors expression in imiquimod (IMQ)-mediated psoriatic mice. Except for inhibiting the expression of epidermal differentiation related proteins, Ebosin significantly increased the percentage of CD4Foxp3CD25 Tregs and decreased CD4IL17A Th17 cells in psoriatic mice. Furthermore, we demonstrate that Ebosin significantly suppressed the IL-17 signaling pathway A20 (encoded by ) . As the direct binding of to miR-155 has been demonstrated by luciferase reporter assay, and Ebosin has been demonstrated to inhibit miR-155 level and , our study first indicates that Ebosin reduces inflammation through the miR-155--IL-17 axis and T cell differentiation in a psoriasis-like model. Thus, we conclude that Ebosin can act as a promising therapeutic candidate for the treatment of psoriasis.